Aetiology of sex differences in colorectal cancer

Association of demographic and treatment variables in long-term colon cancer survival

The purpose of this study is to examine demographic and treatment variables because they relate to 5-year survival in colon cancer. The study design is analysis of 174 471 patients with colon and rectosigmoid cancer as reported to the American College of Surgeons National Cancer Data Base. Factors associated with a reduced risk of mortality included female gender (hazard ratio = 0.89; 95% confidence interval, 0.87-0.90), education status (hazard ratio = 0.87; 95% confidence interval, 0.85-0.89), increased number of lymph nodes resected (compared with <8, 8-12: hazard ratio = 0.90; 95% confidence interval, 0.89-0.92; >12: hazard ratio = 0.79; 95% confidence interval, 0.77-0.80), and addition of chemotherapy (hazard ratio = 0.69; 95% CI, 0.68-0.71). African American race (hazard ratio = 1.14; 95% confidence interval, 1.11-1.18) and increasing age correlated with an increased hazard risk (61-75 years: hazard ratio = 1.26; 95% confidence interval, 1.23-1.29; >or=76 years: hazard ratio = 2.15; 95% confidence interval, 2.09-2.21, compared with age <60 years). Survival in colon cancer is significantly impacted by patient's age, race, gender, and education status but not by income or area of residence.

Gender differences in colorectal cancer: implications for age at initiation of screening

There is some variation regarding age at initiation of screening for colorectal cancer (CRC) between countries, but the same age of initiation is generally recommended for women and men within countries, despite important gender differences in the epidemiology of CRC. We have explored whether, and to what extent, these differences would be relevant regarding age at initiation of CRC screening. Using population-based cancer registry data from the US and national mortality statistics from different countries, we looked at cumulative 10-year incidence and mortality of CRC reached among men at ages 50, 55, and 60, and found that women mainly reached equivalent levels when 4 to 8 years older. The gender differences were remarkably constant across populations and over time. These patterns suggest that gender differentiation of age at initiation may be worthwhile to utilise CRC-screening resources more efficiently.