While some studies have determined that it is safe to delay treatment and monitor some slow-growing or low-risk prostate cancers, these findings show that this approach -- called active surveillance -- is not a good idea for black men, the Johns Hopkins researchers concluded.
"This study offers the most conclusive evidence to date that broad application of active surveillance recommendations may not be suitable for African- Americans," study co-author and urologist Dr. Edward Schaeffer said in a Hopkins news release.
"This is critical information because if African- American men do have more aggressive cancers, as statistics would suggest, then simply monitoring even small cancers that are very low-risk would not be a good idea because aggressive cancers are less likely to be cured," he explained.
"We think we are following a small, nonaggressive cancer, but in reality this study highlights that in black men, these tumors are sometimes more aggressive than previously thought. It turns out that black men have a much higher chance of having a more aggressive tumor developing in a location that is not easily sampled by a standard prostate biopsy."
The study included 1,473 white men and 256 black men who were diagnosed with very-low-risk prostate cancer and thus believed to be good candidates for active surveillance. The findings were published online recently ahead of print in the Journal of Clinical Oncology.
"In the laboratory, we are developing new strategies to more accurately risk-classify African- Americans with newly diagnosed prostate cancer, in order to determine whether a patient should undergo active surveillance or have immediate treatment," Schaeffer said in the news release.
"And we are beginning to work out the science behind why prostate cancers have a tendency to hide out in the anterior prostate, specifically in African- Americans," he added.
Although the reasons are unclear, U.S. National Cancer Institute statistics from 2005 to 2009 show that prostate cancer rates are much higher among black men (236 cases per 100,000) than among white men (146.9 cases per 100,000).
The U.S. National Cancer Institute has more about prostate cancer.