Study finds racial disparity in the utilization of crucial prostate cancer therapy

University of California - Los Angeles Health SciencesDec 1 2023

A new study led by investigators at the UCLA Health Jonsson Comprehensive Cancer Center found Black men diagnosed with more advanced stages of prostate cancer are significantly less likely to be prescribed novel hormone therapy than other racial and ethnic groups – including white or Latino men – despite the therapy being proven to effectively control the growth of prostate tumors and extend the lives of men with the disease.

The findings, published in JAMA Network Open, reveal a concerning racial disparity in the utilization of the crucial therapy for the treatment of the disease.

This revelation is particularly concerning given the already disproportionate impact of prostate cancer on Black men, who are 1.5 times more likely to be diagnosed and 2.4 times more likely to die from the disease than white men in the United States."

Dr. Amar Kishan, co-senior study author, professor of radiation oncology at the David Geffen School of Medicine at UCLA and researcher at the UCLA Health Jonsson Comprehensive Cancer Center

Novel hormonal therapy agents are the next generation of hormonal therapy that targets the androgen signaling axis, which plays a crucial role in the growth and progression of prostate cancer cells. Androgens, such as testosterone, stimulate the growth of prostate cancer. The hormonal therapy works by inhibiting the action of androgens or reducing their levels in the body.

They are also often used in combination with traditional androgen deprivation therapy to more effectively suppress androgen signaling, providing improved outcomes for patients with advanced or metastatic prostate cancer.

"Even though we know hormonal therapies have significant clinical benefits in men with more advanced stages of prostate cancer, there is not much information available about how often people in the general population use these drugs – particularly in the context of equitable access to these medications across different race and ethnicity groups," said Dr. Michael Xiang, assistant clinical professor in radiation oncology at the David Geffen School of Medicine at UCLA and co-senior author of the study.

To look into how doctors prescribe these drugs based on the race and ethnicity of patients in the U.S., the team of researchers used data from a population-based cancer registry linked to prescription drug records for 3,748 Medicare beneficiaries with a median age of 75 with a diagnosis of advanced prostate cancer from 2011 to 2017. Among them, 8% were Black, 7% Hispanic, 78% white, and 7% from other racial and ethnic groups.

The majority of patients had metastatic prostate cancer, with 36% receiving novel hormone therapy. White patients had the highest 2-year novel hormone therapy utilization rate at 27%, followed by Hispanic patients at 25% and other racial/ethnic groups at 23%. Black patients had the lowest rate at 20%.

This disparity persisted at five years and beyond, with Black patients consistently receiving this crucial treatment at a lower rate than their white counterparts. The researchers found Black men were 24% less likely to receive or be prescribed one of these novel hormonal therapy agents as compared to white men. By contrast, this disparity was not observed among Latino men or men of other racial and ethnic groups.

"Our findings raise critical questions regarding the reasons behind this inequality, suggesting possible obstacles to healthcare, financial burdens, and unconscious biases within the healthcare system," said Xiang.

Future studies are needed to uncover underlying causes and to systematically address these issues for more equitable care, noted the authors.

The study's first author is Dr. Ting Martin Ma, a former radiation oncology resident at the David Geffen School of Medicine at UCLA and currently an assistant professor of radiation oncology at University of Washington. Other UCLA authors include: Dr. Matthew Rettig, Dr. Luca Valle, Dr. Michael Steinberg and Dr. Isla Garraway.

This study was funded by the Prostate Cancer Foundation, the American Society for Radiation Oncology and the DeSilva, McCarrick, and Bershad families.