Risk/benefit profile of bevacizumab in metastatic colon cancer: a systematic review and meta-analysis.

BACKGROUND: Bevacizumab, an anti vascular endothelial growth factor antibody is licensed in several tumours and widely used in colorectal cancer. However, bevacizumab has several adverse effects which may appear unexpectedly and differ according to the tumour.

AIMS: The aim of this work is to quantify the overall risk of bevacizumab-related side effects in patients affected by advanced colorectal cancer and to compare them with its overall benefit.

METHODS: We performed a systematic review and meta-analysis investigating bevacizumab in metastatic colorectal cancer. Our primary endpoint was safety and secondary endpoints were overall survival and progression-free survival. The relative risks for side effects were calculated with their 95% confidence interval using the inverse of variance method. For statistically significant relative risks, number needed to harm were calculated.

RESULTS: We retrieved six out of 17 eligible papers encompassing 3385 patients. Only hypertension (relative risk 2.98 95% confidence interval 2.32-3.84), gastrointestinal perforations (relative risk 5.04 95% confidence interval 1.72-14.79) and bleeding (relative risk 2.07 95% confidence interval 1.19-3.62) were significantly increased. Bevacizumab significantly improved both overall survival (HR 0.80 95% confidence interval 0.71-0.91) and progression-free survival (hazard ratio (HR) 0.62 95% confidence interval 0.52-0.74). Number needed to treat for overall survival is 12, whilst number needed to harms ranges from 2 to 14.286.

CONCLUSION: These results show that the benefits of the treatment with bevacizumab outweigh the toxicity that may occur: enough to justify its use in advanced colorectal cancer.