Simmons et al. (2004) conducted a retrospective cohort study of male UK Gulf War deployed veterans (n = 23,358) and a comparable cohort of nondeployed veterans (n = 17,730) for self-reported health outcomes. Among the deployed veterans, 127 cancer cases, including malignant neoplasms and brain tumors were reported, compared to 88 among the nondeployed veterans (OR 1.1, 95% CI 0.9-1.5).
Finally, the Update committee identified two new secondary studies with information on cancer outcomes. From 1994 to 1996, Proctor et al. (2001a) evaluated health-related quality of life among 141 Gulf War deployed veterans and 46 veterans deployed to Germany, selected from active-duty, reserve and National Guard troops deployed through Fort Devens, Massachusetts. Among the Gulf War deployed veterans and the Germany deployed participants, 2.1% and 4.4% respectively, reported cancer, excluding skin cancer. In 2005, Kang and colleagues published a follow-up survey of the sample (15,000 deployed and 15,000 nondeployed US Gulf War veterans) described in the earlier study (Kang et al., 2000, 2009). Among the 6111 deployed and 3859 era veterans who responded, 1160 reported skin cancer diagnoses and 990 reported “other cancer.” The risk ratios, adjusted for age, sex, race, body mass index, current cigarette smoking, rank, branch of service, and unit component, for skin cancer and other cancer were 1.09 (95% CI 0.97-1.22) and 1.09 (95% CI 0.96-1.24), respectively.
There is no consistent evidence of a higher overall incidence of cancer in veterans who were deployed to the Gulf War than in nondeployed veterans. An association of brain-cancer mortality with possible nerve-agent exposure (based on the 2000 DoD exposure model) was observed in one study discussed in Volume 4 (Bullman et al., 2005), and the association holds up with an additional 4 years of follow-up in the same cohort (Barth et al., 2009). The association with exposure to smoke from oil-well fires became stronger with further follow-up. However, the numbers of cases of brain cancer who had possibly been exposed to nerve agents as a result of the Khamisiyah explosion was small, and there is little previous evidence of an association of sarin or organophosphate pesticides with brain cancer. Therefore, the committee concluded that there was insufficient/inadequate evidence of an association between Gulf War exposures and brain cancer. Mixed results for testicular cancer were reported by the Volume 4 committee; however, the Update committee did not identify any new studies of this cancer site. In general, many veterans are still too young for cancer diagnoses, and for most cancers the follow-up period after the Gulf War is probably too short to expect the onset of cancer. Therefore, the committee believes that further follow-up is necessary to be able to make a conclusion about whether there is an association between deployment during the Gulf War and cancer outcomes.
The committee concludes that there is insufficient/inadequate evidence of an association between deployment to the Gulf War and any cancer.
Recommendation: Due to the long latency period for cancer, there needs to be continued follow-up of Gulf War veterans and an appropriate comparison group to adequately determine any association.