Recent declines in ovarian cancer incidence rates in the United States

A53 Introduction . Ovarian cancer is the deadliest gynecologic malignancy in the United States. Several studies have linked hormone replacement therapy (HRT) use with increased risk for ovarian cancer. Beginning in 2002, the United States Preventive Services Task Force (USPSTF) began recommending against use of HRT due to increased risk of breast cancer. Subsequently in 2003, significant decreases of about 6% were observed in breast cancer incidence rates in the United States. The aim of the current study is to examine recent ovarian cancer incidence rates in the United States to determine 1) if decreases in ovarian cancer similar to those found in breast cancer incidence occurred, and 2) if any decreases observed were temporally consistent with recommendations regarding decreased use of HRT. Methods . Cancer incidence data from registries affiliated with CDC’s National Program of Cancer Registries or the NCI’s Surveillance, Epidemiology and End Results programs meeting high quality criteria were used in this analysis; these data cover 86% of the U.S. population. Over 85,000 new cases of ovarian cancer diagnosed from 1999 to 2003 were included. Incidence rates, age adjusted to the 2000 U.S. standard, were calculated by year, race/ethnicity, 10 year age groups, and stage; significant differences in rates were tested using the rate ratio test. Results . Overall, from 1999-2001, ovarian cancer incidence rates were 13.0-13.1 per 100,000 women and were stable. In 2002, the ovarian cancer rate significantly decreased by 5.4% to 12.3 per 100,000 women (p Conclusions . The 5% decrease in ovarian cancer rates in 2002 is consistent with regard to the magnitude of the decrease observed in breast cancer rates. However, the ovarian cancer decrease preceded the breast cancer decrease and was not temporally consistent with the release of USPSTF recommendations. The smaller 2% decrease in ovarian cancer rates in 2003 may be related to USPSTF recommendations. More research is needed to determine the relationship between HRT use and ovarian cancer incidence rates. Research is also necessary to determine what may be driving these declines, whether subsequent declines in ovarian cancer mortality are also observed, and why some populations of women did not experience a decrease in ovarian cancer rates.