Incidence of Colorectal Cancer Among Active Component Service Members, 2010-2022

Colorectal cancer, which is more predominant among men than women, has been shown to be associated with environmental and occupational risk factors experienced by military members. The Defense Medical Surveillance System (DMSS) was used to determine the crude and age-adjusted incidence rates of colorectal cancer among active component service members from all military services from January 1, 2010 to December 31, 2022. Results from this analysis show higher crude incidence rates of colorectal cancer among those who are older and male. The overall age-adjusted incidence rate throughout the surveillance period ranged from 3.56 (95% CI: 2.54-4.58) to 7.92 (95% CI: 5.98-9.86) cases per 100,000 person-years. Age-adjusted colorectal cancer rates were similar for males and females (4.46 and 4.33 cases per 100,000 person-years, respectively) and rates were relatively similar by service as well as race and ethnicity. This finding could be attributed to the small number of cases in this study due to better screening practices in the Military Health System (MHS). Although non-Hispanic Black service members have historically had the highest incidence of colorectal cancer within the U.S. military, this study observed similar rates of colorectal cancer for all races and ethnicities after adjusting for age. Incident rates of colorectal cancer within the U.S. military increase monotonically with age, with service members over the age of 45 with the highest incidence, re-enforcing the need to promote wellness screening among military populations. The importance of the DHA guideline changes that decreased colorectal screenings to age 45 years is significant.