Disparities in incidence and trends of colorectal, lung, female breast, and cervical cancers among non-Hispanic American Indian and Alaska Native people, 1999-2018

Abstract

Purpose: This study is the first to comprehensively describe incidence rates and trends of screening-amenable cancers (colorectal, lung, female breast, and cervical) among non-Hispanic AI/AN (NH-AI/AN) people.

Methods: Using the United States Cancer Statistics AI/AN Incidence Analytic Database, we, calculated incidence rates for colorectal, lung, female breast, and cervical cancers for NH-AI/AN and non-Hispanic White (NHW) people for the years 2014-2018 combined. We calculated age-adjusted incidence rates (per 100,000), total percent change in incidence rates between 1999 and 2018, and trends over this time-period using Joinpoint analysis. Screening prevalence by region was calculated using Behavioral Risk Factor Surveillance System data.

Results: Rates of screening-amenable cancers among NH-AI/AN people varied by geographic region and age at diagnosis. Over half of all lung and colorectal cancers in NH-AI/AN people were diagnosed at later stages. Rates of lung and colorectal cancers decreased significantly between 1999-2018 among NH-AI/AN men, but no significant changes were observed in rates of screening-amenable cancers among NH-AI/AN women.

Conclusion: This study highlights disparities in screening-amenable cancers between NH-AI/AN and NHW people. Culturally informed, community-based interventions that increase access to preventive health services could reduce cancer disparities among AI/AN people.

Keywords: Alaska Native; American Indian; Cancer incidence; Health disparity; Screening; Trends.

Fig. 1

Total percent change and average annual percent change for screening-amenable cancer rates^a among non-Hispanic AI/AN^b and non-Hispanic White women and men, 1999 to 2018, PRCDA Counties, United States. PRCDA indicates Purchased/Referred Care Delivery Area; AI/AN: non-Hispanic American Indian/Alaska Native; NHW: non-Hispanic White RR, Rate Ratio Source: National Program of Cancer Registries and Surveillance, Epidemiology, and End Results SEER*Stat Database: U.S. Cancer Statistics American Indian and Alaska Native Incidence Analytic Database—1998–2018. United States Department of Health and Human Services, Centers for Disease Control and Prevention. Released June 2021, based on the 2020 submission. States that have at least one PRCDA-designated county, grouped by Indian Health Service (IHS) region are: Alaska (Alaska), Pacific Coast (California, Idaho, Oregon, and Washington), Southwest (Arizona, Colorado, Nevada, New Mexico, and Utah), Northern Plains (Indiana, Iowa, Michigan, Minnesota, Montana, Nebraska, North Dakota, South Dakota, Wisconsin, and Wyoming), Southern Plains (Kansas, Oklahoma, and Texas), and East (Alabama, Connecticut, Florida, Louisiana, Massachusetts, Maine, Mississippi, New York, North Carolina, Pennsylvania, Rhode Island, South Carolina, and Virginia). The percentage of the American Indian/Alaska Native population living in a PRCDA-designated county from 2014–2018 was 53.3% for the United States; by IHS region, these percentages were: Alaska=100%; Pacific Coast=60.3%; Southwest=83.9%; Northern Plains=54.3%; Southern Plains=56.7%; and East=16.8%. ^aRates are per 100,000 people and are ageadjusted to the 2000 U.S. standard population (19 age groups - Census P251130). ^bAI/AN race is reported by NPCR and SEER registries or through linkage with the IHS patient registration database. Includes only AI/AN of nonHispanic origin. ^cThe change in rates was calculated as the total percentage change from the rate in 1999 to the rate in 2018. ^dAAPC represents average annual percent change in rates between 1999 and 2018, calculated using joinpoint regression. *Indicates AAPC is statistically significantly different from zero (2-sided p<0.05)