had ever had a diagnosis or treatment by a physician for any of 16 specific medical conditions or for any medical conditions in five general categories and, if so, when the conditions had developed. Deployed veterans were also asked whether they had been notified by DoD about being in the area of the Khamisiyah munitions demolition. Cancers, other than skin cancer, were diagnosed after 1990 in 1% each of deployed and nondeployed veterans for a nonsignificant risk of 1.21 (95% CI 0.40-3.69), adjusted for sex, age, income, and education level.
Kang and Bullman (2001) studied causes of postwar mortality in Gulf War veterans through 1997. They ascertained vital status of a stratified random sample of Gulf War-deployed veterans and nondeployed veterans from VA and Social Security Administration databases, and death certificates were obtained from VA and the National Death Index database. From 1990 to 1997, there were 4506 deaths among 621,902 Gulf War veterans, and causes of death were obtained for 94.7% of them. The OR for mortality from any cancer during this period was 0.90 (95% CI 0.81-1.01) in men and 1.11 (95% CI 0.78-1.57) in women adjusted for age, race, branch of service, unit component, and marital status. The main strength of this study was the large sample. As in previous studies of Gulf War veterans, the latent period for most cancers is too long for their manifestation during the study period, and there was also a lack of information on risk factors.
Several secondary studies also looked at the prevalence of any cancer in Gulf War veterans. Eisen et al. (1991) and Proctor et al. (2001) examined U.S. veterans, Simmons et al. (2004) surveyed a large cohort of UK veterans, Goss Gilroy Inc. (1998) surveyed all Canadian Gulf War veterans, and O’Toole et al. (1996b) surveyed the entire Australian cohort of Gulf War veterans. Each of those studies found no significant increases in any cancer, on the basis of self-reports, in veterans deployed to the gulf compared with nondeployed veterans.
Two studies have focused specifically on testicular cancer. Testicular cancer is relatively uncommon in the United States. The annual age-adjusted incidence is 5.3 cases per 100,000 men. However, it is one of the few cancers whose usual age of onset is in the same range as the age of the Gulf War veterans, about 20-44 (Ries et al. 2005).
Knoke et al. (1998) examined testicular cancer in 517,223 deployed and 1,291,323 nondeployed male veterans on active duty during the time of the Gulf War. The authors identified cases of all first hospital admissions, in U.S. military hospitals worldwide, for a principal diagnosis of testicular cancer. Cases were identified by examining the DoD hospitalization database through April 1, 1997. A total of 505 cases were ascertained: 134 in the deployed and 371 in the nondeployed. In Cox proportional-hazards models adjusted for race and ethnicity, age, and occupation, no association with deployment status was observed (RR 1.05, 95% CI 0.86-1.29). The deployed did have an increased risk in the early months after the end of the deployment period. The initial increase in risk was originally reported in a study of all hospitalizations in the cohort by Gray et al. (1996) discussed above. However, by the end of 1996, the cumulative probability of hospitalization of the two groups was the same (0.034% for deployed and 0.035% for nondeployed). There was no interaction between covariates and deployment status. The authors also assessed the association of testicular cancer with specific occupations for both deployed and nondeployed veterans. The highest RRs were observed for men engaged in electronic-equipment repair (RR 1.56, 95% CI 1.23-2.00), construction-related trades (RR 1.42, 95% CI 0.93-2.17), and electric or mechanical repair (RR 1.26, 95% CI 1.01-1.58). The followup period was short for a cancer assessment, but it did include the age range