7016 Background: Therapy selection in chronic lymphocytic leukemia (CLL) patients is based on disease severity as well as patient characteristics such as age and comorbidity. While treatment outcomes are mostly available from clinical trial data in younger patients, less is known about the effect of comorbidities on outcomes in elderly CLL patients in the real-world setting. Methods: The linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database was utilized in this retrospective cohort analysis of 3,366 first primary CLL patients. Patients were diagnosed between 1/1/1998-12/31/2007, were >66 years, continuously enrolled in Medicare Part A and B with no HMO coverage in the year prior to diagnosis and received first-line treatment with any oral or infused therapy. CLB is covered by Medicare Part D and data for its use were only available from 2007-2009 in the dataset. Cox regression with backward elimination and propensity score weighted Cox regression estimated the relative risk of death. Date of last follow-up was 12/31/2009. Results: There were 153 CLB, 606 R-mono, 702 R+IV Chemo, and 1,905 IV Chemo-only patients. CLB and R-mono patients were older at diagnosis with mean age of 77 compared to R+IV Chemo (73 years) and IV Chemo-only (76 years; p<.0001). Patients administered R-mono had a higher comorbidity burden and more advanced disease compared with other treatment groups. In the survival analysis we compared CLB to R-mono during the time period 2007-2009 and R+IV Chemo to IV Chemo-only during the time period 1998-2009. The adjusted multivariate survival analysis revealed a significant mortality risk reduction with R+IV Chemo compared with IV Chemo-only patients (HR, 0.72; 95% CI, 0.62-0.84) while a non-significant mortality risk reduction was noted with R-mono compared to CLB patients (HR, 0.47; 95% CI, 0.21-1.05). Older age and increasing comorbidity score were significantly associated with higher mortality. Conclusions: These findings suggest that chemo-immunotherapy is more effective than chemotherapy in an elderly population with a high prevalence of comorbidity. This extends the conclusions from clinical trials in younger, medically fit patients.
Mortality risk reduction differs according to bisphosphonate class: a 15-year observational study
