Cancer Incidence in Montana: Rates for American Indians Exceed Those for Whites Original Research Article

Objectives Previous studies suggested that the cancer incidence rates in American Indians and Alaska Natives were lower than in other groups. The objective of this study was to compare the cancer incidence rates in American Indians and whites in Montana. Methods Age-adjusted 6-year cancer incidence rates were calculated for American-Indian and white men and women in Montana to allow comparison of rates in 1991–1996 to those in 1997–2002. Results The age-adjusted rates for American-Indian men were significantly higher than those for white men for all cancer sites (755 ± 74 [95% confidence interval] per 100,000 vs 544 ± 9 per 100,000), lung cancer (167 ± 35 per 100,000 vs 83 ± 4 per 100,000), and colorectal cancer (115 ± 29 per 100,000 vs 61 ± 4 per 100,000) from 1997 to 2002. The adjusted rates for American-Indian women were significantly higher than those for white women for all cancer sites (526 ± 47 per 100,000 vs 412 ± 8 per 100,000) and lung cancer (120 ± 24 per 100,000 vs 56 ± 3 per 100,000) during this same time period. There was a significant increase in the age-adjusted rates for all cancer sites among white men and women but not for American-Indian men or women between 1991–1996 and 1997–2002. Conclusions There is a significant disparity in the cancer incidence rates between American Indians and whites in Montana. Regional or state-level surveillance data will be needed to describe the changing patterns of cancer incidence in many native communities in the United States.