Black men who received radiation therapy for localized prostate cancer fared better.
Overall, Black men have a 50% higher risk of being diagnosed with prostate cancer, and an 80% greater risk of death than White men. Those numbers have complicated roots: There are differences in access to medical care, clinical trial enrollment, access to screening, and frequency of definitive treatment.
The new study, published online Dec. 29, 2021, in JAMA Network Open, was a meta-analysis of 8,814 men (18.5% Black, 81.5% White) who participated in 7 randomized, clinical trials that compared definitive radiotherapy with or without short- or long-term androgen deprivation therapy. The researchers found that Black men had more features of high-risk disease, but they were less likely than White men to experience biochemical recurrence (subdistribution hazard ratio, 0.79; P < .001), distant metastasis (sHR, 0.69; P = .002), or prostate cancer-specific mortality (sHR, 0.68; P = .01).
“These results provide high-level evidence challenging the common belief that Black men who are diagnosed with prostate cancer will necessarily have a worse prognosis than White men,” said study coauthor Amar Kishan, MD, in a press release. Dr. Kishan is associate professor and vice chair of clinical and translational research at the University of California, Los Angeles, and a researcher at the UCLA Jonsson Comprehensive Cancer Center.
“This is especially important because an unfounded belief can inadvertently contribute to ‘cancer injustice,’ leading to the use of more aggressive treatments than might be necessary – potentially reducing quality of life and diverting attention away from other important factors that can influence outcome, including access to more comprehensive health care,” Dr. Kishan said.
Better health care coverage may indeed be the driving force behind the benefit, according to an accompanying editorial authored by Bogdana Schmidt, MD, MPH and Neeraj Agarwal, MD, of the Huntsman Cancer Institute at the University of Utah, Salt Lake City. The results suggest that, when Black men with prostate cancer get the high quality of care seen in clinical trials and receive definitive therapy, they achieve good results.
It also suggests a path toward improving outcomes. “Through a multidisciplinary effort of enriching cohort studies with Black men, enrolling Black men into clinical trials and continuing the search for tumor-specific genomic factors, treatment-specific response factors, and pharmacologic response differences, as a community we can unequivocally improve prostate cancer care for Black men,” the editorial authors wrote.
Enrollment in clinical trials has also been linked to improved outcomes in studies of docetaxel and prednisone, enzalutamide and androgen deprivation therapy, and abiraterone acetate and prednisone. Other studies have shown that Black men in clinical trials or who get treated in high-volume centers are less likely to experience the adverse outcomes seen more widely among Black men.
The new finding that Black men have better outcomes with radiotherapy may also have a biological basis, as a retrospective study of patients undergoing prostatectomy for prostate cancer found that Black men had lower levels of mismatch repair genes and DNA repair activity.
The study isn’t the first to implicate access to care in outcome differential between Black and White men with prostate cancer. A 2019 study compared outcomes between White and Black men within registries that have standardized access, which is expected to minimize racial disparities. The researchers found no differences in prostate cancer–specific mortality within these databases. However, the differences in outcomes surfaced between Black and White men when they examined data from a large federal registry that reflects social and economic barriers to health care.
The authors of both the study and the editorial have extensive financial relationships with pharmaceutical companies.