jueves, 13 de junio de 2019

Chronic Myeloproliferative Neoplasms Treatment (PDQ®)—Health Professional Version - National Cancer Institute

Chronic Myeloproliferative Neoplasms Treatment (PDQ®)—Health Professional Version - National Cancer Institute

National Cancer Institute



Chronic Myeloproliferative Neoplasms Treatment (PDQ®)–Health Professional Version

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General Information About Chronic Myeloproliferative Neoplasms (MPN)

The chronic MPN consist of chronic myelogenous leukemia, polycythemia vera (p. vera), primary myelofibrosis, essential thrombocythemia, chronic neutrophilic leukemia, and chronic eosinophilic leukemia. All of these disorders involve dysregulation at the multipotent hematopoietic stem cell (CD34), with one or more of the following shared features:
  • Overproduction of one or several blood elements with dominance of a transformed clone.
  • Hypercellular marrow/marrow fibrosis.
  • Cytogenetic abnormalities.
  • Thrombotic and/or hemorrhagic diatheses.[1]
  • Extramedullary hematopoiesis (liver/spleen).
  • Transformation to acute leukemia.
  • Overlapping clinical features.
Chronic MPN usually occur sporadically; however, familial clusters of MPN have been reported. These familial clusters include autosomal-dominant inheritance and autosomal-recessive inheritance.[2] Patients with p. vera and essential thrombocythemia have marked increases of red blood cell and platelet production, respectively. Treatment is directed at reducing the excessive numbers of blood cells. Both p. vera and essential thrombocythemia can develop a spent phase late in their courses that resembles primary myelofibrosis with cytopenias and marrow hypoplasia and fibrosis.[3-5] A specific point mutation in one copy of the Janus kinase 2 gene (JAK2), a cytoplasmic tyrosine kinase, on chromosome 9, which causes increased proliferation and survival of hematopoietic precursors in vitro, has been identified in most patients with p. vera, essential thrombocythemia, and idiopathic myelofibrosis.[6-11] Researchers are pursuing specific targeting of this aberrant protein as well as new targets based on next-generation sequencing of the genome.[12] Other somatic activating mutations have been identified, including the myeloproliferative leukemia (MPL) exon 10 and the calreticulin (CALR) gene in patients with essential thrombocythemia and primary myelofibrosis.[13-15]
Leukemic transformation from Philadelphia chromosome–negative myeloproliferative neoplasms is defined as having 20% or greater myeloblasts in the blood or marrow (MPN-blast phase) and having no standard approach and a poor prognosis (3- to 5-month median survival).[16] Allogeneic stem cell transplantation has resulted in anecdotal long-term survivors, but this approach is often not feasible in older patients with comorbid conditions or lack of initial response to leukemic induction therapy.[17]
References
  1. Hultcrantz M, Björkholm M, Dickman PW, et al.: Risk for Arterial and Venous Thrombosis in Patients With Myeloproliferative Neoplasms: A Population-Based Cohort Study. Ann Intern Med 168 (5): 317-325, 2018. [PUBMED Abstract]
  2. Ranjan A, Penninga E, Jelsig AM, et al.: Inheritance of the chronic myeloproliferative neoplasms. A systematic review. Clin Genet 83 (2): 99-107, 2013. [PUBMED Abstract]
  3. Schafer AI: Bleeding and thrombosis in the myeloproliferative disorders. Blood 64 (1): 1-12, 1984. [PUBMED Abstract]
  4. Barosi G: Myelofibrosis with myeloid metaplasia: diagnostic definition and prognostic classification for clinical studies and treatment guidelines. J Clin Oncol 17 (9): 2954-70, 1999. [PUBMED Abstract]
  5. Tefferi A: Myelofibrosis with myeloid metaplasia. N Engl J Med 342 (17): 1255-65, 2000. [PUBMED Abstract]
  6. Kralovics R, Passamonti F, Buser AS, et al.: A gain-of-function mutation of JAK2 in myeloproliferative disorders. N Engl J Med 352 (17): 1779-90, 2005. [PUBMED Abstract]
  7. Baxter EJ, Scott LM, Campbell PJ, et al.: Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disorders. Lancet 365 (9464): 1054-61, 2005 Mar 19-25. [PUBMED Abstract]
  8. James C, Ugo V, Le Couédic JP, et al.: A unique clonal JAK2 mutation leading to constitutive signalling causes polycythaemia vera. Nature 434 (7037): 1144-8, 2005. [PUBMED Abstract]
  9. Levine RL, Wadleigh M, Cools J, et al.: Activating mutation in the tyrosine kinase JAK2 in polycythemia vera, essential thrombocythemia, and myeloid metaplasia with myelofibrosis. Cancer Cell 7 (4): 387-97, 2005. [PUBMED Abstract]
  10. Scott LM, Tong W, Levine RL, et al.: JAK2 exon 12 mutations in polycythemia vera and idiopathic erythrocytosis. N Engl J Med 356 (5): 459-68, 2007. [PUBMED Abstract]
  11. Campbell PJ, Green AR: The myeloproliferative disorders. N Engl J Med 355 (23): 2452-66, 2006. [PUBMED Abstract]
  12. Grinfeld J, Nangalia J, Baxter EJ, et al.: Classification and Personalized Prognosis in Myeloproliferative Neoplasms. N Engl J Med 379 (15): 1416-1430, 2018. [PUBMED Abstract]
  13. Cazzola M, Kralovics R: From Janus kinase 2 to calreticulin: the clinically relevant genomic landscape of myeloproliferative neoplasms. Blood 123 (24): 3714-9, 2014. [PUBMED Abstract]
  14. Rumi E, Pietra D, Ferretti V, et al.: JAK2 or CALR mutation status defines subtypes of essential thrombocythemia with substantially different clinical course and outcomes. Blood 123 (10): 1544-51, 2014. [PUBMED Abstract]
  15. Rotunno G, Mannarelli C, Guglielmelli P, et al.: Impact of calreticulin mutations on clinical and hematological phenotype and outcome in essential thrombocythemia. Blood 123 (10): 1552-5, 2014. [PUBMED Abstract]
  16. Mascarenhas J, Heaney ML, Najfeld V, et al.: Proposed criteria for response assessment in patients treated in clinical trials for myeloproliferative neoplasms in blast phase (MPN-BP): formal recommendations from the post-myeloproliferative neoplasm acute myeloid leukemia consortium. Leuk Res 36 (12): 1500-4, 2012. [PUBMED Abstract]
  17. Alchalby H, Zabelina T, Stübig T, et al.: Allogeneic stem cell transplantation for myelofibrosis with leukemic transformation: a study from the Myeloproliferative Neoplasm Subcommittee of the CMWP of the European Group for Blood and Marrow Transplantation. Biol Blood Marrow Transplant 20 (2): 279-81, 2014. [PUBMED Abstract]

Chronic Myelogenous Leukemia

Refer to the PDQ summary on Chronic Myelogenous Leukemia Treatment for more information.

Polycythemia Vera

Disease Overview

The proposed revised World Health Organization criteria for the diagnosis of polycythemia vera (p. vera) requires two major criteria and one minor criterion or the first major criterion together with two minor criteria.[1]
Major Criteria
  1. Hemoglobin of more than 18.5 g/dL in men, 16.5 g/dL in women, or elevated red cell mass greater than 25% above mean normal predicted value.
  2. Presence of JAK2 V617F or other functionally similar mutations, such as the exon 12 mutation of JAK2.
Minor Criteria
  1. Bone marrow biopsy showing hypercellularity with prominent erythroid, granulocytic, and megakaryocytic proliferation.
  2. Serum erythropoietin level below normal range.
  3. Endogenous erythroid colony formation in vitro.
Other confirmatory findings no longer required for diagnosis include the following:[2-4]
  • Oxygen saturation with arterial blood gas greater than 92%.
  • Splenomegaly.
  • Thrombocytosis (>400,000 platelets/mm3).
  • Leukocytosis (>12,000/mm3).
  • Leukocyte alkaline phosphatase (>100 units in the absence of fever or infection).
There is no staging system for this disease.
Patients have an increased risk of cardiovascular and thrombotic events [5] and transformation to acute myelogenous leukemia or primary myelofibrosis.[6-8] Age older than 65 years, leukocytosis, and a history of vascular events (bleeding or thrombosis) are associated with a poor prognosis.[6,9,10]

