Clinical Profile and Treatment Outcomes in Paediatric and Adult Acute Promyelocytic Leukemia: Experience from a Tertiary Care Centre in Northern India

Introduction: Acute promyelocytic leukemia (APL) is a distinct and highly curable subtype of acute myeloid leukemia. However, early mortality due to hemorrhage, differentiation syndrome (DS), and infections remains a significant challenge, particularly in resource-limited settings. There is a paucity of real-world data from India, where delayed diagnosis and high infection rates may impact outcomes. Methods: This retrospective cohort study included APL patients diagnosed at SGPGIMS, Lucknow, between July 2014 and June 2024. Diagnosis was confirmed via morphology, flow cytometry, and RT-PCR. Patients received risk-adapted induction therapy with ATRA and ATO ± anthracycline. Kaplan-Meier and multivariate Cox regression analyses were performed. Results: Of 102 patients (median age 33 years; 17.6% pediatric), 47% were high-risk. Fever and mucocutaneous bleeding were common presentations; 18.6% had life-threatening hemorrhages, mainly intracranial. Median diagnosis delay was 18 days. DS occurred in 56% of adults and 33% of pediatric patients. Pseudotumor cerebri and hepatotoxicity occurred in 7.8% and 37.6%, respectively. CR was achieved in 76.4% (87% low-risk vs. 64.6% high-risk). Induction mortality (24.5%) was mainly due to bleeding and infections. At a median follow-up of 28 months, 2-year OS was 75.9% (low-risk: 90.4%; high-risk: 65.9%), and DFS was 94.9%. High-risk status, age >50 with comorbidities, low hemoglobin, and poor performance status independently predicted mortality. Conclusions: Early mortality in APL remains high due to delayed diagnosis and bleeding complications. Region-specific challenges necessitate timely intervention and tailored supportive care to improve outcomes in Indian APL patients, especially in pediatric and high-risk groups.