Survival Outcomes of Bevacizumab Beyond Progression in Metastatic Colorectal Cancer Patients Treated in US Community Oncology

This retrospective analysis evaluated survival outcomes in patients with metastatic colorectal cancer (mCRC) receiving second-line treatment containing bevacizumab beyond progression (BBP) or No-BBP after progression on a first-line bevacizumab-based regimen in a community oncology setting. Multivariate analyses showed that BBP was associated with prolonged overall survival (OS) (hazard ratio [FIR], 0.76; 95% confidence interval [Cl], 0.61-0.95) and postprogression OS (HR, 0.74; 95% Cl, 0.60-0.93) after adjusting for potential confounders. Background: Bevacizumab prolongs OS when added to first- or second-line chemotherapy for mCRC. This retrospective analysis evaluated the association between the continued use of BBP and survival outcomes in mCRC patients treated in a community oncology setting. Patients and Methods: Data were derived from the US Oncology iKnowMed electronic medical record system. Patients with mCRC who received first-line bevacizumab-containing therapy between July 1, 2006 and June 30, 2009, were dichotomized into 2 second-line treatment cohorts: those receiving BBP and No-BBP. Clinical outcomes, including OS and postprogression OS (ppOS; time from start of second-line therapy to any-cause death), were calculated using Kaplan-Meier methods. A Cox proportional hazards model was used to assess the effects of patient and treatment characteristics on survival outcomes, adjusting for covariates. Results: Overall, 573 patients met the inclusion criteria for analysis-BBP (n = 267) and No-BBP (n = 306). Median OS and ppOS were longer in the BBP cohort (27.9 and 14.6 months, respectively) compared with the No-BBP cohort (21.4 and 10.1 months). According to multivariate analyses, BBP was associated with longer OS (HR, 0.76; 95% Cl, 0.61-0.95) and ppOS (HR, 0.74; 95% Cl, 0.60-0.93) after adjusting for potential confounders. Conclusions: In the community oncology setting, BBP treatment was correlated with prolonged OS and ppOS in patients with mCRC. These results provide insight into real-world patterns of care and resultant bevacizumab use in this patient population.