Treatment Overview

The primary therapy for p. vera includes intermittent, chronic phlebotomy to maintain the hematocrit below 45%; this recommendation was confirmed in a randomized, prospective trial, which demonstrated lower rates of cardiovascular death and major thrombosis using this hematocrit target.[11,12] The target level for women may need to be lower (e.g., hematocrit <40%), but there are no empiric data to confirm this recommendation.[13]
Complications of phlebotomy include the following:
  • Progressive and sometimes extreme thrombocytosis and symptomatology related to chronic iron deficiency, including pica, angular stomatitis, and glossitis.
  • Dysphagia that is the result of esophageal webs (very rare).
  • Possibly muscle weakness.
(Refer to the PDQ summary on Oral Complications of Chemotherapy and Head/Neck Radiation for more information.)
In addition, progressive splenomegaly or pruritus not controllable by antihistamines may persist despite control of the hematocrit by phlebotomy. (Refer to the PDQ summary on Pruritus for more information.) If phlebotomy becomes impractical, hydroxyurea or interferon-alpha can be added to control the disease.
The Polycythemia Vera Study Group randomly assigned more than 400 patients to phlebotomy (target hematocrit <45), radioisotope phosphorous 32 (32P) (2.7 mg/m2administered intravenously every 12 weeks as needed), or chlorambucil (10 mg administered by mouth daily for 6 weeks, then given daily on alternate months).[14] The median survival for the phlebotomy group (13.9 years) and the radioisotope 32P group (11.8 years) was significantly better than that of the chlorambucil group (8.9 years), primarily because of excessive late deaths from leukemia or other hematologic malignancies.[14][Level of evidence: 1iiA] Because of these concerns, many clinicians use hydroxyurea for patients who require cytoreductive therapy that is caused by massive splenomegaly, a high phlebotomy requirement, or excessive thrombocytosis.[14]
In a pooled analysis of 16 different trials, interferon-alpha therapy resulted in avoidance of phlebotomy in 50% of patients, with 80% of patients experiencing marked reduction of splenomegaly.[15][Level of evidence: 3iiiDiv] Interferon posed problems of cost, side effects, and parenteral route of administration, but no cases of acute leukemia were seen in this analysis. When patients are poorly compliant with phlebotomy or issues of massive splenomegaly, leukocytosis, or thrombocytosis supervene, treatment with interferon or pegylated interferon is considered for patients younger than 50 years (who are more likely to tolerate the side effects and benefit from a lack of transformation to leukemia), while hydroxyurea is considered for patients older than 50 years.[2,16,17]
Patients who required therapy with hydroxyurea but had either an inadequate response or unacceptable side effects were randomly assigned to receive ruxolitinib or standard therapy (interferon, chlorambucil, or busulfan). Ruxolitinib provided better control of hematocrit (60% vs. 20%, P < .001), reduction of spleen volume (38% vs. 1%, P < .001) and reduction of symptom score by 50% (49% vs. 5%, P < .001).[18][Level of evidence: 1iiDiv]
Patients with p. vera and no splenomegaly in whom hydroxyurea failed were studied in a randomized prospective trial of 173 participants.[19] Patients were randomly assigned to receive ruxolitinib (the JAK2 inhibitor) versus best available therapy (such as interferon, higher doses of hydroxyurea, or no treatment). Hematocrit control was achieved in 62% of ruxolitinib-treated patients versus 19% of controls (hazard ratio, 7.28; 95% confidence interval [CI], 3.43‒15.45, P < .001).[19][Level of evidence: 1iiDiv]
In a Cochrane review of two randomized studies of 630 patients with no clear indication or contraindication for aspirin, those receiving 100 mg of aspirin versus placebo had reduction of fatal thrombotic events, but this benefit was not statistically significant (odds ratio, 0.20; 95% CI, 0.03–1.14).[20] A retrospective review of 105 patients who underwent surgery documented that 8% of them had thromboembolisms and 7% of them had major hemorrhages with previous cytoreduction by phlebotomy and postoperative subcutaneous heparin in one half of the patients.[21]
Guidelines based on anecdotal reports have been developed for the management of pregnant patients with p. vera.[3]
Treatment options include the following:
  1. Phlebotomy.[11]
  2. Hydroxyurea (alone or with phlebotomy).[13,14]
  3. Interferon-alpha [15,22-24] and pegylated interferon-alpha.[25,26]
  4. Rarely, chlorambucil or busulfan may be required, especially if interferon or hydroxyurea are not tolerated, as is often seen in patients older than 70 years.[2]
  5. Low-dose aspirin (≤100 mg) daily, unless contraindicated by major bleeding or gastric intolerance.[9,20]

Current Clinical Trials

Use our advanced clinical trial search to find NCI-supported cancer clinical trials that are now enrolling patients. The search can be narrowed by location of the trial, type of treatment, name of the drug, and other criteria. General information about clinical trials is also available.
References
  1. Tefferi A, Thiele J, Vardiman JW: The 2008 World Health Organization classification system for myeloproliferative neoplasms: order out of chaos. Cancer 115 (17): 3842-7, 2009. [PUBMED Abstract]
  2. Streiff MB, Smith B, Spivak JL: The diagnosis and management of polycythemia vera in the era since the Polycythemia Vera Study Group: a survey of American Society of Hematology members' practice patterns. Blood 99 (4): 1144-9, 2002. [PUBMED Abstract]
  3. McMullin MF, Bareford D, Campbell P, et al.: Guidelines for the diagnosis, investigation and management of polycythaemia/erythrocytosis. Br J Haematol 130 (2): 174-95, 2005. [PUBMED Abstract]
  4. Campbell PJ, Green AR: The myeloproliferative disorders. N Engl J Med 355 (23): 2452-66, 2006. [PUBMED Abstract]
  5. Hultcrantz M, Björkholm M, Dickman PW, et al.: Risk for Arterial and Venous Thrombosis in Patients With Myeloproliferative Neoplasms: A Population-Based Cohort Study. Ann Intern Med 168 (5): 317-325, 2018. [PUBMED Abstract]
  6. Marchioli R, Finazzi G, Landolfi R, et al.: Vascular and neoplastic risk in a large cohort of patients with polycythemia vera. J Clin Oncol 23 (10): 2224-32, 2005. [PUBMED Abstract]
  7. Elliott MA, Tefferi A: Thrombosis and haemorrhage in polycythaemia vera and essential thrombocythaemia. Br J Haematol 128 (3): 275-90, 2005. [PUBMED Abstract]
  8. Chait Y, Condat B, Cazals-Hatem D, et al.: Relevance of the criteria commonly used to diagnose myeloproliferative disorder in patients with splanchnic vein thrombosis. Br J Haematol 129 (4): 553-60, 2005. [PUBMED Abstract]
  9. Finazzi G, Barbui T: How I treat patients with polycythemia vera. Blood 109 (12): 5104-11, 2007. [PUBMED Abstract]
  10. Bonicelli G, Abdulkarim K, Mounier M, et al.: Leucocytosis and thrombosis at diagnosis are associated with poor survival in polycythaemia vera: a population-based study of 327 patients. Br J Haematol 160 (2): 251-4, 2013. [PUBMED Abstract]
  11. Berk PD, Goldberg JD, Donovan PB, et al.: Therapeutic recommendations in polycythemia vera based on Polycythemia Vera Study Group protocols. Semin Hematol 23 (2): 132-43, 1986. [PUBMED Abstract]
  12. Marchioli R, Finazzi G, Specchia G, et al.: Cardiovascular events and intensity of treatment in polycythemia vera. N Engl J Med 368 (1): 22-33, 2013. [PUBMED Abstract]
  13. Lamy T, Devillers A, Bernard M, et al.: Inapparent polycythemia vera: an unrecognized diagnosis. Am J Med 102 (1): 14-20, 1997. [PUBMED Abstract]
  14. Kaplan ME, Mack K, Goldberg JD, et al.: Long-term management of polycythemia vera with hydroxyurea: a progress report. Semin Hematol 23 (3): 167-71, 1986. [PUBMED Abstract]
  15. Lengfelder E, Berger U, Hehlmann R: Interferon alpha in the treatment of polycythemia vera. Ann Hematol 79 (3): 103-9, 2000. [PUBMED Abstract]
  16. Kiladjian JJ, Cassinat B, Chevret S, et al.: Pegylated interferon-alfa-2a induces complete hematologic and molecular responses with low toxicity in polycythemia vera. Blood 112 (8): 3065-72, 2008. [PUBMED Abstract]
  17. Masarova L, Patel KP, Newberry KJ, et al.: Pegylated interferon alfa-2a in patients with essential thrombocythaemia or polycythaemia vera: a post-hoc, median 83 month follow-up of an open-label, phase 2 trial. Lancet Haematol 4 (4): e165-e175, 2017. [PUBMED Abstract]
  18. Vannucchi AM, Kiladjian JJ, Griesshammer M, et al.: Ruxolitinib versus standard therapy for the treatment of polycythemia vera. N Engl J Med 372 (5): 426-35, 2015. [PUBMED Abstract]
  19. Passamonti F, Griesshammer M, Palandri F, et al.: Ruxolitinib for the treatment of inadequately controlled polycythaemia vera without splenomegaly (RESPONSE-2): a randomised, open-label, phase 3b study. Lancet Oncol 18 (1): 88-99, 2017. [PUBMED Abstract]
  20. Squizzato A, Romualdi E, Passamonti F, et al.: Antiplatelet drugs for polycythaemia vera and essential thrombocythaemia. Cochrane Database Syst Rev 4: CD006503, 2013. [PUBMED Abstract]
  21. Ruggeri M, Rodeghiero F, Tosetto A, et al.: Postsurgery outcomes in patients with polycythemia vera and essential thrombocythemia: a retrospective survey. Blood 111 (2): 666-71, 2008. [PUBMED Abstract]
  22. Silver RT: Long-term effects of the treatment of polycythemia vera with recombinant interferon-alpha. Cancer 107 (3): 451-8, 2006. [PUBMED Abstract]
  23. Quintás-Cardama A, Kantarjian HM, Giles F, et al.: Pegylated interferon therapy for patients with Philadelphia chromosome-negative myeloproliferative disorders. Semin Thromb Hemost 32 (4 Pt 2): 409-16, 2006. [PUBMED Abstract]
  24. Huang BT, Zeng QC, Zhao WH, et al.: Interferon α-2b gains high sustained response therapy for advanced essential thrombocythemia and polycythemia vera with JAK2V617F positive mutation. Leuk Res 38 (10): 1177-83, 2014. [PUBMED Abstract]
  25. Quintás-Cardama A, Kantarjian H, Manshouri T, et al.: Pegylated interferon alfa-2a yields high rates of hematologic and molecular response in patients with advanced essential thrombocythemia and polycythemia vera. J Clin Oncol 27 (32): 5418-24, 2009. [PUBMED Abstract]
  26. Quintás-Cardama A, Abdel-Wahab O, Manshouri T, et al.: Molecular analysis of patients with polycythemia vera or essential thrombocythemia receiving pegylated interferon α-2a. Blood 122 (6): 893-901, 2013. [PUBMED Abstract]

