Characterizing Cancer Burden in the American Indian Population in North Carolina

Background: The American Indian (AI) population in North Carolina has limited access to the Indian Health Service. Consequently, cancer burden and disparities may differ from national estimates. We describe the AI cancer population and examine AI-White disparities in cancer incidence and mortality.Methods: We identified cancer cases diagnosed among adult AI and White populations between 2014 and 2018 from the North Carolina Central Cancer Registry. We estimated incidence and mortality rate ratios (IRR and MRR) by race. In addition, between the AI and White populations, we estimated the ratio of relative frequency differences [RRF, with 95% confidence limits (CL)] of clinical and sociodemographic characteristics. Finally, we evaluated the geographic distribution of incident diagnoses among AI populations.Results: Our analytic sample included 2,161 AI and 204,613 White individuals with cancer. Compared with the White population, the AI population was more likely to live in rural areas (48% vs. 25%; RRF, 1.89; 95% CL, 1.81-1.97) and to have Medicaid (18% vs. 7%; RRF, 2.49; 95% CL, 2.27-2.71). Among the AI population, the highest age-standardized incidence rates were female breast, followed by prostate and lung and bronchus. Liver cancer incidence was significantly higher among the AI population than White population (IRR, 1.27; 95% CL, 1.01-1.59). AI patients had higher mortality rates for prostate (MRR, 1.72; CL, 1.09-2.70), stomach (MRR, 1.82; 95% CL, 1.15-2.86), and liver (MRR, 1.70; 95% CL, 1.25-2.33) cancers compared with White patients.Conclusions: To reduce prostate, stomach, and liver cancer disparities among AI populations in North Carolina, multi-modal interventions targeting risk factors and increasing screening and treatment are needed.Impact: This study identifies cancer disparities that can inform targeted interventions to improve outcomes among AI populations in North Carolina.