(All the articles published in past are available at www.shyamhemoncclinic.com/blog/)
Question: Dr. Chiragbhai, thank you very much for helping us summarize this complex topic. In last part we covered myelodysplastic syndrome. Low grade MDS can be managed conservatively for many years. But high grade MDS has a short survival and only curative option is transplant, now feasible even in much older patients. New options like azacytidine and decitabine provide relief in many, but short term. BEFORE WE PROCEED, LET ME CONGRATULATE YOU FOR YOUR BOOK ON CANCER AWARENESS in GUJARATI language, covering Blood, Breast, Gastrointestinal cancers. For our readers, it is available through publisher at 7926620472/09879500179.
Ans: Let us continue our discussion to cover Myeloproliferative syndrome treatment advances. It is now referred to as Myeloproliferative Neoplasms i.e. MPN to convey the malignant nature of these disorders. Most of these however are fairly low grade and frequently do not shorten life span substantially. But it has many subtypes and variable prognosis. CML has been covered earlier.
Polycythemia vera: Best treatment for PV is PHLEBOTOMY. This is the simplest, safest and still considered the best therapy. Goal is to keep Hct below 45. Initially more frequent phlebotomy is required, but later generally every 2-3 months is sufficient. Iron rich diet is to be avoided. Low dose Aspirin is given to all patients, however benefit is small and somewhat controversial. Higher dose aspirin should be avoided as there is risk of increased bleeding in these patients. Hydroxyurea is used for high risk patients defined as age >60 or those with a history of thrombosis. Optimal platelet count is not known. Patients with thrombosis are treated with hydroxyurea to keep platelet count near normal.
Essential Thrombocytosis: Similar to polycythemia vera, patients older than 60 or history of thrombosis are given hydroxyurea and aspirin. All other patients receive only aspirin. Interestingly, for younger patients with no history of thrombosis and no cardiovascular risk factors, platelet reduction is not required up to even 1,500,000. There are studies to suggest, however, that patients with JAK 2 mutation are at higher risk of thrombosis, and should probably be treated to keep platelets near normal. Most of the studies do not show a correlation between platelet count and risk of thrombosis, but correlation with wbc count, Hb etc. Management of pregnancy and perioperative is same as polycythemia largely.
Myelofibrosis: MF still remains a difficult disease to treat. Only curative treatment is Allogeneic Stem Cell Transplant. Transplant results have improved. New treatment is Ruxolitinib, a JAK 1/JAK 2 inhibitor. This oral drug works slowly, but reduces spleen size and improves symptoms of fever/fatigue/weight loss/pruritus in over 50% patients. However surprisingly it does not improve anemia, which responds better to thalidomide and prednisone. Splenectomy is reserved for palliation of significant pain. It has higher surgical morbidity and mortality than in general population due to platelet dysfunction. Everolimus is another new drug with small series reported.
Eosinophilia: Eosinophilia has many causes, but some patients have myeloproliferative type of eosinophilia. These patients frequently respond to imatinib (as in CML), especially if they have PDGFRA or PDGFRB positivity. Such patients generally need very low doses of imatinib. Others may respond to hydroxyurea or steroids. Mepolizumab is a new agent, approved for Churg Strauss syndrome, but sometimes used for other difficult eosinophilia. Allogeneic stem cell transplant is reserved for refractory eosinophilia.
MPNs otherwise unspecified: There are several patients who do not fit any of the standard category of MPN but exhibit common features. They are treated generally by hydroxyurea, and in resistant cases by melphalan, busulfan etc. They have variable prognosis. Some of them have an overlap syndrome with even MDS, where one or two of the cell lines may actually be low.
November 9th, 2014.
Dr. Chirag A. Shah; M.D. Oncology/Hematology (USA), 079 26754001. Diplomate American Board of Oncology and Hematology. Ahmedabad. firstname.lastname@example.org Shyam Hem-Onc Clinic. 402 Galaxy, Near Shivranjani, Opp Jhansi ki Rani BRTS, Ahmedabad. www.shyamhemoncclinic.com