Focal therapy is an emerging treatment for localized prostate cancer, but there is a paucity of data on its use in diverse racial populations. In 2016, the National Institutes of Health published the Final Rule, which required the reporting of race in clinical trials if collected under the study protocol.¹ Our objective was to evaluate racial diversity in clinical trials investigating focal therapy for prostate cancer after January 2017, the effective date of the Final Rule.

We queried PubMed and clinicaltrials.gov in January of 2023 using the terms “prostate cancer” and “focal therapy” to identify all published and completed clinical trials on focal therapy for prostate cancer between 2017 and 2023. We extracted study characteristics and analyzed those that reported race. Trials were excluded if focal therapy was used in combination with other treatments or as salvage therapy.

Out of the 792 studies found on PubMed and 288 studies found on clinicaltrials.gov, 71 clinical trials and 1,005 subjects met our inclusion criteria. High-intensity focused ultrasound (n=22, 31.0%), brachytherapy (n=13, 18.6%), irreversible electroporation (n=9, 12.7%), and cryotherapy (n=9, 12.7%) were the most studied modalities. However, only 11 out of 71 (15.5%) clinical trials provided information regarding race or ethnicity. Of these, 92.8% (n=933) of individuals were White, 3.1% (n=31) were Black, 1.7% (n=17) were multiracial, and 0.6% (n=6) were Asian.

Our study highlights the lack of racial reporting and underrepresentation of minorities in clinical trials investigating prostate cancer focal therapy. Race was not reported in almost 85% of clinical trials, and Black men constituted about 3% of study participants, despite accounting for 35% of prostate cancer diagnoses in the United States.² Similarly, Asian men represented 0.6% of subjects in clinical trials, but account for 11% of prostate cancer diagnoses nationally.² Over 90% of individuals were White, though White men constitute only 21% of prostate cancer diagnoses (see Figure).²

Figure. Comparison of the racial burden of prostate cancer diagnoses and representation in focal therapy clinical trials.

There is a long history of underrepresentation of minorities in clinical trials. In 1993, the National Institutes of Health Revitalization Act established policies for inclusion of women and minorities in clinical research.³ However, a study in 2014 reported that less than 2% of National Cancer Institute trials included minority populations.⁴ The Final Rule, effective in January 2017, is meant to rectify this disparity and requires the reporting of race if it was collected under the study protocol.¹

However, with over 80% of focal therapy clinical trials failing to report race, underrepresentation of minorities in clinical trials remains a significant issue. It is critical that clinical trial populations reflect the racial distribution of the disease being studied so that results are generalizable to these demographics. Many mechanisms have been described to help achieve this goal including partnering with community hospitals, engagement within the community to build trust, anticipating cultural barriers to research, and including diverse medical professionals throughout the research process and on medical journal editorial boards.⁵ Finally, we recommend an addendum to the Final Rule, namely that it be mandatory to report race in clinical trials. This will increase transparency and promote proportionate representation of minorities.

Conflicts of Interest

The Authors have no conflicts of interest to disclose.