Cetuximab after bevacizumab in metastatic colorectal cancer: Is it the best sequence?

Background: Chemotherapy combinations and addition of cetuximab or bevacizumab to chemotherapy have been shown to improve overall survival of metastatic colorectal cancer (CRC) patients. However, the efficacy of cetuximab when administered after bevacizumab failure is still unknown. Methods: Fifty-eight consecutive patients diagnosed with advanced colorectal cancer between treated with cetuximab following irinotecan failure were included in our analysis. A multivariate Cox model analysis was performed to estimate the effect of previous bevacizumab regimen on survival. Results: Thirteen (22.4%) were pre-treated with anti-VEGF agents. None of them responded to cetuximab, and this subgroup presented a significantly decreased disease-specific survival as compared to treatment-naive patients (9.1 months vs. 4.9 months; p = 0.026). This difference remained statistically significant in a multivariate Cox model after adjusting for age, sex, performance status (PS), and K-RAS status (RR = 2.2; 95% CI: 1.1-4.5, p = 0.03). Conclusion: These study results suggest that a previous anti-VEGF therapy decrease cetuximab efficiency. (C) 2011 Editrice Gastroenterologica Italians S.r.l. Published by Elsevier Ltd. All rights reserved.