AML-317 Long-Term Follow-Up of Acute Promyelocytic Leukemia: Experience From Clinical Hematology Department of Casablanca

Abstract

Acute promyelocytic leukemia (APL) accounts for about 5-10% of all AML cases, its incidence is about 0.1/100,000. The present study was designed to analyze the clinicopathologic features and outcomes in APL. This is a retrospective descriptive study based on medical records and follow-up of APL patients from 2003 to 2021. It includes all patients diagnosed with APL at the Casablanca Hematology Department. The diagnosis was genetically confirmed by detecting the PML-RAR fusion gene or demonstrating the t(15;17). A total of 94 patients with APL were seen between November 2003 and July 2021 in our department. Median age at presentation was 34 years (range, 1-69 years). The gender ratio was 0.7 (40 men and 54 women). Patients from the northwest region of Morocco, which is dominated by Casablanca, accounted for 47 percent of all patients, followed by 15% from the north and 11% from the east. The median duration of symptoms before presentation was 32 days (range, 2-240 days). At the time of presentation, 51 (60%) of the patients had disseminated intravascular coagulation (DIC). The performance status was 1 in 72% of the cases. The hemorrhagic grade was 36% of stage 2. High-risk, intermediate-risk, and low-risk were seen in 32%, 55%, and 13% of patients, respectively. PML-RAR data was available for 34 patients (36%) and karyotyping data for 85 patients (91%). Except for 15 patients (16%) who died at diagnosis, all 79 patients who were followed up on received chemotherapy: 63 patients (78.8%) received APL protocol and 18 patients (19.8%) Pethema. At the end of induction chemotherapy, 68 patients (86%) achieved complete hematologic remission, while 11 patients (14%) died. 3 patients relapsed after maintenance treatment including 2 cases of neurological relapse and one case of bone marrow relapse, all died. At 4 years, the event-free survival and overall survival rates were 62% and 62%, respectively. Early death remains the major reason for treatment failure. Retrospective studies have reported an early death rate of 7.2-21.1%. In our population, it represents 16%. APL has progressed from a fatal disease to one that is highly curable in the last decade.