Gynecologic cancer incidence and mortality among American Indian/Alaska Native women in the Pacific Northwest, 1996-2016.

OBJECTIVES: Compare the incidence and mortality of gynecologic cancers among American Indian/Alaska Native (AI/AN) women to the Non-Hispanic White (NHW) population in the Pacific Northwest. METHODS: Age-adjusted cancer incidence (1996-2016) and mortality (2006-2016) rates were calculated from population-based state cancer registry and death certificate data obtained from Washington, Oregon, and Idaho, and corrected for AI/AN misclassification. Incidence and mortality rate ratios (RR) were calculated to compare AI/AN and NHW women with gynecologic cancers. RESULTS: Across all gynecologic cancer sites, AI/AN women were diagnosed at a younger age compared to NHW women. AI/AN women had a higher incidence of cervical cancer compared to NHW women with a RR of 1.53 (95% CI: 1.34, 1.75). For all age groups, AI/AN women had a higher incidence of cervical cancer and the disparity was greatest in the 50-64 age group with a RR of 1.76 (95% CI: 1.36, 2.30). Cervical cancer mortality was greater among AI/AN women, with an all-ages RR of 1.79 (95% CI: 1.30, 2.46); the disparity was greatest in the 50-64 age group (RR: 2.88, 95% CI: 1.89, 4.38). For uterine cancer, AI/AN women had similar incidence rates as NHW women but higher mortality rates (RR: 1.35, 95% CI: 1.03-1.75). Incidence and mortality for ovarian cancer were similar between groups. CONCLUSION: Our analysis of gynecologic cancers among AI/AN in the PNW found significant disparities relative to NHW women in cervical cancer incidence and mortality. These disparities persist despite advances in prevention strategies.