has the advantage of a good participation rate for the deployed veterans and use of criteria for assessing self-reports of health but is limited in that self-reports were not verified by a physical examination and the participation rate for the control group was poor. Although the veterans were asked about psychologic stressors experienced during their deployment, the results of this questionnaire were not correlated with specific health outcomes.
Three secondary studies also estimated the risk of skin cancer in Gulf War veterans on the basis of self-reports. As discussed above, the Iowa Persian Gulf Study Group (1997) also surveyed deployed and nondeployed Gulf War veterans from a restricted geographic area to ascertain the prevalence of skin cancer. Compared with nondeployed veterans, Gulf War veterans had a significantly increased prevalence rate difference for skin cancer (Cochran-Mantel-Haenszel rate difference 0.8, 95% CI 0.4-1.3, p ≤ 0.05).
In the Kang et al. (2000b) study, the population prevalence of self-reported skin cancer was estimated to be 1.5% in Gulf War veterans and 1.4% in Gulf War-era veterans for a statistically significant increased rate difference of 0.15 (95% CI 0.11-0.19, p ≤ 0.05). Steele (2000) looked at skin cancer in Gulf War-deployed and nondeployed Kansas veterans in 1998. On the basis of a structured telephone interview in which veterans were asked whether they had ever received a physician’s diagnosis of or treatment for a medical condition and when it had developed, the OR for skin cancer occurring after 1990 in deployed veterans was 1.17 (95% CI 0.47-2.90). As noted in the discussion of this study above, its limitations include a restricted geographic area, lack of verification of medical conditions by medical record or examination, and poor exposure data.
Few studies have assessed cancer in Vietnam War and Gulf War veterans who have PTSD. The committee identified only one primary study: Boscarino (2005) examined excess postservice mortality from cancer in Vietnam veterans by using data from the VES 16 years after the war. Mortality was assessed in Vietnam veterans who were known to be alive in 1983 and who completed a telephone interview at that time on PTSD symptoms and health status; 7924 Vietnam-theater and 7364 Vietnam-era veterans completed the telephone interview. Vital status was assessed for the period January 1985-December 2000 with the VA Beneficiary Identification Record Locator Subsystem (BIRLS) Death File, the Social Security Administration Death Master File, and the National Death Index Plus. Cause of death was coded according to ICD. During the telephone interview, veterans were asked about 15 PTSD-related symptoms and their frequency; in 1985-1986, PTSD was diagnosed in a subsample of the veterans (2490 theater veterans and 1972 era veterans) on the basis of personal interviews with the Diagnostic Interview Schedule Version III (DIS-III). With DIS-III, 377 veterans were diagnosed with lifetime PTSD on the basis of combat exposure, which was assessed with the Combat Exposure Scale. Boscarino reported that in the telephone interview there was a clear dose-response relationship between low, moderate, high, and very high combat exposure and whether the criteria for PTSD were met. The Cox proportional-hazards ratio for cancer mortality (188 total deaths) was 1.9 for PTSD-positive Vietnam-theater veterans (95% CI 1.1-3.3, p = 0.018) and 0.9 (95% CI 0.3-3.1) for Vietnam era veterans with the model adjusted for race, Army volunteer status, Army entry age, Army discharge status, Army illicit drug use, age at interview, intelligence, and pack-years of cigarette-smoking. Strengths of this study include a large sample, a sufficient latent period (17 years) for death from cancer, the use of an in-person structured interview to diagnose PTSD, and an assessment of combat exposure; limitations include lack of specification as to cancer type.