The Unmet Need in Chronic Lymphocytic Leukemia: Impact of Comorbidity Burden on Treatment Patterns and Outcomes in Elderly Patients

Abstract

Introduction: Chronic lymphocytic leukemia (CLL) is a disease of the elderly. Elderly patients often have increased comorbidity burden and loss of organ reserve that may impact their ability to tolerate cancer therapy. We described realworld characteristics of typical CLL patients and identified factors predictive of receiving treatment. Methods: A retrospective cohort analysis of 8343 first primary CLL patients was performed using the linked Surveillance, Epidemiology, and End Results-Medicare database. Patients were diagnosed from 1/1/1998 to 12/31/2007, >66 years, and continuously enrolled in Medicare Parts A and B in the year prior to diagnosis. Comorbidity was examined using the National Cancer Institute comorbidity index and the Cumulative Illness Rating Scale. Cox and Logistic regression modeling assessed patient characteristics predictive of receiving treatment within the first year after diagnosis. Results: Median follow-up time from diagnosis was 782 days. During the study time period, there were 3366 (40%) treated patients and 4977 (60%) untreated. Even among those diagnosed with advanced stage (n = 4213), 57% were not treated. Treated patients were younger at diagnosis compared to untreated (76 vs. 79; p < 0.0001). In general, as age increased, the incidence and severity of comorbidities increased. In multivariate regression analyses, the treatment rate was significantly lower among patients >80 years, females, and with early stage disease; and significantly decreased with increasing comorbidity burden. Conclusions: Age, gender, comorbidity and stage were predictive of receiving treatment. Among patients with advanced stage, 57% were not being treated possibly due to older age and/or higher comorbidity burden.