Cancer survival among American Indians in western Washington state (United States)

Cancer survival among American Indians is worse than among other races in some regions of the United States, but has not been studied among American Indians in Washington state. Our purpose was to evaluate cancer survival among American Indians included in the Seattle-Puget Sound Cancer Registry. We compared site-specific survival among American Indians (n=551) and Whites (n=110,899) diagnosed from 1974 to 1989 for five cancer sites. For all sites except prostate, the distribution of cancer stage at diagnosis for American Indians was not significantly different from the distribution for Whites, and a similar proportion of American Indians and Whites received cancer treatment. After adjustment for age differences between American Indians and Whites, American Indians experienced poorer survival from prostate, breast, cervical, and colorectal cancer. Poorer survival among American Indians persisted after adjustment for differences in cancer stage at diagnosis, lack of cancer treatment, and residence in a non-urban county. The survival experience among American Indians who were recorded as non-American Indians in the cancer registry but whe were listed as American Indians in Indian Health Service records was more favorable than that among persons initially coded as American Indians in the cancer registry. We conclude that cancer survival among American Indians in western Washington is poorer than that among Whites in the same region, and that factors other than age, differences in stage at diagnosis, lack of cancer treatment, and residence in non-urban counties account for this.