Military-specific factors and incident melanoma diagnoses among active duty participants in the millennium cohort study, 2000-2021.

Service members experience unique occupational hazards that may increase their risk for melanoma. This longitudinal study aimed to determine associations between deployment status, environmental exposures, and solar exposures and incident melanoma among active duty service members. Millennium Cohort Study survey data (2001-2021) were linked with deployment and military health care records (2000-2021). Adjusted Cox proportional hazards models estimated effects of exposures and covariates on incident melanoma. Risk of melanoma diagnosis by age (early vs late onset) and anatomical site (sun-protected vs sun-exposed skin) were also estimated. Among 115,512 service members, 184 were diagnosed with melanoma during the study period (61% were <40 years old and 77% diagnosed on sun-protected skin). Melanoma risk by demographics was consistent with civilian studies. Among this military population, those who deployed (adjusted hazard ratio [AHR] 0.55 [95% CI 0.40, 0.75]) had reduced melanoma risk. Conversely, those who self-reported being exposed to occupational hazards (AHR 1.43 [95% CI 1.05, 1.95]) had elevated melanoma risk. Findings were consistent with the "healthy deployer effect," while self-reported occupational hazards were associated with an increased risk of melanoma. Results may be informative for understanding melanoma etiology, risk counseling, and screening.