Cancer incidence in male and female Canadian Armed Forces personnel and Veterans enrolled between 1976 and 2016: a retrospective population-based cohort study.

Objectives: To describe rates of overall and type-specific primary cancers in Canadian Armed Forces (CAF) personnel and Veterans with a first enrolment in the CAF between 1976 and 2016, with comparisons to the Canadian general population (CGP).

Methods: This retrospective cohort study linked CAF administrative data to national cancer registries. Primary cancer diagnoses were ascertained from 1976 to 2017. Using age, year and sex-specific rates from the CGP, SIRs and 95% CIs were calculated by sex for all cancers combined and specific cancer types. Subgroup analyses were conducted for service status, rank and international deployment.

Results: Among 210 910 male and 34 940 female CAF personnel and Veterans, 6415 and 1620 incident primary cancer cases were observed, respectively. For cancers overall, CAF personnel and Veterans had lower or similar risk compared with the CGP. Subgroup analyses indicated lower or similar risk compared with the CGP for most cancer types but elevated risk for melanoma in male and female personnel, officers, deployers and male senior non-commissioned members (NCMs); lung and bronchus cancer in male and female junior NCMs; pancreatic cancer in male junior NCMs; testicular cancer in male officers; and cervical cancer in female junior NCMs and non-deployers.

Conclusion: CAF personnel and Veterans had lower or equal rates of cancer overall compared with the CGP. Elevated rates were observed for certain cancers within subgroups. Further research to examine time trends and risk factors for cancer outcomes in this population is recommended.