Real-world outcomes of treatment for acute lymphoblastic leukemia during adolescence in a financially restricted environment: Results at a single center in Latin America

Abstract

Objective: There is a paucity of the studies of adolescents with acute lymphoblastic leukemia (ALL). This is more noticeable in low- and middle-income countries. The international 5-year event-free survival (EFS) and overall survival (OS) for this age group is around 80%, with pediatric-inspired protocols offering better results.

Methods: A retrospective analysis of adolescents aged 16-20 diagnosed with ALL during the period 2004-2015 treated with a high-risk pediatric protocol at an academic center from a middle-income country was performed. Five-year OS and EFS were estimated by the Kaplan-Meier analysis. Hazard ratios of relapse and death were estimated by the Cox regression model.

Results: Five-year EFS and OS for 57 adolescents were 23.3% and 48.9%, respectively. From the 41 patients who achieved complete remission, 24 (58.5%) relapsed. Bone marrow and central nervous system were the most frequent sites of relapse. Hazard ratio of treatment failure and death for patients with organomegaly at diagnosis was 2.026 and 2.970, respectively. Treatment-related toxicity developed in 31 (54.4%) patients and febrile neutropenia was the most frequent in 14 (24.6%) cases. Twelve patients (21.1%) had poor adherence to treatment.

Conclusions: High relapse rate and low 5-year EFS compared with international standards, was documented. Use of intensified pediatric regimens, adherence to proven effective medications, improved supportive care, and prevention of abandonment are necessary to improve survival rates in these patients.

Keywords: acute lymphoblastic leukemia; adherence; adolescence; compliance; survival rates.