Utility of end of induction bone marrow biopsy and survival outcomes in acute promyelocytic leukemia treated with fixed-dose induction regimen

Significant variations exist related to the end of induction practices in the management of Acute Promyelocytic Leukemia (APL). These variations include all-trans retinoic acid (ATRA)-arsenic trioxide (ATO) in fixed doses versus continuation until hematologic complete remission (CR) and performance versus omission of post-induction bone marrow biopsy to confirm morphological CR. A retrospective chart review was conducted of 61 patients (42 low/intermediate-risk and 19 high-risk) aged & GE; 18 years with newly diagnosed APL treated with fixed duration ATRA-ATO +/- cytoreduction at a tertiary medical center from December 2012 through March 2020. Of the 54 patients with post-induction bone marrow biopsy results, 52 (96%) demonstrated no morphologic evidence of APL while the remaining were equivocal. After 2.6 years median follow-up, no relapses occurred. The estimated 2-year overall survival rate of 95% suggests excellent outcomes with a fixed ATO induction regimen and safe omission of post-induction bone marrow biopsy irrespective of hematologic parameters.