Socioeconomic factors predominantly explain racial and ethnic disparities in prostate cancer outcomes, according to a new study. Published in the March 15, 2006 issue of Cancer, the study found that race plays a minor role in prostate cancer survival, and that the most important factors related were education, community poverty, and income levels. Age, disease stage, and treatment method also independently affected outcome.

Prostate cancer, generally a slow growing malignancy with a good prognosis, is one of the most common cancers in men. However, the incidence and mortality rates have been shown to be racially disparate, with African-Americans at particular risk of being diagnosed with more advanced disease and to die from the disease compared to Caucasians. Whether these differences are due to race or other factors, such as socioeconomic status and treatment, remain poorly explored.

Accounting for Survival Differences

Xianglin L. Du, phd, of the University of Texas School of Public Health at Houston, and colleagues reviewed up to 11 years of follow-up data from 61,228 men aged 65 years or older diagnosed with local or regional prostate cancer to further characterize the role of race in prostate cancer survival.

Disparities in survival were explained by socioeconomic factors, including level of education, level of poverty in the community, and income. Other conventional factors, such as advanced age, advanced stage of disease, the type of treatment, and greater number of comorbidities, were less strongly associated with poor survival. Race played little role in outcome. Confirming other reports, Hispanics had a lower risk compared to African-Americans and Caucasians after controlling for other factors. Mortality risk of African-Americans was all but negated after controlling for socioeconomic factors and tumor characteristics.

The researchers "found that in men with local or regional stage prostate cancer, lower socioeconomic status was significantly associated with decreased survival, even after controlling for other patient/tumor characteristics and treatment." In addition, the study identified "racial and ethnic disparities in survival, but these disparities reduced substantially after controlling for socioeconomic factors."