Primary Myelofibrosis

Disease Overview

Primary myelofibrosis (also known as agnogenic myeloid metaplasia, chronic idiopathic myelofibrosis, myelosclerosis with myeloid metaplasia, and idiopathic myelofibrosis) is characterized by splenomegaly, immature peripheral blood granulocytes and erythrocytes, and teardrop-shaped red blood cells.[1] In its early phase, the disease is characterized by elevated numbers of CD34-positive cells in the marrow, while the later phases involve marrow fibrosis with decreasing CD34 cells in the marrow and a corresponding increase in splenic and liver engorgement with CD34 cells.
As distinguished from chronic myelogenous leukemia (CML), primary myelofibrosis usually presents as follows:[2]
  • A white blood cell count smaller than 30,000/mm3.
  • Prominent teardrops on peripheral smear.
  • Normocellular or hypocellular marrow with moderate to marked fibrosis.
  • An absence of the Philadelphia chromosome or the BCR/ABL translocation.
  • Frequent positivity for the JAK2 mutation, the myeloproliferative leukemia (MPL) mutation, or the calreticulin (CALR) gene mutation (identifying 70% of patients).[3-5]
In addition to the clonal proliferation of a multipotent hematopoietic progenitor cell, an event common to all chronic myeloproliferative neoplasms, myeloid metaplasia is characterized by colonization of extramedullary sites such as the spleen or liver.[6,7]
Most patients are older than 60 years at diagnosis, and 33% of patients are asymptomatic at presentation. Splenomegaly, sometimes massive, is a characteristic finding.
Symptoms include the following:
  • Splenic pain.
  • Early satiety.
  • Anemia.
  • Bone pain.
  • Fatigue.
  • Fever.
  • Night sweats.
  • Weight loss.
(Refer to the PDQ summaries on Cancer Pain; Fatigue; Hot Flashes and Night Sweats; and Nutrition for information on many of the symptoms listed above.)
The proposed World Health Organization criteria for the diagnosis of primary myelofibrosis requires all three major criteria and two minor criteria.[8]
Major Criteria
  1. Presence of megakaryocyte proliferation and atypia, usually accompanied by either reticulin and/or collagen fibrosis; or, in the absence of significant reticulin fibrosis, the megakaryocyte changes must be accompanied by increased bone marrow cellularity characterized by granulocytic proliferation and often decreased erythropoiesis (so-called prefibrotic cellular-phase disease).
  2. Not meeting criteria for polycythemia vera (p. vera), CML, myelodysplastic syndrome, or other myeloid neoplasm.
  3. Demonstration of JAK2 V617F or other clonal marker; or, in the absence of a clonal marker, no evidence of bone marrow fibrosis caused by an underlying inflammatory disease or another neoplastic disease. About 60% of patients with primary myelofibrosis carry a JAK2 mutation, and about 5% to 10% of the patients have activating mutations in the thrombopoietin receptor gene, MPL. More than half of the patients without JAK2 or MPL carry a somatic mutation of the CALR gene, which is associated with a more indolent clinical course than is seen with JAK2 or MPLmutations.[3-5,9-11]
Minor Criteria
  1. Leukoerythroblastosis.
  2. Increased serum level of lactate dehydrogenase.
  3. Anemia.
  4. Palpable splenomegaly.
The median survival is 3.5 years to 5.5 years, but patients younger than 55 years have a median survival of 11 years.[6,7] The major causes of death include the following:[12]
  • Progressive marrow failure.
  • Transformation to acute nonlymphoblastic leukemia.[13]
  • Infection.
  • Thrombohemorrhagic events.[14]
  • Heart failure.
  • Portal hypertension.
Fatal and nonfatal thrombosis was associated with age older than 60 years and JAK2 V617F positivity in a multivariable analysis of 707 patients followed from 1973 to 2008.[15] Bone marrow examination including cytogenetic testing may exclude other causes of myelophthisis, such as CML, myelodysplastic syndrome, metastatic cancer, lymphomas, and plasma cell disorders.[7] In acute myelofibrosis, patients present with pancytopenia but no splenomegaly or peripheral blood myelophthisis. Peripheral blood or marrow monocytosis is suggestive for myelodysplasia in this setting.
There is no staging system for this disease.
Prognostic factors include the following:[16-20]
  • Age 65 years or older.
  • Anemia (hemoglobin <10 g/dL).
  • Constitutional symptoms: fever, night sweats, or weight loss.
  • Leukocytosis (white blood cell count >25 × 109/L).
  • Circulating blasts of at least 1%.
Patients without any of the adverse features, excluding age, have a median survival of more than 10 to 15 years, but the presence of any two of the adverse features lowers the median survival to less than 4 years.[21,22] International prognostic scoring systems incorporate the aforementioned prognostic factors.[21,23]
Karyotype abnormalities can also affect prognosis. In a retrospective series, the 13q and 20q deletions and trisomy 9 correlated with improved survival and no leukemia transformation in comparison with the worse prognosis with trisomy 8, complex karyotype, -7/7q-, i(17q), inv(3), -5/5q-, 12p-, or 11q23 rearrangement.[15,24]

Treatment Overview

Asymptomatic low-risk patients (based on the aforementioned prognostic systems) should be monitored with a watchful waiting approach. The development of symptomatic anemia, marked leukocytosis, drenching night sweats, weight loss, fever, or symptomatic splenomegaly would warrant therapeutic intervention.
The profound anemia that develops in this disease usually requires red blood cell transfusion. Red blood cell survival is markedly decreased in some patients; this can sometimes be treated with glucocorticoids. Disease-associated anemia may occasionally respond to the following:[7,25-27]
  • Erythropoietic growth factors. Erythropoietin and darbepoetin are less likely to help when patients are transfusion dependent or manifest a serum erythropoietin level greater than 125 U/L.[28,29]
  • Prednisone (40–80 mg/day).
  • Danazol (600 mg/day).
  • Thalidomide (50 mg/day) with or without prednisone.[30] Patients on thalidomide require prophylaxis for avoiding thrombosis and careful monitoring for hematologic toxicity.
  • Lenalidomide (10 mg/day) with or without prednisone.[31-33] In the presence of del(5q), lenalidomide with or without prednisone, can reverse anemia and splenomegaly in most patients.[31-33] However, patients on lenalidomide require prophylaxis for avoiding thrombosis and careful monitoring for hematologic toxicity.
  • Pomalidomide.[34] Patients on pomalidomide require prophylaxis for avoiding thrombosis and careful monitoring for hematologic toxicity.
Ruxolitinib, an inhibitor of JAK1 and JAK2, can reduce the splenomegaly and debilitating symptoms of weight loss, fatigue, and night sweats for patients with JAK2-positive or JAK2-negative primary myelofibrosis, post–essential thrombocythemia myelofibrosis, or post–p. vera myelofibrosis.[35]
In two prospective, randomized trials, 528 higher-risk patients were randomly assigned to ruxolitinib or to either placebo (COMFORT-I [NCT00952289]) or best available therapy (COMFORT-II [NCT00934544]). At 48 weeks, patients on ruxolitinib had a decrease of 30% to 40% in mean spleen volume compared with an increase of 7% to 8% in the control patients.[36][Level of evidence: 1iiDiv]; [37][Level of evidence: 1iDiv] Ruxolitinib also improved overall quality-of-life measures, with low toxic effects in both studies, but with no benefit in overall survival in the initial reports. Additional follow-up in both studies (5 years in COMFORT-I and in COMFORT-II) showed a survival benefit (statistically significant only for COMFORT-I) among ruxolitinib-treated patients compared with control patients (COMFORT-I hazard ratio [HR], 0.69; 95% confidence interval [CI], 0.50–0.96, P = .025; and COMFORT-II HR, 0.67; 95% CI, 0.44–1.02, P = .06).[38,39][Level of evidence: 1iiA] Clinical benefits were observed across a wide variety of clinical subgroups.[40,41] Discontinuation of ruxolitinib results in a rapid worsening of splenomegaly and the recurrence of systemic symptoms.[36,37,42] Ruxolitinib does not reverse bone marrow fibrosis or induce histologic or cytogenetic remissions. Aggressive B-cell lymphomas have occurred among patients treated with ruxolitinib when a preexisting clonal B-cell population was identified at diagnosis in conjunction with myelofibrosis.[43]
Painful splenomegaly can be treated temporarily with ruxolitinib, hydroxyurea, thalidomide, lenalidomide, cladribine, or radiation therapy, but sometimes requires splenectomy.[27,44,45] The decision to perform splenectomy represents a weighing of the benefits (i.e., reduction of symptoms, decreased portal hypertension, and less need for red blood cell transfusions lasting for 1 to 2 years) versus the debits (i.e., postoperative mortality of 10% and morbidity of 30% caused by infection, bleeding, or thrombosis; no benefit for thrombocytopenia; and accelerated progression to the blast-crisis phase that was seen by some investigators but not others).[7,44]
After splenectomy, many physicians use anticoagulation therapy for 4 to 6 weeks to reduce portal vein thrombosis, and hydroxyurea can be utilized to reduce high platelet levels (>1 million).[46] However, data from a retrospective review of 150 patients who underwent surgery provided documentation that 8% of the patients had a thromboembolism and 7% had a major hemorrhage with prior cytoreduction and postoperative subcutaneous heparin used in one half of the patients.[47]
Hydroxyurea is useful in patients with splenomegaly but may have a potential leukemogenic effect.[7] In patients with thrombocytosis and hepatomegaly after splenectomy, cladribine has shown responses as an alternative to hydroxyurea.[48] The use of interferon-alpha can result in hematologic responses, including reduction in spleen size in 30% to 50% of patients, though many patients do not tolerate this medication.[49,50] Favorable responses to thalidomide and lenalidomide have been reported in about 20% to 60% of patients.[25-27,51-53][Level of evidence: 3iiiDiv]
A more aggressive approach involves allogeneic peripheral stem cell or bone marrow transplantation when a suitable donor is available.[54-59] Allogeneic stem cell transplantation is the only potentially curative treatment available, but the associated morbidity and mortality limit its use to younger, high-risk patients.[57,60] Detection of the JAK2 mutation after transplantation is associated with a worse prognosis.[61]
Treatment options include the following:
  1. Ruxolitinib.[36,37,42,62]
  2. Clinical trials involving other JAK2 inhibitors.
  3. Hydroxyurea.[6,7]
  4. Allogeneic peripheral stem cell or bone marrow transplantation.[55-59]
  5. Thalidomide.[25,30,51-54]
  6. Lenalidomide.[27,31-33,53]
  7. Pomalidomide.[34]
  8. Splenectomy.[44,63]
  9. Splenic radiation therapy or radiation to sites of symptomatic extramedullary hematopoiesis (e.g., large lymph nodes, cord compression).[7]
  10. Cladribine.[48]
  11. Interferon-alpha.[49,50]

