Use of Bevacizumab for Elderly Patients With Stage IV Colon Cancer: Analysis of SEER-Medicare Data

Abstract

BackgroundBevacizumab is used for the treatment of metastatic colon cancer in conjunction with first-line chemotherapy. In this study, we examined receipt of first-line bevacizumab and predictors of its use among older patients with stage IV colon cancer. Materials and MethodsWe used data from the Surveillance, Epidemiology, and End Results-Medicare dataset to identify patients with stage IV colon cancer diagnosed from 2005 to 2013 who received FOLFOX (5-fluorouracil/leucovorin/oxaliplatin) or FOLFIRI (5-fluorouracil/leucovorin/irinotecan) as first-line therapy. We used multivariable regression analysis to determine demographic and clinical factors associated with use of concomitant bevacizumab. ResultsWe identified 3785 patients with stage IV colon cancer who met our eligibility criteria. Of these, 2352 (62.1%) received bevacizumab. Bevacizumab use has decreased over time from 68.2% in 2005 to 57.6% in 2013 (odds ratio [OR], 0.94; 95% confidence interval [CI], 0.91-0.97). Patients were less likely to receive bevacizumab if they were older (compared with 65-69 years, ≥ 80 years: OR, 0.64; 95% CI, 0.52-0.80), or had multiple comorbidities (compared with comorbidity score of 0, score of 1: OR, 0.73; 95% CI, 0.60-0.89). ConclusionOver one-half of elderly patients received bevacizumab as part of their first-line therapy for stage IV colon cancer. Bevacizumab use has been slowly decreasing since 2005. Newer anti-epidermal growth factor receptor treatments have not been supplanting bevacizumab, as first-line biologic use in general has also decreased during this time period.