Survival of patients with KRAS wild-type metastatic colorectal cancer is identical after sequential treatment with cetuximab and bevacizumab regardless of the sequence - A retrospective single-center study

Objective: To investigate the overall survival of patients with KRAS wild-type metastatic colorectal cancer (mCRC) after sequentially receiving both bevacizumab and cetuximab during the course of treatment.

Methods: Twenty-six mCRC patients who received both bevacizumab and cetuximab at the Sun Yat-sen University Gastrointestinal Hospital were retrospectively analyzed. Group A (n = 8) comprised patients who received bevacizumab first, and group B (n = 18) comprised those who received cetuximab first. The objective response rate, progression-free survival, and overall survival were compared.

Results: Baseline characteristics between the two groups were statistically similar. The objective response in groups A and B patients was 62.5% and 66.6%, respectively (P = 0.132). The median progression-free survival for groups A and B patients was 13 and 10 months, respectively (P = 0.798). The median overall survival for the entire cohort was 42 months, 44 months for group A and 39 months for group p B (P = 0.862) patients, respectively. Patients aged <40 years had worse survival than those aged ≥40 years (22 vs 44 months; P = 0.029). Patients with synchronous metastasis had worse survival than those with metachronous metastasis (unreached and 36 months, respectively). In multivariate analyses, synchronous metastasis and age remained statistically significant. The hazard ratio for synchronous metastasis was 4.548, and the HR for patients aged ≥40 years was 0.237.

Conclusion: A longer median survival time was observed in patients regardless of the targeted therapy sequence, which warrants further investigation.