Background
Several chemotherapy regimens using bevacizumab have been developed. Our goal was to investigate regimens that have demonstrated significant clinical activity in patients with metastatic colorectal cancer (mCRC).
Materials and Methods
Six hundred and sixty six patients with mCRC who received first-line chemotherapy combination with bevacizumab were studied. Fluoropyrimidine (F) plus irinotecan (I)-based (FI-bev), F plus oxaliplatin (O)-based (FO-bev), and F-based (F-bev) treatment regimens were compared with respect to progression-free survival (PFS) and overall survival (OS).
Results
The median PFS of FI-bev (n = 414) was 10.9 months (95 % CI 10–11.8), of FO-bev (n = 211) was 9.4 months (95 % CI 8.3–10.4), and of F-bev (n = 41) was 9.5 months (95 % CI 5.9–13.1) (p = 0.089). The median OS of FI-bev was 26.3 months (95 % CI 21.7–30.9), of FO-bev was 27 months (95 % CI 24.3–29.7), and of F-bev was 23.3 months (95 % CI 12.7–33.9) (p = 0.102). In KRAS wild-type patients, the median PFS of FI-bev group was significantly longer than FO-bev group (10.5 vs. 9.1 months, p = 0.006). The FI-bev group had better OS than FO-bev group with borderline significance (p = 0.058). The FI-bev group had significantly longer OS than F-bev group. Patients who underwent metastasectomy or those with Eastern Cooperative Oncology Group performance status (ECOG-PS) ≤1 had longer PFS and OS independent of the type of chemotherapy regimen.
Conclusion
FI-bev may be the preferred frontline regimen for patients with KRAS wild-type mCRC. Metastasectomy and performance score were the strongest positive predictors of OS and PFS regardless of backbone chemotherapy regimen.