African American Prostate Cancer Patients Twice as Likely to Have More Aggressive Disease
Prostate cancer is the most common cancer among men in the United States. Many men with the disease have good outcomes during treatment and can live long, cancer-free lives. However, there are substantial cancer disparities with this disease. African American men, for example, tend to have more aggressive disease and poorer outcomes.
Physicians typically determine how aggressive a tumor is based on an examination of tissue samples of cancer cells. The tissue samples are graded on a scale according to their appearance with Grade group 1 (Gleason score 6 or less) being nonaggressive through Grade group 5 (Gleason score of 10) being most aggressive. Additional tests, such as bone, MRI and positron emission tomography scans, are also performed to determine whether the cancer has spread. But these tests do not always identify aggressive disease because they rely on features of the tumor cells and clinical factors, not on differences in tumor genomic patterns that are associated with poorer outcomes.
Moffitt Cancer Center has been part of a study determining if the Decipher Prostate Genomic Classifier can help accurately categorize risk and help physicians select the appropriate treatment plan for African American prostate cancer patients. Decipher is a 22-gene prognostic biomarker that provides a low, intermediate or high genomic score indicating the aggressiveness of a patient’s cancer. It was developed with a patient group that was predominantly white, though additional retrospective studies that analyzed historical data found that the test was able to determine genomic risk among African American men with similar predictive performance.
While the retrospective studies were promising, prospective studies that follow the outcomes of patients in real time are the gold standard. The Moffitt-led VANDAAM trial is the first prospective study to investigate the genomic biomarkers test in African American men with prostate cancer.
“This trial is crucial because there are few prospective studies that have focused on maximizing the recruitment of African American men to address this problem. It is important to identify those men who are at higher risk of poorer outcomes to improve treatment management and overall survival,” said Dr. Kosj Yamoah, principal investigator for this study and chair of Moffitt’s Radiation Oncology Department.
The VANDAAM trial enrolled men with low- or intermediate-risk prostate cancer. To help with accrual, Moffitt partnered with two Tampa Bay area veterans hospitals — James A. Haley Veterans’ Hospital and Bay Pines VA Healthcare System. Participants on this clinical study included 113 African American and 113 non-African American men.
Results from the study, recently published in the Journal of the National Cancer Institute, show that a higher proportion of African American men had higher Decipher scores compared to non-African American men. Men who self-identified as African American were more than twice as likely to be reclassified with higher risk disease based on results from their Decipher test scores. Another important finding was that younger African American men had higher Decipher scores, an indicator of aggressive disease. However, in non-African American men, scores indicating higher risk of disease spread was observed in older men.
“This study revealed some interesting observations that help us begin to understand how to address the disparities from multiple angles,” Yamoah said. “Allowing increased access to care is a great equalizer to outcomes, but also understanding how to personalize the care to subsets of African American men who may have more aggressive disease will be the direction to attempt to eliminate racial disparities in prostate cancer.”