Current Clinical Trials

Use our advanced clinical trial search to find NCI-supported cancer clinical trials that are now enrolling patients. The search can be narrowed by location of the trial, type of treatment, name of the drug, and other criteria. General information about clinical trials is also available.
References
  1. Hennessy BT, Thomas DA, Giles FJ, et al.: New approaches in the treatment of myelofibrosis. Cancer 103 (1): 32-43, 2005. [PUBMED Abstract]
  2. Campbell PJ, Green AR: The myeloproliferative disorders. N Engl J Med 355 (23): 2452-66, 2006. [PUBMED Abstract]
  3. Cazzola M, Kralovics R: From Janus kinase 2 to calreticulin: the clinically relevant genomic landscape of myeloproliferative neoplasms. Blood 123 (24): 3714-9, 2014. [PUBMED Abstract]
  4. Rumi E, Pietra D, Ferretti V, et al.: JAK2 or CALR mutation status defines subtypes of essential thrombocythemia with substantially different clinical course and outcomes. Blood 123 (10): 1544-51, 2014. [PUBMED Abstract]
  5. Rotunno G, Mannarelli C, Guglielmelli P, et al.: Impact of calreticulin mutations on clinical and hematological phenotype and outcome in essential thrombocythemia. Blood 123 (10): 1552-5, 2014. [PUBMED Abstract]
  6. Barosi G: Myelofibrosis with myeloid metaplasia: diagnostic definition and prognostic classification for clinical studies and treatment guidelines. J Clin Oncol 17 (9): 2954-70, 1999. [PUBMED Abstract]
  7. Tefferi A: Myelofibrosis with myeloid metaplasia. N Engl J Med 342 (17): 1255-65, 2000. [PUBMED Abstract]
  8. Tefferi A, Thiele J, Vardiman JW: The 2008 World Health Organization classification system for myeloproliferative neoplasms: order out of chaos. Cancer 115 (17): 3842-7, 2009. [PUBMED Abstract]
  9. Klampfl T, Gisslinger H, Harutyunyan AS, et al.: Somatic mutations of calreticulin in myeloproliferative neoplasms. N Engl J Med 369 (25): 2379-90, 2013. [PUBMED Abstract]
  10. Nangalia J, Massie CE, Baxter EJ, et al.: Somatic CALR mutations in myeloproliferative neoplasms with nonmutated JAK2. N Engl J Med 369 (25): 2391-405, 2013. [PUBMED Abstract]
  11. Guglielmelli P, Lasho TL, Rotunno G, et al.: The number of prognostically detrimental mutations and prognosis in primary myelofibrosis: an international study of 797 patients. Leukemia 28 (9): 1804-10, 2014. [PUBMED Abstract]
  12. Chim CS, Kwong YL, Lie AK, et al.: Long-term outcome of 231 patients with essential thrombocythemia: prognostic factors for thrombosis, bleeding, myelofibrosis, and leukemia. Arch Intern Med 165 (22): 2651-8, 2005 Dec 12-26. [PUBMED Abstract]
  13. Odenike O: How I treat the blast phase of Philadelphia chromosome-negative myeloproliferative neoplasms. Blood 132 (22): 2339-2350, 2018. [PUBMED Abstract]
  14. Hultcrantz M, Björkholm M, Dickman PW, et al.: Risk for Arterial and Venous Thrombosis in Patients With Myeloproliferative Neoplasms: A Population-Based Cohort Study. Ann Intern Med 168 (5): 317-325, 2018. [PUBMED Abstract]
  15. Hussein K, Pardanani AD, Van Dyke DL, et al.: International Prognostic Scoring System-independent cytogenetic risk categorization in primary myelofibrosis. Blood 115 (3): 496-9, 2010. [PUBMED Abstract]
  16. Cervantes F, Barosi G, Demory JL, et al.: Myelofibrosis with myeloid metaplasia in young individuals: disease characteristics, prognostic factors and identification of risk groups. Br J Haematol 102 (3): 684-90, 1998. [PUBMED Abstract]
  17. Strasser-Weippl K, Steurer M, Kees M, et al.: Age and hemoglobin level emerge as most important clinical prognostic parameters in patients with osteomyelofibrosis: introduction of a simplified prognostic score. Leuk Lymphoma 47 (3): 441-50, 2006. [PUBMED Abstract]
  18. Tefferi A: Survivorship and prognosis in myelofibrosis with myeloid metaplasia. Leuk Lymphoma 47 (3): 379-80, 2006. [PUBMED Abstract]
  19. Tam CS, Kantarjian H, Cortes J, et al.: Dynamic model for predicting death within 12 months in patients with primary or post-polycythemia vera/essential thrombocythemia myelofibrosis. J Clin Oncol 27 (33): 5587-93, 2009. [PUBMED Abstract]
  20. Morel P, Duhamel A, Hivert B, et al.: Identification during the follow-up of time-dependent prognostic factors for the competing risks of death and blast phase in primary myelofibrosis: a study of 172 patients. Blood 115 (22): 4350-5, 2010. [PUBMED Abstract]
  21. Cervantes F, Dupriez B, Pereira A, et al.: New prognostic scoring system for primary myelofibrosis based on a study of the International Working Group for Myelofibrosis Research and Treatment. Blood 113 (13): 2895-901, 2009. [PUBMED Abstract]
  22. Tefferi A, Lasho TL, Jimma T, et al.: One thousand patients with primary myelofibrosis: the mayo clinic experience. Mayo Clin Proc 87 (1): 25-33, 2012. [PUBMED Abstract]
  23. Gangat N, Caramazza D, Vaidya R, et al.: DIPSS plus: a refined Dynamic International Prognostic Scoring System for primary myelofibrosis that incorporates prognostic information from karyotype, platelet count, and transfusion status. J Clin Oncol 29 (4): 392-7, 2011. [PUBMED Abstract]
  24. Caramazza D, Begna KH, Gangat N, et al.: Refined cytogenetic-risk categorization for overall and leukemia-free survival in primary myelofibrosis: a single center study of 433 patients. Leukemia 25 (1): 82-8, 2011. [PUBMED Abstract]
  25. Giovanni B, Michelle E, Letizia C, et al.: Thalidomide in myelofibrosis with myeloid metaplasia: a pooled-analysis of individual patient data from five studies. Leuk Lymphoma 43 (12): 2301-7, 2002. [PUBMED Abstract]
  26. Marchetti M, Barosi G, Balestri F, et al.: Low-dose thalidomide ameliorates cytopenias and splenomegaly in myelofibrosis with myeloid metaplasia: a phase II trial. J Clin Oncol 22 (3): 424-31, 2004. [PUBMED Abstract]
  27. Tefferi A, Cortes J, Verstovsek S, et al.: Lenalidomide therapy in myelofibrosis with myeloid metaplasia. Blood 108 (4): 1158-64, 2006. [PUBMED Abstract]
  28. Cervantes F, Alvarez-Larrán A, Hernández-Boluda JC, et al.: Erythropoietin treatment of the anaemia of myelofibrosis with myeloid metaplasia: results in 20 patients and review of the literature. Br J Haematol 127 (4): 399-403, 2004. [PUBMED Abstract]
  29. Huang J, Tefferi A: Erythropoiesis stimulating agents have limited therapeutic activity in transfusion-dependent patients with primary myelofibrosis regardless of serum erythropoietin level. Eur J Haematol 83 (2): 154-5, 2009. [PUBMED Abstract]
  30. Thomas DA, Giles FJ, Albitar M, et al.: Thalidomide therapy for myelofibrosis with myeloid metaplasia. Cancer 106 (9): 1974-84, 2006. [PUBMED Abstract]
  31. Tefferi A, Lasho TL, Mesa RA, et al.: Lenalidomide therapy in del(5)(q31)-associated myelofibrosis: cytogenetic and JAK2V617F molecular remissions. Leukemia 21 (8): 1827-8, 2007. [PUBMED Abstract]
  32. Mesa RA, Yao X, Cripe LD, et al.: Lenalidomide and prednisone for myelofibrosis: Eastern Cooperative Oncology Group (ECOG) phase 2 trial E4903. Blood 116 (22): 4436-8, 2010. [PUBMED Abstract]
  33. Quintás-Cardama A, Kantarjian HM, Manshouri T, et al.: Lenalidomide plus prednisone results in durable clinical, histopathologic, and molecular responses in patients with myelofibrosis. J Clin Oncol 27 (28): 4760-6, 2009. [PUBMED Abstract]
  34. Begna KH, Mesa RA, Pardanani A, et al.: A phase-2 trial of low-dose pomalidomide in myelofibrosis. Leukemia 25 (2): 301-4, 2011. [PUBMED Abstract]
  35. Verstovsek S, Kantarjian H, Mesa RA, et al.: Safety and efficacy of INCB018424, a JAK1 and JAK2 inhibitor, in myelofibrosis. N Engl J Med 363 (12): 1117-27, 2010. [PUBMED Abstract]
  36. Harrison C, Kiladjian JJ, Al-Ali HK, et al.: JAK inhibition with ruxolitinib versus best available therapy for myelofibrosis. N Engl J Med 366 (9): 787-98, 2012. [PUBMED Abstract]
  37. Verstovsek S, Mesa RA, Gotlib J, et al.: A double-blind, placebo-controlled trial of ruxolitinib for myelofibrosis. N Engl J Med 366 (9): 799-807, 2012. [PUBMED Abstract]
  38. Verstovsek S, Mesa RA, Gotlib J, et al.: Long-term treatment with ruxolitinib for patients with myelofibrosis: 5-year update from the randomized, double-blind, placebo-controlled, phase 3 COMFORT-I trial. J Hematol Oncol 10 (1): 55, 2017. [PUBMED Abstract]
  39. Harrison CN, Vannucchi AM, Kiladjian JJ, et al.: Long-term findings from COMFORT-II, a phase 3 study of ruxolitinib vs best available therapy for myelofibrosis. Leukemia 30 (8): 1701-7, 2016. [PUBMED Abstract]
  40. Mascarenhas J, Hoffman R: A comprehensive review and analysis of the effect of ruxolitinib therapy on the survival of patients with myelofibrosis. Blood 121 (24): 4832-7, 2013. [PUBMED Abstract]
  41. Verstovsek S, Mesa RA, Gotlib J, et al.: The clinical benefit of ruxolitinib across patient subgroups: analysis of a placebo-controlled, Phase III study in patients with myelofibrosis. Br J Haematol 161 (4): 508-16, 2013. [PUBMED Abstract]
  42. Tefferi A, Litzow MR, Pardanani A: Long-term outcome of treatment with ruxolitinib in myelofibrosis. N Engl J Med 365 (15): 1455-7, 2011. [PUBMED Abstract]
  43. Porpaczy E, Tripolt S, Hoelbl-Kovacic A, et al.: Aggressive B-cell lymphomas in patients with myelofibrosis receiving JAK1/2 inhibitor therapy. Blood 132 (7): 694-706, 2018. [PUBMED Abstract]
  44. Barosi G, Ambrosetti A, Centra A, et al.: Splenectomy and risk of blast transformation in myelofibrosis with myeloid metaplasia. Italian Cooperative Study Group on Myeloid with Myeloid Metaplasia. Blood 91 (10): 3630-6, 1998. [PUBMED Abstract]
  45. Lavrenkov K, Krepel-Volsky S, Levi I, et al.: Low dose palliative radiotherapy for splenomegaly in hematologic disorders. Leuk Lymphoma 53 (3): 430-4, 2012. [PUBMED Abstract]
  46. Mesa RA, Nagorney DS, Schwager S, et al.: Palliative goals, patient selection, and perioperative platelet management: outcomes and lessons from 3 decades of splenectomy for myelofibrosis with myeloid metaplasia at the Mayo Clinic. Cancer 107 (2): 361-70, 2006. [PUBMED Abstract]
  47. Ruggeri M, Rodeghiero F, Tosetto A, et al.: Postsurgery outcomes in patients with polycythemia vera and essential thrombocythemia: a retrospective survey. Blood 111 (2): 666-71, 2008. [PUBMED Abstract]
  48. Tefferi A, Mesa RA, Nagorney DM, et al.: Splenectomy in myelofibrosis with myeloid metaplasia: a single-institution experience with 223 patients. Blood 95 (7): 2226-33, 2000. [PUBMED Abstract]
  49. Sacchi S: The role of alpha-interferon in essential thrombocythaemia, polycythaemia vera and myelofibrosis with myeloid metaplasia (MMM): a concise update. Leuk Lymphoma 19 (1-2): 13-20, 1995. [PUBMED Abstract]
  50. Gilbert HS: Long term treatment of myeloproliferative disease with interferon-alpha-2b: feasibility and efficacy. Cancer 83 (6): 1205-13, 1998. [PUBMED Abstract]
  51. Strupp C, Germing U, Scherer A, et al.: Thalidomide for the treatment of idiopathic myelofibrosis. Eur J Haematol 72 (1): 52-7, 2004. [PUBMED Abstract]
  52. Mesa RA, Elliott MA, Schroeder G, et al.: Durable responses to thalidomide-based drug therapy for myelofibrosis with myeloid metaplasia. Mayo Clin Proc 79 (7): 883-9, 2004. [PUBMED Abstract]
  53. Jabbour E, Thomas D, Kantarjian H, et al.: Comparison of thalidomide and lenalidomide as therapy for myelofibrosis. Blood 118 (4): 899-902, 2011. [PUBMED Abstract]
  54. Guardiola P, Anderson JE, Bandini G, et al.: Allogeneic stem cell transplantation for agnogenic myeloid metaplasia: a European Group for Blood and Marrow Transplantation, Société Française de Greffe de Moelle, Gruppo Italiano per il Trapianto del Midollo Osseo, and Fred Hutchinson Cancer Research Center Collaborative Study. Blood 93 (9): 2831-8, 1999. [PUBMED Abstract]
  55. Deeg HJ, Gooley TA, Flowers ME, et al.: Allogeneic hematopoietic stem cell transplantation for myelofibrosis. Blood 102 (12): 3912-8, 2003. [PUBMED Abstract]
  56. Daly A, Song K, Nevill T, et al.: Stem cell transplantation for myelofibrosis: a report from two Canadian centers. Bone Marrow Transplant 32 (1): 35-40, 2003. [PUBMED Abstract]
  57. Gupta V, Hari P, Hoffman R: Allogeneic hematopoietic cell transplantation for myelofibrosis in the era of JAK inhibitors. Blood 120 (7): 1367-79, 2012. [PUBMED Abstract]
  58. Kröger N, Holler E, Kobbe G, et al.: Allogeneic stem cell transplantation after reduced-intensity conditioning in patients with myelofibrosis: a prospective, multicenter study of the Chronic Leukemia Working Party of the European Group for Blood and Marrow Transplantation. Blood 114 (26): 5264-70, 2009. [PUBMED Abstract]
  59. Abelsson J, Merup M, Birgegård G, et al.: The outcome of allo-HSCT for 92 patients with myelofibrosis in the Nordic countries. Bone Marrow Transplant 47 (3): 380-6, 2012. [PUBMED Abstract]
  60. Alchalby H, Yunus DR, Zabelina T, et al.: Risk models predicting survival after reduced-intensity transplantation for myelofibrosis. Br J Haematol 157 (1): 75-85, 2012. [PUBMED Abstract]
  61. Alchalby H, Badbaran A, Zabelina T, et al.: Impact of JAK2V617F mutation status, allele burden, and clearance after allogeneic stem cell transplantation for myelofibrosis. Blood 116 (18): 3572-81, 2010. [PUBMED Abstract]
  62. Verstovsek S: Janus-activated kinase 2 inhibitors: a new era of targeted therapies providing significant clinical benefit for Philadelphia chromosome-negative myeloproliferative neoplasms. J Clin Oncol 29 (7): 781-3, 2011. [PUBMED Abstract]
  63. Tefferi A, Silverstein MN, Li CY: 2-Chlorodeoxyadenosine treatment after splenectomy in patients who have myelofibrosis with myeloid metaplasia. Br J Haematol 99 (2): 352-7, 1997. [PUBMED Abstract]

