Overall and age-specific risk advancement periods of colorectal cancer for men vs women: Implications for gender-sensitive screening offers?

Colorectal cancer (CRC) incidence and mortality are higher among men than among women. We aimed to estimate overall and age-specific risk advancement periods (RAPs) for men compared to women, which quantify how many years earlier comparable levels of risk are reached by men. RAPs were derived by Cox regression models among 331 224 participants aged 40 to 69 at baseline of the UK Biobank with no previous diagnosis of CRC and no previous CRC screening examination who were followed with respect to CRC incidence for up to 13 years. Men were at substantially higher risk of CRC than women in age groups 50 to 59 and 60 to 69, with RAPs (95% confidence intervals) as high as 8.7 (4.5-13.0) and 6.2 (4.5-7.9), respectively. These RAPs were higher than those for family history of CRC in these age groups. By contrast, no significant sex difference but a major impact of family history was seen in age group 40 to 49 (P-value for interaction between sex and age = .00079). The observed patterns suggest that consideration of gender-specific starting ages of screening might be warranted in countries in which screening offers start at ages above 50 years.