Outcomes of Patients with NPM1 Positive Acute Myeloid Leukemia, An Experience from a Tertiary Care Hospital in Karachi, Pakistan

Abstract

Objectives: To determine the response to induction chemotherapy, overall survival, and relapse rate in patients with NPM1-positive acute myeloid leukaemia.

Methodology Patients diagnosed with AML from January 2015 to July 2022 at Aga Khan University Hospital Karachi were included in the study. Patient demographics, clinico-haematological parameters, and molecular analysis for the NPM1 mutation were performed. Response to standard induction chemotherapy, overall survival, and relapse rate were assessed.

Results: A total of 76 cases of AML were analysed. The mean age of the sample was 33.7 years, of which 63.2% were males and 36.8% were females. The patients were stratified into two groups: those who were positive for NPM1 while negative for FLT3 (NPM+/FLT3-), representing 18.4%, and those who were negative for both NPM1 and FLT3 (FLT3-/NPM-), representing 81.6% of cases. On day 28 post-induction, the complete remission rate was 78.6% in the NPM1 positive group and 77.4% in the NPM1 negative group. In the NPM1+/FLT3-group, 54.5% of cases who were in remission at day 28 subsequently relapsed, compared to 50.0% of NPM1-/FLT3-cases. The overall survival could not be assessed between both the groups due to the low number of deaths.

Conclusion: AML patients harbouring only the NPM1 mutation do not show significant differences in outcome as compared to those negative for both mutations.