To Treat or Not to Treat: A Novel Stratification of Myelofibrosis Patients by Likelihood of Response to JAK2 Inhibitors

Abstract

Objectives: It has been suggested in recent publications that there is a higher incidence of lymphoid malignancies (LM) in patients with myeloproliferative neoplasms (MPN). We report the prevalence of LM in patients with MPN seen at our institution, their clinical characteristics and outcome. Methods: We performed a retrospective chart review of all pts with MPN evaluated at MD Anderson Cancer Center between 1966 and 2013 (N1⁄42647) for evidence of LM. In identified patients with both MPN and LM, we recorded the pathologically-confirmed diagnosis of LM, and analyzed their characteristics, treatment received, and overall outcome, using descriptive statistics. Results: A total of 24 patients with history of both MPN and LM were identified: half were male, 79% white. In 15 patients LM was diagnosed before MPN, with median of 74 months between the two diagnoses (range 2-215), and in 9 LM was diagnosed after MPN, with a median time between the two diagnoses of 97 months (range 2-438). Half of the patients are currently alive, with median follow up of 45 months from initial visit (0-149), 50 months (0-272) from diagnosis of first malignancy. Most common MPN diagnosis among 8 represented subtypes was myelofibrosis (MF) (11 patients, 45%); however, this reflected predominance of MF among our MPN patients (47% of all MPNs). Other types included essential thrombocythemia, polycythemia Vera, mastocytosis, hyper eosinophilic syndrome, Phchronic myeloid leukemia, MPN/myelodysplasic syndrome, and unclassifiable MPN. MPN disease characteristics included: splenomegaly in 42%, abnormal karyotype in 29%, JAK2 mutation in 38%, transformation to acute leukemia in one patient. History of LM did not affect the overall outcome of MPN. LM included 17 lymphoma, 4 myeloma, and 3 Hodgkin’s disease patients that were equally distributed among 8 differentMPN subtypes. Twenty one patients received standard therapy for their type of LM (3unknown) and achieved expectedoverall response; presence orhistory ofMPN did not influence choice of therapy or outcome.Conclusions: In our experience, presence of LM in patients with MPN is very rare event. Presence or history of MPN should not affect the choice of therapy for LM, since it does not have an influence on the outcome.