The incidence and mortality of prostate cancer are considerably higher in African American men compared to Caucasian men, and yet the factors contributing to these disparities are unclear. Researchers have considered whether changing the protocol for active surveillance in African American men with low risk prostate cancer may help bridge the disparities.
During Monday morning’s Next Frontier plenary session, Isaac Yi Kim, MD, PhD, said institutional bias and genetic variability associated with neuroendocrine features may play a role in the disparities, but there are not enough data at this time to support modifying active surveillance criteria based on race.
“For all of us as clinicians, this racial disparity issue comes to light when we are faced with an African American patient who comes to our clinic with newly diagnosed prostate cancer considering active surveillance,” said Dr. Kim, associate professor and Acting Chief of the Division of Urology at the Rutgers Robert Wood Johnson Medical School and Chief of the Section of Urologic Oncology at Rutgers Cancer Institute of New Jersey.
Research shows that the incidence rate of prostate cancer is 1.7-fold higher in African American men compared to Caucasian men, and the mortality rate is as much as 2.27-fold higher. Research also indicates that African American men who meet the active surveillance criteria are more likely than Caucasian men to have their disease up staged or upgraded after radical prostatectomy. African Americans also are more likely to have positive surgical margins and adverse pathological features.
However, most of the research in this area was conducted at single institutions and produced inconsistent results.
Dr. Kim’s research team considered data from seven institutions and found that of men who underwent radical prostatectomy, African American men were more likely than Caucasian men to have positive surgical margins and biochemical occurrence. However, when they stratified risk based on the institutions, they found the difference was due to one institution’s data. After removing that data, no disparity was found among the data from the remaining institutions.
“There appears to be significant inter-institutional variations in racial disparity,” Dr. Kim said. “I urge each institution to go back home and take at look at your data and see what they really show. I think a lot of the impressions we have about racial disparity may be based on a bias from one or two institutions.”
Dr. Kim’s research did not discount the possibility that genetic variability exists between races, he noted.
Dr. Kim and his colleagues crossed the gene set at his institution with all of the databases in the Cancer Genome Atlas. This research showed that neuroendocrine prostate cancer had high correlation and was highly altered in the set of genes identified at his institution.
“What this is suggesting to us is that, in fact, the genetic variation detected in African American patients may be associated with a more aggressive phenotype or from metastasis,” said Dr. Kim, noting that large-scale genetic risk studies are needed to produce more definitive results.