Background: The burden of cancer mortality falls disproportionately on cancer patients belonging to ethnic minority groups. In the U.S., African American, Hispanic, and American Indian cancer patients are diagnosed at a more advanced stage and receive less appropriate treatment, resulting in poorer outcomes and higher mortality, than white cancer patients. The authors hypothesized that cancer control strategies based on earlier detection and more effective treatment may be most effective in increasing survival in groups with more advanced disease at diagnosis, less appropriate treatment, and lower survival.
Methods: Data collected by the New Mexico Tumor Registry, a member organization of the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute, afforded the authors an opportunity to investigate this hypothesis by studying trends in cancer survival for American Indians, Hispanics, and non-Hispanic whites. The authors examined temporal trends and ethnic disparities in survival for in situ and invasive incident cancer cases at 25 sites diagnosed from 1969 through 1994 in New Mexico residents and in American Indians residing in Arizona.
Results: The distribution of stage became more favorable and the percentage of patients receiving appropriate treatment increased for all three ethnic groups during the study period. Survival improved for patients with cancer at most sites in each ethnic group; however, because the increase in survival was greater for non-Hispanic whites than for American Indians or Hispanics, the number of sites associated with disparities in survival among non-Hispanic whites, American Indians, and Hispanics increased. Differences in the distribution of age, gender, stage at diagnosis, histologic grade, and treatment did not completely explain the improved survival or the ethnic disparities regarding survival.
Conclusions: Increased cancer control efforts were associated with earlier diagnosis, more patients receiving appropriate therapy, and improved survival for non-Hispanic whites, American Indians, and Hispanics. However, the improvement was greatest for non-Hispanic whites, and disparities in survival results for the different ethnic groups widened over the period of study. Cancer control strategies need to address the specific social, cultural, and biologic prognostic factors that affect different ethnic groups if disparities in outcomes are to be reduced.