Cancer Disparities Among Alaska Native People

INTRODUCTION: Cancer incidence rates have dramatically increased during the last 40 years. A disparity in overall cancer incidence exists between AN people and US whites.

METHODS: Data are from the Surveillance, Epidemiology and End Results (SEER) Alaska Native Tumor Registry, a population-based registry which includes AN people living in Alaska at the time of cancer diagnosis from 1969 to 2011. US white cancer incidence rates are from SEER*Stat. Statistical significance between AN and US white rates was determined through comparison of 95% confidence intervals (Tiwari modification).

RESULTS: Over the 43 year period, the age-adjusted incidence rate for all sites combined increased 32 percent. Incidence rates in AN men are similar to US white men (rate ratio = 1.0); however, AN women show rates that are 30% higher than US women for all cancers combined. Declines in cancer incidence rates that began in earlier years among US whites are now occurring in AN people during the most recent five-year period 2007-2011: all sites combined (AN men), colorectal (AN men and women), and lung (AN men). Declines in US rates of breast and lung cancer are not seen in incidence rates of AN women. Incidence rates in AN people which exceed US white rates for the period 2007-2011 are: all sites combined (AN:US rate ratio = 1.2), nasopharynx (11.3), gastric (3.3), colorectal (2.1), pancreas (1.4), lung (1.5) and kidney (1.6). Cancer incidence rates are lower in AN people than US whites for: melanoma (AN:US rate ratio =0.1), uterine (0.6), prostate (0.5) and thyroid cancer (0.7), and lymphoma (0.6).

CONCLUSIONS: Declines in lung cancer among AN men may indicate progress made through tobacco prevention and control program interventions established for tribal health organizations. Increases in colorectal screening may explain recent declines in colorectal cancer seen in recent years among AN people.