An Update on Cancer in American Indians and Alaska Natives, 1999-2004 Supplement to Cancer Cancer in American Indian and Alaska Native Young Adults (Ages 20–44 Years): US, 1999–2004

BACKGROUND. An examination of cancer incidence patterns in American Indians and Alaska Native (AI/AN) young adults may provide insight into their present and future cancer burden. METHODS. To reduce racial misclassification, incidence data were linked with the Indian Health Service (IHS) patient services database. Age-adjusted cancer inci-dence rates per 100,000 (AAR) and corresponding rate ratios (RR) for young adults (ages 20-44 years) were compared across IHS regions and for selected can-cers within Contract Health Service Delivery Area counties by race (AI/AN vs non-Hispanic whites [NHW]) and sex. RESULTS. The all-sites cancer incidence rate was lower for AI/ANs (AAR of 83.8) than for NHWs (AAR of 111.2) (RR of 0.75) but varied by IHS regions. Among the leading cancers in AI/AN females the risk was elevated for stomach (RR of 3.22), colorectal (RR of 1.30), uterine (RR of 1.61), and kidney (RR of 1.39) cancers and was lower for breast (RR of 0.70) and thyroid (RR of 0.71) cancers. Among AI/AN young adult males the risk was elevated for stomach (RR of 2.62), liver (RR o