Essential Thrombocythemia

Disease Overview

The proposed revised World Health Organization (WHO) criteria for the diagnosis of essential thrombocythemia requires the following criteria:[1]
Criteria
  1. Sustained platelet count of at least 450 × 109/L.
  2. Bone marrow biopsy showing predominant proliferation of enlarged mature megakaryocytes; no significant increase of granulocytic or erythroid precursors. This finding distinguishes essential thrombocythemia from another entity with thrombocytosis, namely prefibrotic primary myelofibrosis, which is identified by increased granulocytic or erythroid precursors, atypical megakaryocytes, and increased bone marrow cellularity.
    Patients with prefibrotic primary myelofibrosis have a worse survival than patients with essential thrombocythemia because of an increased progression to myelofibrosis and increased progression to acute myelogenous leukemia.[2-4] Patients with prefibrotic primary myelofibrosis may also have a higher tendency to bleed, which can be exacerbated by low-dose aspirin.[5]
  3. Not meeting criteria for polycythemia vera (p. vera), primary myelofibrosis, chronic myelogenous leukemia, myelodysplastic syndrome, or other myeloid neoplasm.
  4. Demonstration of JAK2 V617F mutation or myeloproliferative leukemia (MPL) exon 10 mutation.[6] In the absence of a clonal marker, there must be no evidence for reactive thrombocytosis. In particular, with a decreased serum ferritin, there must be no increase in hemoglobin level to p. vera range with iron replacement therapy. In the presence of a JAK2 or MPL mutation and exclusion of other myeloproliferative or myelodysplastic features, a bone marrow aspirate/biopsy may not be mandatory for a diagnosis.[7] About 60% of patients with essential thrombocythemia carry a JAK2mutation, and about 5% to 10% of the patients have activating mutations in the thrombopoietin receptor gene, MPL. About 70% of the patients without JAK2 or MPLcarry a somatic mutation of the CALR gene, which is associated with a more indolent clinical course than is seen with JAK2 or MPL mutations.[8-12]
Patients older than 60 years or those with a previous thrombotic episode or with leukocytosis have as much as a 25% chance of developing cerebral, cardiac, or peripheral arterial thromboses and, less often, a chance of developing a pulmonary embolism or deep venous thrombosis.[2,13-15] Similar to the other myeloproliferative syndromes, conversion to acute leukemia is found in a small percentage of patients (<10%) with long-term follow-up.
There is no staging system for this disease.
Untreated essential thrombocythemia means that a patient is newly diagnosed and has had no previous treatment except supportive care.

