Incidence of primary liver cancer in American Indians and Alaska Natives, US, 1999-2009

To evaluate liver cancer incidence rates and risk factor correlations in non-Hispanic AI/AN populations for the years 1999-2009. We linked data from 51 central cancer registries with the Indian Health Service patient registration databases to improve identification of the AI/AN population. Analyses were restricted to non-Hispanic persons living in Contract Health Service Delivery Area counties. We compared age-adjusted liver cancer incidence rates (per 100,000) for AI/AN to white populations using rate ratios. Annual percent changes (APCs) and trends were estimated using joinpoint regression analyses. We evaluated correlations between regional liver cancer incidence rates and risk factors using Pearson correlation coefficients. AI/AN persons had higher liver cancer incidence rates than whites overall (11.5 versus 4.8, RR = 2.4, 95% CI 2.3-2.6). Rate ratios ranged from 1.6 (Southwest) to 3.4 (Northern Plains and Alaska). We observed an increasing trend among AI/AN persons (APC 1999-2009 = 5%). Rates of distant disease were higher in the AI/AN versus white population for all regions except Alaska. Alcohol use (r = 0.84) and obesity (r = 0.79) were correlated with liver cancer incidence by region. Findings highlight disparities in liver cancer incidence between AI/AN and white populations and emphasize opportunities to decrease liver cancer risk factor prevalence.