Trends in all-cause mortality among patients with chronic myeloid leukemia: a Surveillance, Epidemiology, and End Results database analysis

Abstract

Background: Outcomes for patients with chronic myeloid leukemia (CML) have improved after the advent of tyrosine kinase inhibitors (TKIs), which target the BCR/ABL fusion gene product. Nonetheless, differences in survival persist between age groups. The authors performed a retrospective cohort study using the Surveillance, Epidemiology, and End Results (SEER) database to assess 5-year overall survival (OS) in various patient age groups.

Methods: Patients who had a diagnosis of CML were identified using the SEER 19 registries database. Patients who were included had SEER diagnosis codes for CML not otherwise specified (code 9863) and BCR/ABL-positive CML (code 9875) diagnosed between January 2000 and December 2005. Patients were divided into cohorts based on age at diagnosis: ages 15 to 44 years, 45 to 64 years, 65 to 74 years, and 75 to 84 years. OS was estimated using the Kaplan-Meier method, and Cox regression was used to estimate predictors of patient survival.

Results: In total, 5138 patients with a new CML diagnosis were identified. Five-year OS improved for all patients between the years 2000 and 2005. Compared with patients who were diagnosed in 2000, 5-year survival improved among patients ages 15 to 44 years (hazard ratio [HR] for mortality, 0.424; P < .0001), ages 45 to 64 years (HR, 0.716; P = .0315), and ages 65 to 74 years (HR, 0.692; P = .0126); and patients ages 75 to 84 years had an increased 5-year OS rate from 19.2% in 2000 to 36.4% in 2005 (HR, 0.568; P < .0001).

Conclusions: OS at 5 years improved among all patients, including those ages 75 to 84 years, a group with historically poor outcomes. However, older age retained an association with worse survival, suggesting opportunities for further progress.

Keywords: age groups; bcr-abl; chronic myeloid leukemia; population survival; tyrosine kinase inhibitor.