Male gender adversely affects survival following surgery for colorectal cancer

Background: Previous studies have suggested that survival following surgery for colorectal cancer is better in women than men. However, the findings were inconsistent and few studies adjusted for case-mix. The aim of the present study was to establish whether there were gender differences in survival following surgery for colorectal cancer after adjusting for case-mix. Methods: Some 3200 patients who underwent resection for colorectal cancer between 1991 and 1994 in 11 hospitals in Scotland were included in the study. Five-year survival rates, and the corresponding hazard ratios, adjusted for age, mode of presentation, site of tumour, the nature of surgery and Dukes' stage, were calculated for men and women. Results: Overall survival at 5 years was higher in women than men, in those with colonic tumours, those who underwent elective surgery and those who underwent apparently curative resection (all P < 0.001). Cancer-specific survival at 5 years was also higher in women (P = 0.008) and those who underwent elective surgery (P < 0.001). The adjusted hazard ratios, for women relative to men following curative resection, were 0.76 (95 per cent confidence interval (c.i.) 0.68 to 0.85) (P < 0.001) for overall survival and 0.84 (95 per cent c.i. 0.73 to 0.98) (P = 0.021) for cancer-specific survival. Conclusion: Following apparently curative resection for colorectal cancer and after adjusting for case-mix, there was an excess of both cancer-related and intercurrent deaths in men.