A retrospective observational study on the safety and efficacy of first-line treatment with bevacizumab combined with FOLFIRI in metastatic colorectal cancer
BACKGROUND The primary objective of the analysis was to compare duration of survival in patients who received bevacizumab plus 5FU/LV, irinotecan or oxaliplatin based chemotherapy with the survival rate in a combined control groups of patients who received the same protocols alone, without bevacizumab. METHODS Pooling of the data from the several studies allows evaluation of efficacy end points with greater statistical power to detect real differences between the groups of patients who were and were not treated with bevacizumab. The 10 studies have to be used for analysis were well designed, prospective trials conducted in patients with metastatic colorectal adenocarcinoma. RESULTS The median duration of survival was 18/12/11 months median duration of progression free survival was 8.8/7/6.7 months and response rate was 34/14/12% in the 5-FU/LV/bevacizumab group, 5-FU/LV CI group, and bolus 5-FU/LV group, respectively. Difference in OS for patients who received bevacizumab with 5-FU/LV in comparison to 5-FU/LV alone is up to 7 months. The median duration of survival for bevacizumab plus irinotecan-based chemotherapy was 20 months, median duration of progression free survival was 11 months and response rate was 45%. Difference in OS, PFS and RR for patients who received bevacizumab plus irinotecan-based chemotherapy in comparison to irinotecan-based chemotherapy alone is up to 5 months, 4.5 months and 10%. For oxaliplatin-based protocols tumor response was 43-53%, overall survival was 16.4-19.4 months and the median progression free survival was 8-9 months. The median duration of survival was 26 months (benefit is up to 10 months), median duration of progression free survival was 19 months (benefit is up to 10 months) and response rate was 59% (benefit is up to 16%) were achieved for bevacizumab plus FOLFOX4 (oxaliplatin/inf.5FU/LV). CONCLUSIONS Addition of bevacizumab to 5-FU/LV, irinotecan or oxaliplatin-based chemotherapy provided significantly and clinically meaningful improvement in overall survival, disease-free survival and response rate compared with 5-FU/LV, irinotecan or oxaliplatin-based chemotherapy alone in patients with metastatic CRC.