Treatment Overview

Controversy is considerable regarding whether asymptomatic patients with essential thrombocythemia require treatment.[16] In a case-controlled, observational study of 65 low-risk patients (age <60 years, platelet count <1,500 × 109/L, and no history of thrombosis or hemorrhage) with a median follow-up of 4.1 years, the thrombotic risk of 1.91 cases per 100 patient years and hemorrhagic risk of 1.12 cases per 100 patient years was not increased any more than in the normal controls.[17]
  1. A prospective randomized trial of 382 patients aged 40 to 59 years with essential thrombocythemia and with good risk factors (no history of thrombosis or bleeding, no hypertension, no diabetes, platelet count ≤ 1,500 × 109/L) were randomly assigned to receive aspirin alone versus hydroxyurea plus aspirin.[18]
    • After a median follow-up of 73 months, there was no difference in thrombosis, hemorrhage, or survival (hazard ratio [HR], 0.98; 95% confidence interval [CI], 0.42‒2.25; P = 1.0).[18][Level of evidence: 1iiD] Patients younger than 60 years who lacked high-risk factors did not benefit from the addition of hydroxyurea to aspirin.
  2. A randomized trial of patients with essential thrombocythemia and a high risk of thrombosis compared treatment with hydroxyurea titrated to attain a platelet count below 600,000/mm3 with a control group that received no therapy. Hydroxyurea was found to be effective in preventing thrombotic episodes (4% vs. 24%).[13][Level of evidence: 1iiDiv]
    • A retrospective analysis of this trial found that antiplatelet drugs had no significant influence on the outcome. Resistance to hydroxyurea is defined as a platelet count of greater than 600,000/μL after 3 months of at least 2 g per day of hydroxyurea or a platelet count greater than 400,000/µL and a white blood count of less than 2,500/µL or a hemoglobin less than 10 g/dL at any dose of hydroxyurea.[19]
  3. A prospective randomized trial in the United Kingdom (UK) of 809 patients compared hydroxyurea plus aspirin with anagrelide plus aspirin.[20]
    • Although the platelet-lowering effect was equivalent, the anagrelide group had significantly more thrombotic and hemorrhagic events (HR, 1.57; P = .03) and more myelofibrosis (HR, 2.92; P = .01).
    • No differences were seen for subsequent myelodysplasia or acute leukemia in this trial.[21][Level of evidence: 1iiD]
  4. Another prospective randomized trial also compared hydroxyurea and anagrelide in 259 previously untreated and high-risk patients.[22] In this central European trial, the diagnosis of essential thrombocythemia was made by the WHO recommendations, not by the Polycythemia Vera Study Group criteria as in the UK study. This means that patients with leukocytosis and a diagnosis of early prefibrotic myelofibrosis (both groups with much higher rates of thrombosis) were excluded from the central European trial.
These randomized prospective trials establish the efficacy and safety for the use of hydroxyurea for patients with high-risk essential thrombocythemia (age >60 years + platelet count >1,000 × 109/L or >1,500 × 109/L). For patients diagnosed by WHO standards (excluding patients with leukocytosis and prefibrotic myelofibrosis by bone marrow biopsy), anagrelide represents a reasonable alternative therapy. The addition of aspirin to cytoreductive therapies like hydroxyurea or anagrelide remains controversial, but a retrospective anecdotal report suggested reduction in thrombosis for patients older than 60 years.[23] Unlike results for p. vera or myelofibrosis, ruxolitinib was not helpful for patients resistant to hydroxyurea.[24]
Many clinicians use hydroxyurea or platelet apheresis prior to elective surgery to reduce the platelet count and to prevent postoperative thromboembolism. No prospective or randomized trials document the value of this approach.
Among low-risk patients (defined as age ≤60 years with no prior thrombotic episodes), a retrospective review of 300 patients showed benefit for antiplatelet agents in reducing venous thrombosis in JAK2-positive cases and in reducing arterial thrombosis in patients with cardiovascular risk factors.[25] Balancing the risks and benefits of aspirin for low-risk patients can be difficult.[26] In an extrapolation of the data from trials of p. vera, low-dose aspirin to prevent vascular events has been suggested, but there are no data from clinical trials to address this issue.[27,28]
Treatment options include the following:
  1. No treatment, unless complications develop, if patients are asymptomatic, younger than 60 years, and have a platelet count of less than 1,500 × 109/L.
  2. Hydroxyurea.[13]
  3. Interferon-alpha [29-32] or pegylated interferon-alpha.[33,34]
  4. Anagrelide.[21,35]

Current Clinical Trials

Use our advanced clinical trial search to find NCI-supported cancer clinical trials that are now enrolling patients. The search can be narrowed by location of the trial, type of treatment, name of the drug, and other criteria. General information about clinical trials is also available.
References
  1. Tefferi A, Thiele J, Vardiman JW: The 2008 World Health Organization classification system for myeloproliferative neoplasms: order out of chaos. Cancer 115 (17): 3842-7, 2009. [PUBMED Abstract]
  2. Passamonti F, Thiele J, Girodon F, et al.: A prognostic model to predict survival in 867 World Health Organization-defined essential thrombocythemia at diagnosis: a study by the International Working Group on Myelofibrosis Research and Treatment. Blood 120 (6): 1197-201, 2012. [PUBMED Abstract]
  3. Barbui T, Thiele J, Carobbio A, et al.: Disease characteristics and clinical outcome in young adults with essential thrombocythemia versus early/prefibrotic primary myelofibrosis. Blood 120 (3): 569-71, 2012. [PUBMED Abstract]
  4. Barbui T, Thiele J, Passamonti F, et al.: Survival and disease progression in essential thrombocythemia are significantly influenced by accurate morphologic diagnosis: an international study. J Clin Oncol 29 (23): 3179-84, 2011. [PUBMED Abstract]
  5. Finazzi G, Carobbio A, Thiele J, et al.: Incidence and risk factors for bleeding in 1104 patients with essential thrombocythemia or prefibrotic myelofibrosis diagnosed according to the 2008 WHO criteria. Leukemia 26 (4): 716-9, 2012. [PUBMED Abstract]
  6. Campbell PJ, Green AR: The myeloproliferative disorders. N Engl J Med 355 (23): 2452-66, 2006. [PUBMED Abstract]
  7. Harrison CN, Bareford D, Butt N, et al.: Guideline for investigation and management of adults and children presenting with a thrombocytosis. Br J Haematol 149 (3): 352-75, 2010. [PUBMED Abstract]
  8. Klampfl T, Gisslinger H, Harutyunyan AS, et al.: Somatic mutations of calreticulin in myeloproliferative neoplasms. N Engl J Med 369 (25): 2379-90, 2013. [PUBMED Abstract]
  9. Nangalia J, Massie CE, Baxter EJ, et al.: Somatic CALR mutations in myeloproliferative neoplasms with nonmutated JAK2. N Engl J Med 369 (25): 2391-405, 2013. [PUBMED Abstract]
  10. Cazzola M, Kralovics R: From Janus kinase 2 to calreticulin: the clinically relevant genomic landscape of myeloproliferative neoplasms. Blood 123 (24): 3714-9, 2014. [PUBMED Abstract]
  11. Rumi E, Pietra D, Ferretti V, et al.: JAK2 or CALR mutation status defines subtypes of essential thrombocythemia with substantially different clinical course and outcomes. Blood 123 (10): 1544-51, 2014. [PUBMED Abstract]
  12. Rotunno G, Mannarelli C, Guglielmelli P, et al.: Impact of calreticulin mutations on clinical and hematological phenotype and outcome in essential thrombocythemia. Blood 123 (10): 1552-5, 2014. [PUBMED Abstract]
  13. Cortelazzo S, Finazzi G, Ruggeri M, et al.: Hydroxyurea for patients with essential thrombocythemia and a high risk of thrombosis. N Engl J Med 332 (17): 1132-6, 1995. [PUBMED Abstract]
  14. Harrison C, Kiladjian JJ, Al-Ali HK, et al.: JAK inhibition with ruxolitinib versus best available therapy for myelofibrosis. N Engl J Med 366 (9): 787-98, 2012. [PUBMED Abstract]
  15. Hultcrantz M, Björkholm M, Dickman PW, et al.: Risk for Arterial and Venous Thrombosis in Patients With Myeloproliferative Neoplasms: A Population-Based Cohort Study. Ann Intern Med 168 (5): 317-325, 2018. [PUBMED Abstract]
  16. Masarova L, Verstovsek S: Therapeutic Approach to Young Patients With Low-Risk Essential Thrombocythemia: Primum Non Nocere. J Clin Oncol : JCO2018793497, 2018. [PUBMED Abstract]
  17. Ruggeri M, Finazzi G, Tosetto A, et al.: No treatment for low-risk thrombocythaemia: results from a prospective study. Br J Haematol 103 (3): 772-7, 1998. [PUBMED Abstract]
  18. Godfrey AL, Campbell PJ, MacLean C, et al.: Hydroxycarbamide Plus Aspirin Versus Aspirin Alone in Patients With Essential Thrombocythemia Age 40 to 59 Years Without High-Risk Features. J Clin Oncol : JCO2018788414, 2018. [PUBMED Abstract]
  19. Barosi G, Besses C, Birgegard G, et al.: A unified definition of clinical resistance/intolerance to hydroxyurea in essential thrombocythemia: results of a consensus process by an international working group. Leukemia 21 (2): 277-80, 2007. [PUBMED Abstract]
  20. Harrison CN, Campbell PJ, Buck G, et al.: Hydroxyurea compared with anagrelide in high-risk essential thrombocythemia. N Engl J Med 353 (1): 33-45, 2005. [PUBMED Abstract]
  21. Green A, Campbell P, Buck G: The Medical Research Council PT1 trial in essential thrombocythemia. [Abstract] Blood 104 (11): A-6, 2004.
  22. Gisslinger H, Gotic M, Holowiecki J, et al.: Anagrelide compared with hydroxyurea in WHO-classified essential thrombocythemia: the ANAHYDRET Study, a randomized controlled trial. Blood 121 (10): 1720-8, 2013. [PUBMED Abstract]
  23. Alvarez-Larrán A, Pereira A, Arellano-Rodrigo E, et al.: Cytoreduction plus low-dose aspirin versus cytoreduction alone as primary prophylaxis of thrombosis in patients with high-risk essential thrombocythaemia: an observational study. Br J Haematol 161 (6): 865-71, 2013. [PUBMED Abstract]
  24. Harrison CN, Mead AJ, Panchal A, et al.: Ruxolitinib vs best available therapy for ET intolerant or resistant to hydroxycarbamide. Blood 130 (17): 1889-1897, 2017. [PUBMED Abstract]
  25. Alvarez-Larrán A, Cervantes F, Pereira A, et al.: Observation versus antiplatelet therapy as primary prophylaxis for thrombosis in low-risk essential thrombocythemia. Blood 116 (8): 1205-10; quiz 1387, 2010. [PUBMED Abstract]
  26. Harrison C, Barbui T: Aspirin in low-risk essential thrombocythemia, not so simple after all? Leuk Res 35 (3): 286-9, 2011. [PUBMED Abstract]
  27. Finazzi G: How to manage essential thrombocythemia. Leukemia 26 (5): 875-82, 2012. [PUBMED Abstract]
  28. Squizzato A, Romualdi E, Passamonti F, et al.: Antiplatelet drugs for polycythaemia vera and essential thrombocythaemia. Cochrane Database Syst Rev 4: CD006503, 2013. [PUBMED Abstract]
  29. Sacchi S: The role of alpha-interferon in essential thrombocythaemia, polycythaemia vera and myelofibrosis with myeloid metaplasia (MMM): a concise update. Leuk Lymphoma 19 (1-2): 13-20, 1995. [PUBMED Abstract]
  30. Gilbert HS: Long term treatment of myeloproliferative disease with interferon-alpha-2b: feasibility and efficacy. Cancer 83 (6): 1205-13, 1998. [PUBMED Abstract]
  31. Huang BT, Zeng QC, Zhao WH, et al.: Interferon α-2b gains high sustained response therapy for advanced essential thrombocythemia and polycythemia vera with JAK2V617F positive mutation. Leuk Res 38 (10): 1177-83, 2014. [PUBMED Abstract]
  32. Masarova L, Patel KP, Newberry KJ, et al.: Pegylated interferon alfa-2a in patients with essential thrombocythaemia or polycythaemia vera: a post-hoc, median 83 month follow-up of an open-label, phase 2 trial. Lancet Haematol 4 (4): e165-e175, 2017. [PUBMED Abstract]
  33. Quintás-Cardama A, Kantarjian H, Manshouri T, et al.: Pegylated interferon alfa-2a yields high rates of hematologic and molecular response in patients with advanced essential thrombocythemia and polycythemia vera. J Clin Oncol 27 (32): 5418-24, 2009. [PUBMED Abstract]
  34. Quintás-Cardama A, Abdel-Wahab O, Manshouri T, et al.: Molecular analysis of patients with polycythemia vera or essential thrombocythemia receiving pegylated interferon α-2a. Blood 122 (6): 893-901, 2013. [PUBMED Abstract]
  35. Anagrelide, a therapy for thrombocythemic states: experience in 577 patients. Anagrelide Study Group. Am J Med 92 (1): 69-76, 1992. [PUBMED Abstract]

