Espey, David K.

Abstract Background: Cancer incidence rates for American Indian and Alaska Native (AI/AN) populations vary by geographic region in the United States. The purpose of this study is to examine cancer incidence rates and trends in the AI/AN population compared with the non-Hispanic white population in the United States for the years 2010 to 2015. Methods: Cases diagnosed during 2010 to 2015 were identified from population-based cancer registries and linked with the Indian Health Service (IHS) patient registration databases to describe cancer incidence rates in non-Hispanic AI/AN persons compared with non-Hispanic whites (whites) living in IHS purchased/referred care delivery area counties. Age-adjusted rates were calculated for the 15 most common cancer sites, expressed per 100,000 per year. Incidence rates are presented overall as well as by region. Trends were estimated using joinpoint regression analyses. Results: Lung and colorectal cancer incidence rates were nearly 20% to 2.5 times higher in AI/AN males and nearly 20% to nearly 3 times higher in AI/AN females compared with whites in the Northern Plains, Southern Plains, Pacific Coast, and Alaska. Cancers of the liver, kidney, and stomach were significantly higher in the AI/AN compared with the white population in all regions. We observed more significant decreases in cancer incidence rates in the white population compared with the AI/AN population. Conclusions: Findings demonstrate the importance of examining cancer disparities between AI/AN and white populations. Disparities have widened for lung, female breast, and liver cancers. Impact: These findings highlight opportunities for targeted public health interventions to reduce AI/AN cancer incidence.

Objectives. We used improved data on American Indian and Alaska Native (AI/AN) ancestry to provide an updated and comprehensive description of cancer mortality and incidence among AI/AN populations from 1990 to 2009. Methods. We linked the National Death Index and central cancer registry records independently to the Indian Health Service (IHS) patient registration database to improve identification of AI/AN persons in cancer mortality and incidence data, respectively. Analyses were restricted to non-Hispanic persons residing in Contract Health Service Delivery Area counties in 6 geographic regions of the United States. We compared age-adjusted mortality and incidence rates for AI/AN populations with White populations using rate ratios and mortality-to-incidence ratios. Trends were described using joinpoint analysis. Results. Cancer mortality and incidence rates for AI/AN persons compared with Whites varied by region and type of cancer. Trends in death rates showed that greater progress in cancer control was achieved for White populations compared with AI/AN populations over the last 2 decades. Conclusions. Spatial variations in mortality and incidence by type of cancer demonstrated both persistent and emerging challenges for cancer control in AI/AN populations.