Role for gender in colorectal cancer risk: a Taiwan population-based study

Gender differences in the prognosis of colorectal cancer (CRC) remain controversial. The aim of this study was to complete a comprehensive analysis of gender differences in CRC survival derived from population registries in Taiwan. We analyzed survival data for patients diagnosed with CRC between 1998 and 2005 derived from the Taiwan Cancer Registry database. During this time period, 65,113 patients were registered, and 62,060 patients were eligible. Gender differences in overall survival and cancer-specific survival were analyzed by use of the Kaplan-Meier method. We then modeled the risk in different genders by use of a multivariate proportional hazard (Cox) model adjusting for possible confounders of survival. The 5-year period overall and cancer-specific survivals were significantly higher in women than in men [51.84 % (95 % confidence interval (CI), 51.22-52.46) vs. 47.68 % (95 % CI, 47.14-48.22), log-rank p < 0.001; and 56.44 % (95 % CI, 55.82-57.07) vs. 53.47 % (95 % CI, 52.92-54.01), log-rank p < 0.001, respectively]. Subgroup analysis revealed higher overall and cancer-specific survivals in women between 50 and 80 years age and those with adenocarcinomas (p < 0.001). By use of Cox modeling, we noted a decreased hazard ratio (HR) for death from CRC in women compared with men (HR, 0.820-0.971), especially in the 50-80-year age group. All estimated HRs, after adjusting for age, tumor histology, and tumor site, had significant trends of a decreasing risk of death from CRC in women. Our findings suggest that overall and cancer-specific survival advantage was most evident in women between 50 and 80 years of age.