Impact of Additional Cytogenetic Abnormalities on the Clinical Behavior of Patients With Chronic Myeloid Leukemia: Report on a Latin American Population.

ABSTRACT

INTRODUCTION: Additional cytogenetic abnormalities (ACA) in patients with chronic myeloid leukemia (CML) are related to an increased risk of treatment failure, leukemic progression, and decreased survival. Currently, there are scarce data available for the Latin American population. The aim of this study was to outline the impact of ACA emergence in Mexican patients with CML. METHODS: We retrospectively analyzed clinical data from adult patients with CML treated with upfront imatinib between January 2001 and December 2016. Two groups were defined for comparison according to the presence or absence of ACA. RESULTS: Ninety-seven patients were included. ACAs were found in 30 patients, 20% at diagnosis and 80% during follow-up. In 90% of the patients, ACA emergence was detected in the CML-chronic phase. Regarding clinical outcomes, the complete cytogenetic response rate (16.5% vs. 59.8%; P < .001), progression-free survival (PFS) at 10 years (76% vs. 95%; P = .009), and failure-free survival (FFS) at 10 years (16% vs. 73%; P < .001) were significantly inferior in the ACA group. Multivariate analysis confirmed that ACA emergence was a deleterious independent prognostic factor for PFS (hazard ratio [HR] 8.9; 95% confidence interval [CI] 1.35-58.4; P = .023) and FFS (HR 3.7; 95% CI 1.54-8.58; P = .003). CONCLUSIONS: This study confirms previously reported data regarding the adverse impact of ACA over clinical outcomes in a Latin American population.