Cancer survival disparities for most minority populations increase as cancers become more treatable

The findings, published in the October 2009 issue of Cancer Epidemiology, Biomarkers, and Prevention, highlight the need to develop specific health policies and interventions to address social disparities.

Although prior studies have focused on factors that contribute to disparities in specific cancers, the Mailman School researchers' goal in this study was to understand why racial/ethnic disparities emerge in some cancers but not others. The study used data from more than 580,000 cancer cases in the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) registries to compare racial/ethnic differences in survival across a spectrum of cancers, classified according to their five-year relative survival rates as a measure of how amenable each cancer is to medical interventions. The authors hypothesized that racial/ethnic disparities increase as medical interventions improve overall survival because individuals with more socioeconomic resources are in a better position to exploit medical advances to protect their health.

The results found that, as compared with whites, substantial survival disparities existed in more treatable cancers in African-Americans, American Indians/Alaska Natives, Hispanics, and several subgroups of the Asian/Pacific Islander population.

"Our findings may seem counterintuitive at first since medical advances in the last few decades have resulted in substantial improvements in cancer survival for most racial/ethnic population groups. However, this enhanced capacity to successfully treat certain cancers, when combined with the social disadvantage faced by many minorities, can lead to greater relative differences in cancer survival by race and ethnicity," said Parisa Tehranifar, DrPH, assistant professor of Epidemiology, a member of the Herbert Irving Comprehensive Cancer Center (HICCC) at Columbia University Medical Center/NewYork-Presbyterian Hospital and the Mailman School of Public Health's Center for the Study of Social Inequalities in Health and lead author of the paper.

"If we are correct in our interpretation that these disparities emerge as a result of greater utilization of available interventions by socially advantaged groups, it follows that interventions that are easy to access and use, and do not rely heavily on personal resources such as educational and income levels, may have the greatest potential for reducing cancer and other health disparities," noted Dr. Tehranifar.

"Our cancer prevention and treatment efforts should continue to advance our public health and medical capacity for lowering the burden of cancer and mortality. However, we must also pay close attention to how the benefits of our medical advances are distributed in the population, and implement specific strategies that can reduce cancer disparities," said Mary Beth Terry, PhD, associate professor of Epidemiology, a co-leader of the Cancer Epidemiology Program at the Herbert Irving Comprehensive Cancer Center (HICCC) at Columbia University Medical Center/NewYork-Presbyterian Hospital, and senior author of the paper.

Supported by a Lance Armstrong Foundation Young Investigator Award and a postdoctoral fellowship from the National Cancer Institute, the research was done in collaboration with: Dr. Alfred I. Neugut, MD, PhD; Myron Studner Professor of Cancer Research in the Department of Medicine and professor of Epidemiology, and leader of the Prevention, Control & Disparities Program at the Herbert Irving Comprehensive Cancer Center (HICCC) at Columbia University Medical Center/NewYork-Presbyterian Hospital; Jo C. Phelan, PhD, associate professor of Sociomedical Sciences; and Bruce G. Link, PhD, professor of Sociomedical Sciences and Epidemiology. Drs. Phelan and Link are also co-directors of Mailman School's Center for the Study of Social Inequalities and Health.