Background: Previous descriptive studies have suggested an increased risk of testicular carcinoma in military aviators. The association between testicular carcinoma and aviation in the U.S. Air Force was measured using a case-control study design.
Methods: A Department of Defense hospitalization database was used to obtain a set of testicular carcinoma cases (seminomas, embryonal cell carcinomas, teratocarcinomas, and choriocarcinomas) and an unmatched set of male appendicitis controls from October 1988 to February 1999. A centralized U.S. Air Force personnel database was used to obtain demographic and flying history data on the subjects. Multiple logistic regression was used to obtain odds ratios (OR) and confidence intervals (CI) for the following exposure factors: total flight time, rank, crew position, and general type of aircraft. Study subjects were restricted to white active duty officers.
Results: For one or more total flight hours, the age-adjusted OR was 1.74 (95% CI 1.04-2.92). Age-adjusted OR's for 1-499, 500-1999, and 2000 or more flight hours were, respectively, 1.37, 1.92, and 1.67. These OR's were not statistically significant. Age- and flight hour-adjusted OR's were increased for the navigator crew position and for bomber/tanker/ transport/reconnaissance type aircraft (2.13 and 1.67, respectively), but the ratios were not statistically significant. OR's were not increased for senior rank, fighter/trainer type aircraft, and rotary-wing aircraft.
Conclusions: There is an association between testicular carcinoma and flight time in U.S. Air Force officers. There was a suggestion of a dose-response effect; however, the OR's were not statistically significant.