Burden of Cancer Mortality in the Canadian Armed Forces, 1976-2012: A Retrospective Cohort Study.

Background: Military personnel may have potential exposures to carcinogens during their military careers. However, the generalizability of causal evidence between occupational exposures and cancer outcomes in military personnel is limited. This study aims to describe the epidemiology cause-specific cancer mortality in still serving and released Canadian Armed Forces (CAF) personnel recruited between 1976 and 2012.

Methods: Data came from the Canadian Forces Cancer and Mortality Study II (CF CAMS II), a record-linkage study of approximately 228,685 CAF Regular Force personnel and Reservists. Sex-stratified standardized mortality ratios (SMR) were calculated for each neoplasm subcategory, with the Canadian general population (CGP) as the reference.

Results: Approximately 1,450 deaths were attributable to neoplasms. Cancer mortality was lower in both men and women with military service (SMR = 0.77 and 0.78, respectively) versus CGP. Females had a significantly lower risk of breast cancer. Males in the cohort had a significantly lower risk of lip, oral cavity and pharynx, digestive organs, respiratory and intrathoracic organs, bone and articular cartilage, and mesothelial and soft-tissue cancers. However, males also had a significantly increased risk for neoplasms of the central nervous system and lymphoid cells, as well as for certain specific cancer diagnoses.

Conclusions: Current and former CAF personnel were at comparable, or lower risk than, the CGP for cancer-related deaths. However, there was an increased risk for certain neoplasm subcategories and specific cancers.

Impact: These findings contribute to the limited body of evidence investigating the link between military service and cancer mortality.