Impact of hysterectomy and bilateral oophorectomy prevalence on rates of cervical, uterine, and ovarian cancer among American Indian and Alaska Native women, 1999-2004

Objective To present more accurate incidence rates of cervical, uterine, and ovarian cancer by geographic region in American Indian/Alaska Native (AI/AN) women. Methods The authors used data from central cancer registries linked to Indian Health Service (IHS) patient registration database, the Behavioral Risk Factor Surveillance System, IHS National Data Warehouse, and the National Hospital Discharge Survey. Cancer incidence rates were adjusted for hysterectomy and oophorectomy prevalence and presented by region for non-Hispanic White (NHW) and AI/AN women. Results AI/AN women had a higher prevalence of hysterectomy (23.1%) compared with NHW women (20.9%). Correcting cancer rates for population-at-risk significantly increased the cancer incidence rates among AI/AN women: 43% for cervical cancer, 67% for uterine cancer, and 37% for ovarian cancer. Risk-correction led to increased differences in cervical cancer incidence between AI/AN and NHW women in certain regions. Conclusions Current reporting of cervical, uterine, and ovarian cancer underestimates the incidence in women at risk and can affect the measure of cancer disparities. Improved cancer surveillance using methodology to correct for population-at-risk may better inform disease control priorities for AI/AN populations.