Researchers have uncovered a potential biological factor that may contribute to disparities in prostate cancer incidence and mortality between African-American and non-Hispanic white men in the United States, according to results presented here at the Sixth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved, held Dec. 6-9.
In the United States, African-American men are 1.5 times more likely to develop prostate cancer and more than twice as likely to die from the disease compared with non-Hispanic white men.
"The causes of prostate cancer disparities are numerous, complex, often interrelated, and only partially understood," said David P. Turner, Ph.D., assistant professor in the Department of Pathology and Laboratory Medicine at the Medical University of South Carolina in Charleston. "We have identified a potential relationship between sugar-derived metabolites and cancer that may provide a biological link with socioeconomic and environmental factors known to contribute to prostate cancer disparities.
"As our bodies use the sugars that we consume for energy they generate waste products, or metabolites, including molecules called advanced glycation end products, or AGEs," Turner explained. "AGEs naturally accumulate in our tissue as we grow older, and they have been implicated in diseases associated with aging such as diabetes, heart disease, and Alzheimer's disease. They can also cause increased inflammation and the generation of potentially harmful chemicals known as reaction oxygen species, which both promote cancer.
"Critically, a common source of the AGEs that accumulate in our bodies is the foods we eat, which has significant implications for cancer health disparities and our overall health.
"We found that AGE levels were highest in African-American men with prostate cancer," said Turner. "Because obesity, poor eating habits, and an inactive lifestyle all promote AGE accumulation, and these factors are often more evident in African-Americans, we hypothesize that there is a link between these factors that could help explain why African-American men are more likely to develop prostate cancer and die from the disease."
Turner and colleagues examined circulating and intratumoral AGE levels in 16 African-American and 16 non-Hispanic white men with prostate cancer. They found that AGE levels were higher in serum from cancer patients compared with individuals without cancer. When analyzing AGE levels in prostate tumor samples, levels were highest in tumor samples from African-American patients. In addition, AGE levels in prostate tumors correlated with levels of a molecule to which AGEs bind to mediate their effects, called receptor for AGE (RAGE).
"We think that the AGE-RAGE signaling pathway promotes prostate cancer and that increased AGE accumulation may represent a biological mechanism promoting prostate cancer disparity," said Turner.
This study was funded in part by the National Institutes of Health as part of the South Carolina Cancer Disparities Research Center. Turner declares no conflicts of interest.
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