The study suggests new avenues for treating black patients who die disproportionately from prostate cancer
A study involving equal numbers of black and white men with advanced prostate cancer confirms key findings revealed in retrospective analyzes and suggests possible new avenues for treating black patients who die disproportionately from the disease.
Researchers at the Duke Cancer Institute included 50 black and 50 white men with advanced prostate cancer to test whether there were any differences in results when treated with the hormone therapy abiraterone acetate plus the steroid prednisone. In retrospective data reviews, the Duke researchers had previously found racial differences in PSA responses in patients with advanced prostate cancer.
The researchers, published online in the journal Cancer, confirmed trends indicating that PSA levels in black men fell further and more frequently than those of white men undergoing therapy. However, these PSA changes did not lead to differences in disease progression or overall survival times.
But the survival finding has an important subtlety, said senior author Daniel George, MD, a professor in the departments of medicine and surgery at Duke University School of Medicine. George noted that most drug studies in prostate cancer patients involve a small proportion of black men, well below their number in the larger population.
Exclusions usually come because black men with prostate cancer are more likely to have other diseases, such as diabetes and high blood pressure, which study leaders often fear put at a higher risk of complications. In addition, there are deep historical and cultural reasons why black men tend to refuse to take part in clinical trials.
For their study, the Duke team – including lead author Andrew Armstrong, MD, professor in the departments of medicine and surgery – found that black men were willing to take part in the clinical trial.
They were able to enroll a much larger proportion of black men than most studies, partly because the study was about a race-related issue. And they didn’t exclude men with co-existing conditions, claiming that they should include the patients they see in the office, as the treatment is FDA cleared for this population.
“If you look at the overall survival data for our study, they are the same between black and white men,” said George. “Given the incidence of co-existing illnesses among the black men we enroll, the mortality rate for them should actually have been higher.
Our finding that it was no higher is telling – it suggests that black men with prostate cancer can do as well as whites on other health issues as well. And it signals that future studies should consider enrolling black men despite these often disqualifying conditions. “
Daniel George, MD, Principal Investigator and Professor, Departments, Medicine and Surgery, Duke University School of Medicine
George said the researchers had also identified a potential marker of ancestry-dependent treatment outcomes that could explain why black men respond more easily to hormone therapy and potentially reveal new ways to address advanced prostate cancer in black men.
‘We need to understand how genetic ancestry can affect outcomes – especially prostate cancer disease response – as we now apply and study these therapies earlier on the disease where we have the ability to cure patients,’ said George.
“If there is a subset of patients with an ancestral predisposition for potentially better response, we need to understand. But to do that we need greater genetic diversity in our future study populations, especially in patients of African descent. We will be genetic Not fully understanding complexity when I only enroll men of European descent. “
Duke University Medical Center
George, DJ et al. (2021) A prospective study of abiraterone acetate plus prednisone in black-and-white men with metastatic castrate-resistant prostate cancer. Cancer. doi.org/10.1002/cncr.33589.