Testicular cancer and Persian Gulf War service

We studied whether regular, active-duty servicemen deployed to the Persian Gulf War were at increased risk of testicular cancer compared with nondeployed Gulf War-era servicemen from August 1991 through March 31, 1996, using a Cox proportional hazards model for survival analysis with covariates. Race was an important predictor of hospitalization for testicular cancer [rate ratio (RR) = 0.19; 95% confidence interval (CI) = 0.12-0.29 for blacks, and RR = 0.59; 95% CI = 0.39-0.91 for Hispanics, other, and unknown (combined), relative to whites]. Age effects were modest (RR = 1.19; 95% CI = 0.91-1.56 for those of ages 22-25 years, and RR = 1.24; 95% CI = 0.96-1.59 for those of ages 26-31 years, compared with those of ages 17-21 years). Risk also varied with occupation (RR = 1.56; 95% CI = 1.23-2.00 for those in electronic equipment repair; RR = 1.26; 95% CI = 1.01-1.58 for those in electrical/mechanical repair; and RR = 1.42; 95% CI = 0.93-2.17 for those in construction-related trades, compared with those in other occupations). Deployment status was not important (RR = 1.05; 95% CI = 0.86-1.29 for the deployed compared with the nondeployed). There was an increase in testicular cancer in the deployed group in the immediate postwar period that was consistent with a previous report of a standardized RR of 2.12; 95% CI = 1.11-4.02 (compared with the nondeployed group) in the last 5 months of 1991, but by 4 years after the end of deployment, the cumulative risks for the two groups were not different. An additional analysis suggested that the immediate postwar increase in the deployed was likely due to regression to the mean after a healthy serviceman selection effect for deployment and the deferment of care during deployment.