Cetuximab versus bevacizumab following prior FOLFOXIRI and bevacizumab in postmenopausal women with advanced KRAS and BRAF wild-type colorectal cancer: a retrospective study

BACKGROUND: An upgraded understanding of factors (sex/estrogen) associated with survival benefit in advanced colorectal carcinoma (CRC) could improve personalised management and provide innovative insights into anti-tumour mechanisms. The aim of this study was to assess the efficacy and safety of cetuximab (CET) versus bevacizumab (BEV) following prior 12 cycles of fluorouracil, leucovorin, oxaliplatin, and irinotecan (FOLFOXIRI) plus BEV in postmenopausal women with advanced KRAS and BRAF wild-type (wt) CRC. METHODS: Prospectively maintained databases were reviewed from 2013 to 2017 to assess postmenopausal women with advanced KRAS and BRAF wt CRC who received up to 12 cycles of FOLFOXIRI plus BEV inductive treatment, followed by CET or BEV maintenance treatment. The primary endpoints were overall survival (OS), progression-free survival (PFS), response rate. The secondary endpoint was the rate of adverse events (AEs). RESULTS: At a median follow-up of 27.0 months (IQR 25.1–29.2), significant difference was detected in median OS (17.7 months [95% confidence interval [CI], 16.2–18.6] for CET vs. 11.7 months [95% CI, 10.4–12.8] for BEV; hazard ratio [HR], 0.63; 95% CI, 0.44–0.89; p=0.007); Median PFS was 10.7 months (95% CI, 9.8–11.3) for CET vs. 8.4 months (95% CI, 7.2–9.6) for BEV (HR, 0.67; 95% CI 0.47–0.94; p=0.02). Dose reduction due to intolerable AEs occurred in 29 cases (24 [24.0%] for CET vs. 5 [4.8%] for BEV; p< 0.001). CONCLUSIONS: CET tends to be superior survival benefit when compared with BEV, with tolerated AEs.