Incidence Rates of Gynecologic Cancers in the U.S. Active Duty Military Population

Despite an increasing number of female service members, incidence rates of gynecologic cancers (other than cervical cancer) have not been previously documented in the U.S. active duty military population. This study sought to determine the incidence rates of all gynecologic, including peritoneal, malignancies in the U.S. Active Duty population compared to the general US population as reported in the Surveillance, Epidemiology, and End Results Program database.

Gynecologic cancers diagnosed in U.S. Active Duty women aged 20-59 between 2004 and 2013 were retrospectively ascertained. Cancer cases were identified in both the Automated Central Tumor Registry and the Military Health System Data Repository. All cases in Automated Central Tumor Registry plus cases recorded in Military Health System Data Repository, but not duplicative of Automated Central Tumor Registry cases, were included. Age-specific and age-adjusted incidence rates were calculated in military and Surveillance, Epidemiology, and End Results cases.

In U.S. Active Duty women, 327 incident cases of gynecologic cancer were identified. There were 110 cases of cervical cancer, 40 cases of endometrial cancer, 152 cases of ovarian cancer, and 25 other gynecologic malignancies. Of the 327 cases, 154 were ascertained from the Automated Central Tumor Registry database and the remainder from Military Health System Data Repository claims data. The age-adjusted rate of all gynecologic cancers for U.S. Active Duty women was 49.17 per 105 (95%CI 37.58, 65.12), while the age-adjusted rate for Surveillance, Epidemiology, and End Results -18 was 42.09 per 105 (95%CI 41.83, 42.35). The kappa coefficient assessing the overlap between the data sources was -0.1937. Though insufficient in numbers for statistical analysis, the observed proportion of ovarian to cervical cancer cases in active duty women < 45 years of age was substantially greater than in the general population.

U.S. Active Duty women exhibited a similar age-adjusted rate of gynecologic cancer as the general US population. There was suboptimal overlap between the Automated Central Tumor Registry and Military Health System Data Repository databases, indicating the necessity of using both databases in order to obtain reliable data in the active duty population. This study is the current best estimate of a baseline rate of gynecologic cancer in U.S. active duty military women. This rate might change over time as women's roles and exposures in recent and future military conflicts evolve.