Objective: The purpose of this study was to examine trends of ovarian cancer in California. Known risk factors for ovarian cancer are unequally distributed across different cultures. California, the most ethnically diverse State in the U.S., is uniquely positioned to detect trends in different race/ethnic groups.
Methods: This study was based on ovarian cancer cases and deaths occurring between 1990 and 2003 and reported to the California Cancer Registry (CCR). Age-adjusted rates were calculated by race/ethnicity, age at diagnosis, tumor behavior, and morphology. Trends were evaluated using the annual percent change, estimated through joinpoint regression.
Results: The study population included 30,669 invasive ovarian cancers, 5925 tumors of borderline malignancy, and 19,719 ovarian cancer deaths. Age-adjusted incidence rates of invasive ovarian cancer per 100,000 women decreased from 15.6 in 1990 to 12.9 in 2003, a statistically significant decline of 1.3% per year. Rates of epithelial malignancies declined in all age groups examined, with the largest decreases noticed among women 65-74 years old. Substantial differences in trends were detected by race/ethnicity. Epithelial malignancies declined significantly among non-Hispanic black and white women by 2.5% and 1.2% per year, respectively. Changes among Asian/Pacific Islander and Hispanic women were smaller and non-significant. Ovarian cancer mortality rates did not change significantly during the study period.
Conclusions: The incidence of epithelial ovarian cancer in California declined significantly among all age groups examined and among non-Hispanic white and black women. Among Hispanic and Asian/Pacific Islander women, declines were small and non-significant.