The Elevated Risk of Ovarian Clear Cell Carcinoma among Asian Pacific Islander Women in the United States is Not Affected by Birthplace

Objective. To determine incidence of ovarian clear cell cancer (OCCC) by race ethnicity and how that relationship is affected by birthplace among Asian Pacific Islanders (API). Methods. The 18 registries of the U.S. Surveillance, Epidemiology, and End Results (SEER) dataset were queried to identify all women registered with epithelial ovarian cancer from 1973 to 2013. Relative risks of OCCC to non-OCCC based on ethnicity and birthplace were compared. Results. We identified 72, 501 women with epithelial ovarian cancer in the dataset; of these, 5078 (7.0%) had OCCC and 4859 (6.7%) were API. The age-adjusted incidence rate/100,000 women of OCCC was significantly higher in API women (0.6, 0.5-0.6 95% CI) compared to any other ethnicity. A significantly higher proportion of API women had OCCC (14.5%) compared to their White (6.6%, RR 2.2, p < 0.0001) and Black counterparts (4.3%, RR 3.4, p < 0.0001). The majority of API women were foreign-born (70.8%). The relative risk of clear cell compared to non-clear cell epithelial ovarian cancer was not demonstrably different among foreign born API women with ovarian cancer (RR 1.1, 95% CI 0.9 to 1.3, p = 0.6). Conclusions. We have demonstrated that, in the US, there is an elevated risk of OCCC associated with API ethnicity. Place of birth does not appear to significantly modify the association, suggesting that the increased risk of OCCC in API women may not be affected by acculturation or environmental exposure. Future research exploring the complex relationships between ethnicity and risk of malignancy will be important as we make progress in understanding disease process and treatment. (C) 2020 Elsevier Inc. All rights reserved.