Prognostic value of complete remission with superior platelet counts in acute myeloid leukemia.

Background: Complete remission (CR) in acute myeloid leukemia (AML) is defined as having ≤5% leukemic blast cells in the bone marrow and return of normal hematopoiesis after the first induction cycle. There is a subset of patients, however, who achieve reduction of leukemic blast cells with a subnormal platelet count, designated as CR with incomplete platelet recovery (platelet count, ≤100,000/mcL; normal, 150,000-450,000/mcL), which is associated with inferior outcomes when compared with CR. Furthermore, there is another subset of patients with CR but superior platelet counts (≥400,000/mcL) whose prognostic significance is unclear.
Objective: To establish whether CR with superior platelet counts is associated with better outcomes and can be used as a separate entity for prognostication.
Methods: A retrospective chart review of 104 cases of AML was conducted. The highest platelet count during days 25-35 from initiation of induction chemotherapy (designated as day 30 platelet count) was documented. A multivariate analysis for other factors such as age, sex, risk categories, day 14+ plasma cell count (average plasma cell percentage at days 14-21), infections, allogeneic bone marrow transplant, and remission status was done.
Results: Day 30 platelet count was found to be an independent predictor of survival in AML. On the multivariate analysis, the subgroup with superior platelet counts (≥400,000/mcL) was found to be associated with better outcomes.
Limitations: Results need to be validated in a larger cohort.
Conclusions: CR with superior platelet recovery (≥400,000/mcL) is a unique subcategory in itself and has prognostic significance. This may help better assess response to chemotherapeutic agents and aid in further decision-making regarding treatment.
(©2016 Frontline Medical Communications.)