Characteristics and outcomes of Philadelphia chromosome-negative myeloproliferative neoplasm in a tertiary institute in India: An ambispective study.

Abstract

e18553 Background: Philadelphia chromosome (Ph) negative Myeloproliferative neoplasm (MPN) is a rare heterogeneous group of clonal hematological malignancy. We aim to describe the clinico-pathological features, treatment, outcomes and complications of this disorder. Methods: It is an ambispective study. All Ph negative MPN patients registered during 2001 to 31st December 2015 at our institute were reviewed for demographic data, diagnosis based on WHO 2008 criteria, treatment, complications and outcomes. SPSS software was used. Results: There were 55 patients registered with PMF (37), ET (9), PV (7), CNL (1) and MPN-U (1). PMF showed median age 51.2 years (23-70), male: female ratio of 1.46, symptomatic (36), splenomegaly (29), mean hemoglobin 9.7 gm/dl (3-16), JAK2 mutation positive (14), CALR mutation positive (1). Most of the patients were DIPSS intermediate-1 risk 22 (59.4%) grouping. They received hydroxyurea (13), steroids (9), ruxolitinib (6), immunomodulators/steroids (4), aspirin (3), allogeneic stem cell transplantation (2), interferon (1), radiation (1), danazol (1) and observation (1). Median OS was not reached. OS at 5 years is 84% (95% CI 70% to 98%). Survival probability at 36 months is significant for circulating blasts <1% and high bone marrow fibrosis but not significant on multivariate analysis. Progression probability at 36 months is significant for circulating blast <1% and high DIPSS score but not significant in multivariate analysis. PV showed median age 58 years (23-70), male: female ratio 6:1, symptomatic (7), splenomegaly (6), mean hemoglobin 18.4 gm/dl (16.6-21.5), JAK2 mutation positivity (5), low risk (2), high risk (5). They received hydroxyurea (6), phlebotomy (3) and aspirin (1). Five out of 7 patients are in stable condition. ET showed median age 39 years (24-72), male: female ratio 2:1, symptomatic (4), splenomegaly (2), mean hemoglobin 12.2 gm/dl (7.5-15.4), JAK2 mutation positivity (4), low risk (7) and high risk (2). They received aspirin (6), hydroxyurea (5), and observation (1). Three patients are in stable condition. CNL (1) developed pneumothorax and was lost to follow up. MPN-U (1) received hydroxyuea. Seven died due to pneumonia (5), transfusion hypersensitivity (1) and AML transformation (1). Conclusions: PMF is the most common Ph negative MPN in our institute with DIPSS intermediate-1 being the most common risk group. At a median follow up of 36 months overall survival at 5 years is 84%.