Chronic Neutrophilic Leukemia (CNL)

Disease Overview

CNL is a rare chronic myeloproliferative neoplasm of unknown etiology, characterized by sustained peripheral blood neutrophilia (>25 × 109/L) and hepatosplenomegaly.[1,2] The bone marrow is hypercellular. No significant dysplasia is in any of the cell lineages, and bone marrow fibrosis is uncommon.[1,2] Cytogenetic studies are normal in nearly 90% of the patients. In the remaining patients, clonal karyotypic abnormalities may include +8, +9, del (20q) and del (11q).[1,3-5] There is no Philadelphia chromosome or BCR/ABL fusion gene. CNL is a slowly progressive disorder, and the survival of patients is variable, ranging from 6 months to more than 20 years.

Treatment Overview

Until the last few years, the treatment of CNL focused on disease control rather than cure. Once the disease progressed to a more aggressive leukemia, there was typically little chance of obtaining a long-lasting remission because of the older age of most patients as well as the acquisition of multiple poor prognostic cytogenetic abnormalities. Allogeneic bone marrow transplantation represents a potentially curative treatment modality in the management of this disorder.[6-8] Varying success has been reported with the use of traditional chemotherapies including hydroxyurea and interferon.[9]

Current Clinical Trials

Use our advanced clinical trial search to find NCI-supported cancer clinical trials that are now enrolling patients. The search can be narrowed by location of the trial, type of treatment, name of the drug, and other criteria. General information about clinical trials is also available.
References
  1. Imbert M, Bain B, Pierre R, et al.: Chronic neutrophilic leukemia. In: Jaffe ES, Harris NL, Stein H, et al., eds.: Pathology and Genetics of Tumours of Haematopoietic and Lymphoid Tissues. Lyon, France: IARC Press, 2001. World Health Organization Classification of Tumours, 3, pp 27-8.
  2. Zittoun R, Réa D, Ngoc LH, et al.: Chronic neutrophilic leukemia. A study of four cases. Ann Hematol 68 (2): 55-60, 1994. [PUBMED Abstract]
  3. Froberg MK, Brunning RD, Dorion P, et al.: Demonstration of clonality in neutrophils using FISH in a case of chronic neutrophilic leukemia. Leukemia 12 (4): 623-6, 1998. [PUBMED Abstract]
  4. Yanagisawa K, Ohminami H, Sato M, et al.: Neoplastic involvement of granulocytic lineage, not granulocytic-monocytic, monocytic, or erythrocytic lineage, in a patient with chronic neutrophilic leukemia. Am J Hematol 57 (3): 221-4, 1998. [PUBMED Abstract]
  5. Matano S, Nakamura S, Kobayashi K, et al.: Deletion of the long arm of chromosome 20 in a patient with chronic neutrophilic leukemia: cytogenetic findings in chronic neutrophilic leukemia. Am J Hematol 54 (1): 72-5, 1997. [PUBMED Abstract]
  6. Piliotis E, Kutas G, Lipton JH: Allogeneic bone marrow transplantation in the management of chronic neutrophilic leukemia. Leuk Lymphoma 43 (10): 2051-4, 2002. [PUBMED Abstract]
  7. Hasle H, Olesen G, Kerndrup G, et al.: Chronic neutrophil leukaemia in adolescence and young adulthood. Br J Haematol 94 (4): 628-30, 1996. [PUBMED Abstract]
  8. Böhm J, Schaefer HE: Chronic neutrophilic leukaemia: 14 new cases of an uncommon myeloproliferative disease. J Clin Pathol 55 (11): 862-4, 2002. [PUBMED Abstract]
  9. Elliott MA, Dewald GW, Tefferi A, et al.: Chronic neutrophilic leukemia (CNL): a clinical, pathologic and cytogenetic study. Leukemia 15 (1): 35-40, 2001. [PUBMED Abstract]

Chronic Eosinophilic Leukemia (CEL)

Disease Overview

CEL is a chronic myeloproliferative neoplasm of unknown etiology in which a clonal proliferation of eosinophilic precursors results in persistently increased numbers of eosinophils in the blood, bone marrow, and peripheral tissues. In CEL, the eosinophil count is greater than or equal to 1.5 × 109/L in the blood.[1] To make a diagnosis of CEL, there should be evidence for clonality of the eosinophils or an increase in blasts in the blood or bone marrow. In many cases, however, it is impossible to prove clonality of the eosinophils, in which case, if there is no increase in blast cells, the diagnosis of idiopathic hypereosinophilic syndrome (HES) is preferred. Because of the difficulty in distinguishing CEL from HES, the true incidence of these diseases is unknown, although they are rare. In about 10% of patients, eosinophilia is detected incidentally. In others, the constitutional symptoms found include the following:[1,2]
  • Fever.
  • Fatigue.
  • Cough.
  • Angioedema.
  • Muscle pains.
  • Pruritus.
  • Diarrhea.
No single or specific cytogenetic or molecular genetic abnormality has been identified in CEL.
(Refer to the PDQ summaries on Hot Flashes and Night Sweats; Fatigue; Cardiopulmonary Syndromes; Cancer Pain; Pruritus; and Gastrointestinal Complications for information on many of the symptoms listed above.)

