Alpha-interferon does not increase the efficacy of 5-fluorouracil in advanced colorectal cancer

Two meta-analyses were conducted to quantify the benefit of combining α-IFN to 5FU in advanced colorectal cancer in terms of tumour response and survival. Analyses were based on a total of 3254 individual patient data provided by principal investigators of each trial. The meta-analysis of 5FU ± LV vs. 5FU ± LV + α-IFN combined 12 trials and 1766 patients. The meta-analysis failed to show any statistically significant difference between the two treatment groups in terms of tumour response or survival. Overall tumour response rates were 25% for patients receiving no α-IFN vs. 24% for patients receiving α-IFN (relative risk, RR = 1.02), and median survivals were 11.4 months for patients receiving no α-IFN vs. 11.5 months for patients receiving α-IFN (hazard ratio, HR = 0.95). The meta-analysis of 5FU + LV vs. 5FU + α-IFN combined 7 trials, and 1488 patients. This meta-analysis showed an advantage for 5FU + LV over 5FU + α-IFN which was statistically significant in terms of tumour response (23% vs. 18%; RR = 1.26;P = 0.042), and of a borderline significance for overall survival (HR = 1.11;P = 0.066). Metastases confined to the liver and primary rectal tumours were independent favourable prognostic factors for tumour response, whereas good performance status, metastases confined to the liver or confined to the lung, and primary tumour in the rectum were independent favourable prognostic factors for survival. We conclude that α-IFN does not increase the efficacy of 5FU or of 5FU + LV, and that 5FU + α-IFN is significantly inferior to 5FU + LV, for patients with advanced colorectal cancer. © 2001 Cancer Research Campaign http://www.bjcancer.com