Observational Cohort Study of Patients With Metastatic Colorectal Cancer Initiating Chemotherapy in Combination With Bevacizumab (CONCERT)

The CONCERT cohort study (observational cohort study of patients with metastatic colorectal cancer initiating chemotherapy in combination with bevacizumab) was conducted to address French specificities on the use of bevacizumab in patients with metastatic colorectal cancer (mCRC) in everyday practice. CONCERT was a multicenter, prospective, observational study that included patients with mCRC, initiating bevacizumab combined with chemotherapy and followed up for ≤ 36 months. The median progression-free and overall survival duration observed in the real-life setting were in line with results of randomized clinical trials of bevacizumab plus chemotherapy for first- and second-line therapy for patients with mCRC. Background The CONCERT study (observational cohort study of patients with metastatic colorectal cancer initiating chemotherapy in combination with bevacizumab) aimed to describe patient characteristics, bevacizumab use, its efficacy in terms of progression-free survival (PFS) and overall survival (OS), and its safety in patients with metastatic colorectal cancer (mCRC) treated in daily medical practice. Patients and Methods CONCERT was an observational, prospective, multicenter, cohort study conducted in France. Patients with mCRC initiating bevacizumab combined with chemotherapy were included and followed up for ≤ 36 months. Results Overall, 737 evaluable patients were assessed, and 71%, 21%, and 8% initiated bevacizumab as first-, second-, or third-line therapy or more, respectively. Their mean age was 64.5 years (range, 25-88 years), and 60% were men. Bevacizumab was mainly started at 5 mg/kg every 2 weeks (95%) and mostly combined with FOLFIRI (leucovorin, 5-fluorouracil, irinotecan; 68.0%) or FOLFOX (leucovorin, 5-fluorouracil, oxaliplatin; 22.0%). The median PFS was 10.4 months (95% confidence interval [CI], 9.6-11.3) in first-line, 8.5 months (95% CI, 7.0-9.2) in second-line, and 6.3 months (95% CI, 4.5-8.9) in third-line or beyond. The corresponding median OS was 25.3 months (95% CI, 21.5-28.6), 19.1 months (95% CI, 15.7-22.6), and 14.9 months (95% CI, 11.6-20.4). In first-line treatment, primary tumor resection and oxaliplatin-based chemotherapy were prognostic of a longer PFS. Eastern Cooperative Oncology Group performance status ≥ 2, > 1 metastatic sites, and intermediate or high risk using the Köhne prognostic index were associated with shorter PFS. The safety profile of bevacizumab combined with chemotherapy was comparable to that found by other observational studies of mCRC. Conclusion The efficacy and safety results of bevacizumab plus chemotherapy as first- and second-line treatment of mCRC in daily practice in the CONCERT observational, prospective study were in line with those from randomized clinical studies.