Treatment Overview

The optimal treatment of CEL remains uncertain, partially on account of the rare incidence of this chronic myeloproliferative neoplasm and the variable clinical course, which can range from cases with decades of stable disease to cases with rapid progression to acute leukemia. Case reports suggest that treatment options include bone marrow transplantation and interferon-alpha.[3,4]
Treatment of HES has included the following:[5,6]
  • Corticosteroids.
  • Chemotherapeutic agents such as hydroxyurea, cyclophosphamide, and vincristine.
  • Interferon-alpha.
Case reports suggest symptomatic responses to imatinib mesylate for patients with HES who have not responded to conventional options.[6-8][Level of evidence: 3iiiDiv] Imatinib mesylate acts as an inhibitor of a novel fusion tyrosine kinase, FIP1L1-PDGFR alpha fusion tyrosine kinase, which results as a consequence of interstitial chromosomal deletion.[6,9][Level of evidence: 3iiiDiv] HES with the FIP1L1-PDGFR alpha fusion tyrosine kinase translocation has been shown to respond to low-dose imatinib mesylate.[9]

Current Clinical Trials

Use our advanced clinical trial search to find NCI-supported cancer clinical trials that are now enrolling patients. The search can be narrowed by location of the trial, type of treatment, name of the drug, and other criteria. General information about clinical trials is also available.
References
  1. Bain B, Pierre P, Imbert M, et al.: Chronic eosinophillic leukaemia and the hypereosinophillic syndrome. In: Jaffe ES, Harris NL, Stein H, et al., eds.: Pathology and Genetics of Tumours of Haematopoietic and Lymphoid Tissues. Lyon, France: IARC Press, 2001. World Health Organization Classification of Tumours, 3, pp 29-31.
  2. Weller PF, Bubley GJ: The idiopathic hypereosinophilic syndrome. Blood 83 (10): 2759-79, 1994. [PUBMED Abstract]
  3. Basara N, Markova J, Schmetzer B, et al.: Chronic eosinophilic leukemia: successful treatment with an unrelated bone marrow transplantation. Leuk Lymphoma 32 (1-2): 189-93, 1998. [PUBMED Abstract]
  4. Yamada O, Kitahara K, Imamura K, et al.: Clinical and cytogenetic remission induced by interferon-alpha in a patient with chronic eosinophilic leukemia associated with a unique t(3;9;5) translocation. Am J Hematol 58 (2): 137-41, 1998. [PUBMED Abstract]
  5. Butterfield JH, Gleich GJ: Interferon-alpha treatment of six patients with the idiopathic hypereosinophilic syndrome. Ann Intern Med 121 (9): 648-53, 1994. [PUBMED Abstract]
  6. Gotlib J, Cools J, Malone JM 3rd, et al.: The FIP1L1-PDGFRalpha fusion tyrosine kinase in hypereosinophilic syndrome and chronic eosinophilic leukemia: implications for diagnosis, classification, and management. Blood 103 (8): 2879-91, 2004. [PUBMED Abstract]
  7. Gleich GJ, Leiferman KM, Pardanani A, et al.: Treatment of hypereosinophilic syndrome with imatinib mesilate. Lancet 359 (9317): 1577-8, 2002. [PUBMED Abstract]
  8. Ault P, Cortes J, Koller C, et al.: Response of idiopathic hypereosinophilic syndrome to treatment with imatinib mesylate. Leuk Res 26 (9): 881-4, 2002. [PUBMED Abstract]
  9. Cools J, DeAngelo DJ, Gotlib J, et al.: A tyrosine kinase created by fusion of the PDGFRA and FIP1L1 genes as a therapeutic target of imatinib in idiopathic hypereosinophilic syndrome. N Engl J Med 348 (13): 1201-14, 2003. [PUBMED Abstract]

Changes to This Summary (04/18/2019)

The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.
General Information About Chronic Myeloproliferative Neoplasms (MPN)
Added Hultcrantz et al. as reference 1.
Revised text to state that researchers are pursuing specific targeting of this aberrant protein as well as new targets based on next-generation sequencing of the genome (cited Grinfeld et al. as reference 12).
Added text to state that leukemic transformation from Philadelphia chromosome‒negative myeloproliferative neoplasms is defined as having 20% or greater myeloblasts in the blood or marrow and having no standard approach and a poor prognosis (cited Mascarenhas et al. as reference 16). Also added that allogeneic stem cell transplantation has resulted in anecdotal long-term survivors, but this approach is often not feasible in older patients with comorbid conditions or lack of initial response to leukemic induction therapy (cited Alchalby et al. as reference 17).
Chronic Myelogenous Leukemia
Added Hultcrantz et al. as reference 5.
Added 2017 Masarova et al. as reference 17.
Added text to state that patients with polycythemia vera and no splenomegaly in whom hydroxyurea failed were studied in a randomized prospective trial of 173 participants; patients were randomly assigned to receive ruxolitinib or the best available therapy. Hematocrit control was achieved in 62% of ruxolitinib-treated patients versus 19% of controls (cited Passamonti et al. as reference 19 and level of evidence 1iiDiv).
Primary Myelofibrosis
Added Odenike et al. as reference 13.
Added Hultcrantz et al. as reference 14.
Revised text to state that additional follow-up in both studies (5 years in COMFORT-I and COMFORT-II) showed a survival benefit (statistically significant only for COMFORT-I) among ruxolitinib-treated patients compared with control patients (cited Verstovsek et al. as reference 38 and 2016 Harrison et al. as reference 39). Added that aggressive B-cell lymphomas have occurred among patients treated with ruxolitinib when a preexisting clonal B-cell population was identified at diagnosis in conjunction with myelofibrosis (cited Porpaczy et al. as reference 43).
Essential Thrombocythemia
Added Hultcrantz et al. as reference 15.
Added 2018 Masarova et al. as reference 16.
Added text to state that a prospective randomized trial of 382 patients aged 40 to 59 years with essential thrombocythemia and with good risk factors were randomly assigned to receive aspirin alone or hydroxyurea plus aspirin; after a median follow-up of 73 months, there was no difference in thrombosis, hemorrhage, or survival, and patients younger than 60 years who lacked high-risk factors did not benefit from the addition of hydroxyurea to aspirin (cited Godfrey et al. as reference 18 and level of evidence 1iiD).
Added text to state that unlike results for p. vera or myelofibrosis, ruxolitinib was not helpful for patients resistant to hydroxyurea (cited 2017 Harrison et al. as reference 24).
This summary is written and maintained by the PDQ Adult Treatment Editorial Board, which is editorially independent of NCI. The summary reflects an independent review of the literature and does not represent a policy statement of NCI or NIH. More information about summary policies and the role of the PDQ Editorial Boards in maintaining the PDQ summaries can be found on the About This PDQ Summary and PDQ® - NCI's Comprehensive Cancer Database pages.

About This PDQ Summary

Purpose of This Summary

This PDQ cancer information summary for health professionals provides comprehensive, peer-reviewed, evidence-based information about the treatment of chronic myeloproliferative neoplasms. It is intended as a resource to inform and assist clinicians who care for cancer patients. It does not provide formal guidelines or recommendations for making health care decisions.

Reviewers and Updates

This summary is reviewed regularly and updated as necessary by the PDQ Adult Treatment Editorial Board, which is editorially independent of the National Cancer Institute (NCI). The summary reflects an independent review of the literature and does not represent a policy statement of NCI or the National Institutes of Health (NIH).
Board members review recently published articles each month to determine whether an article should:
  • be discussed at a meeting,
  • be cited with text, or
  • replace or update an existing article that is already cited.
Changes to the summaries are made through a consensus process in which Board members evaluate the strength of the evidence in the published articles and determine how the article should be included in the summary.
The lead reviewers for Chronic Myeloproliferative Neoplasms Treatment are:
  • Eric J. Seifter, MD (Johns Hopkins University)
  • Mikkael A. Sekeres, MD, MS (Cleveland Clinic Taussig Cancer Institute)
Any comments or questions about the summary content should be submitted to Cancer.gov through the NCI website's Email Us. Do not contact the individual Board Members with questions or comments about the summaries. Board members will not respond to individual inquiries.

Levels of Evidence

Some of the reference citations in this summary are accompanied by a level-of-evidence designation. These designations are intended to help readers assess the strength of the evidence supporting the use of specific interventions or approaches. The PDQ Adult Treatment Editorial Board uses a formal evidence ranking system in developing its level-of-evidence designations.

Permission to Use This Summary

PDQ is a registered trademark. Although the content of PDQ documents can be used freely as text, it cannot be identified as an NCI PDQ cancer information summary unless it is presented in its entirety and is regularly updated. However, an author would be permitted to write a sentence such as “NCI’s PDQ cancer information summary about breast cancer prevention states the risks succinctly: [include excerpt from the summary].”
The preferred citation for this PDQ summary is:
PDQ® Adult Treatment Editorial Board. PDQ Chronic Myeloproliferative Neoplasms Treatment. Bethesda, MD: National Cancer Institute. Updated <MM/DD/YYYY>. Available at: https://www.cancer.gov/types/myeloproliferative/hp/chronic-treatment-pdq. Accessed <MM/DD/YYYY>. [PMID: 26389291]
Images in this summary are used with permission of the author(s), artist, and/or publisher for use within the PDQ summaries only. Permission to use images outside the context of PDQ information must be obtained from the owner(s) and cannot be granted by the National Cancer Institute. Information about using the illustrations in this summary, along with many other cancer-related images, is available in Visuals Online, a collection of over 2,000 scientific images.

Disclaimer

Based on the strength of the available evidence, treatment options may be described as either “standard” or “under clinical evaluation.” These classifications should not be used as a basis for insurance reimbursement determinations. More information on insurance coverage is available on Cancer.gov on the Managing Cancer Care page.

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  • Updated: April 18, 2019
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