Bevacizumab Plus Chemotherapy as First-Line Treatment for Patients with Metastatic Colorectal Cancer: Results from a Spanish Observational Study

Abstract

 Background: This observational study evaluated the efficacy and safety of treatment with bevacizumab plus chemotherapy until disease progression (PD) in Spanish patients with metastatic colorectal cancer (mCRC).

Methods: This multicentre, retrospective, observational analysis included patients receiving bevacizumab plus fluoropyrimidine-based chemotherapy as first-line treatment for mCRC who then developed PD. All patients received treatment in hospital oncology departments and none received bevacizumab as part of a clinical trial. Patients discontinuing treatment with bevacizumab for reasons other than PD were excluded. The primary endpoint was PFS; secondary endpoints were overall response rate (ORR) and safety.

Results: Overall, 165 patients were evaluable for analysis: median age 63.0 years; male/female 62%/38%; ECOG performance status 0/1/2 55%/43%/2%. Median duration of bevacizumab treatment was 8.7 months. ORR was 48.5% (6 complete and 74 partial responses) and disease control rate was 74%. Median progression-free survival (PFS) was 8.4 months (95% CI 7.2-9.6). Patients receiving oxaliplatin- or irinotecan-based regimens had median PFS of 9.2 and 7.7 months, respectively; those receiving treatment not containing either oxaliplatin or irinotecan had a median PFS of 6.1 months. KRAS status did not have a statistically significant effect on PFS (9.5 vs. 7.8 months for KRAS wild-type vs. mutant tumours, respectively; p=0.647) or ORR (44.8% vs. 52.6%, respectively; p=0.391). The most common grade 3/4 adverse events were: diarrhoea (7%), paraesthesia (7%), neutropenia (3%), cutaneous toxicity (2%), and thrombocytopenia (2%).

Conclusions: Treatment with bevacizumab plus standard chemotherapy is an effective and well-tolerated option for patients with mCRC who continue treatment until PD.