Survival benefit of chemotherapy in metastatic colorectal cancer: a meta-analysis of randomized controlled trials

To estimate the magnitude of benefit of chemotherapy in prolonging survival for patients with metastatic colorectal cancer, a metaanalysis of randomiz ed controlled trial was performed. A systematic search was performed to ide ntify randomized trials comparing chemotherapy with observation or supporti ve care alone. Trials were assessed for quality of reporting, publication b ias and heterogeneity. Relative risks for outcomes from published data were pooled using a random-effects model. Seven trials with 614 patients were i ncluded. All trials used fluoropyrimidine-based chemotherapy, through a var iety of routes and schedules, including intravenous, intra-portal and hepat ic arterial infusion. Compared with the 'no-chemotherapy' arm, chemotherapy significantly reduced 1-year mortality (risk ratio 0.69; 95% confidence in terval (CI) 0.60-0.81, P < 0.00001). The mortality at 2 years was not signi ficantly different (risk ratio 0.93; 95% CI 0.87-1.00, P = 0.053). Between- trial comparisons demonstrated benefit with a variety of routes and schedul es. Chemotherapy significantly prolongs 1-year survival for patients with m etastatic colorectal cancer, and should be offered to those with good perfo rmance status. (C) 2000 Cancer Research Campaign.