Posted April 22, 2020

The Prostate Cancer Research Program (PCRP) has been committed to addressing prostate cancer health disparities since the inception of the program in fiscal year 1997 (FY97), and more recently has placed a spotlight on addressing the healthcare needs of populations disproportionately affected with prostate cancer through its Overarching Challenge to “Reduce lethal prostate cancer in people of African descent, Veterans, and high-risk or underserved populations.” In addition to funding basic research to identify reasons and provide solutions to resolve prostate cancer disparities, the PCRP has also worked to increase diversity in prostate cancer clinical trials through the PCRP-funded Prostate Cancer Clinical Trials Consortium (PCCTC). Jake Vinson, CEO of the PCCTC, noted, “In line with the CDMRP’s hallmark goal of targeting critical gaps in biomedical research, the PCCTC has developed performance metrics for its clinical research sites to ensure underserved and under-represented communities are enrolled in our studies, and we have promoted a number of investigator-initiated trials investigating the underlying biological etiology of outcome disparities. More recently we have partnered with PCCTC investigators spearheading regional advocacy symposiums. This allows us to present our mission and research opportunities to a more diverse, grassroots prostate cancer community.”

Initially funded by the PCRP in FY05 through the Clinical Consortium Award, and with additional funding support from the Prostate Cancer Foundation, the PCCTC is a network of internationally recognized leaders in the prostate cancer field from the nation’s top academic medical centers and employs a team-based approach to accelerate the development of promising drug candidates in early-phase (Phase I and I/II) clinical trials. While the FY16 and FY17 Clinical Consortium Awards supports ten clinical research sites, including a coordinating center at Memorial Sloan Kettering Cancer Center, the PCCTC has leveraged its infrastructure to extend collaboration with more than 55 affiliate clinical research sites globally. As of May 2019, over 8,400 patients have been accrued to 223 PCCTC-led trials, which have resulted in U.S. Food and Drug Administration approval of three therapies at accelerated rates for prostate cancer patients. 

Since 2005, PCCTC investigators have embraced the PCRP’s challenge to increase enrollment of patients from minority and underserved populations (Figure 1), with some sites having accrued as many as 20%-45% of their patients from disproportionately affected populations (DAP). Based on recent numbers reported by the PCCTC clinical research sites, Wayne State University/Barbara Ann Karmanos Cancer Institute (WSU/KCI) in Detroit, Michigan, had an impressive 42% minority (predominantly African American [AA]) accrual rate. They attribute their high DAP enrollment to several factors, including their dedicated teams of clinicians and investigators, as well as investigator-initiated research focused on improving clinical trial accrual among underserved populations. When asked about the success of the site, Dr. Elisabeth Heath, lead Principal Investigator (PI) at WSU/KCI stated, “I’ve learned that it’s important to reach patients where they are. The first step is critical: communicating with the public in language they understand. Our patient advocates play an important role in this. Advocates give us feedback in how to best present research, which provides a tremendous help in recruiting patients for clinical trials.” By offering improved access to the local healthcare system and working to overcome barriers often faced by disparate populations, the site at WSU/KCI has provided greater opportunities for community members to participate in critical clinical prostate cancer trials.

Duke Cancer Institute attributes their 21% DAP accrual rate, in part, to efforts to extend every clinical trial opportunity to AA patients, as well as their team’s interest in conducting research on disparities. Duke is the lead site on two PCCTC trials comparing treatment response in African Americans vs. Caucasian men: Abi Race (A Phase II open-label, parallel group study of Abiraterone Acetate plus Prednisone in African American and Caucasian men with metastatic castrate-resistant prostate cancer; NCT01940276) and PANTHER (Prospective study of Apalutamide and Abiraterone Acetate in Chemotherapy-Naïve men with mCRPC Stratified by Race; NCT03098836). Dr. Daniel George, PI of the Duke Cancer Institute PCCTC site, has shared their landmark efforts in this area in a 2019 talk at the American Society of Clinical Oncology, “More Than Skin Deep: Investigating Disease Biology, Treatment Response, and Side Effect Differences by Race.”

Another PCCTC site representing a remarkable inclusion of under-represented populations in clinical trials is Oregon Health and Science University, reporting a 35% DAP accrual rate. Their enrollment strategy includes extending access to clinical trials to rural populations in the areas surrounding the site, including counties in Washington and Idaho with formal rural designation. “As Oregon’s only academic medical center, the OHSU Knight Cancer Institute has the responsibility of serving all the state’s residents in the areas of cancer education, prevention, and care. A particular strength of our program lies in outreach to rural areas where access to health care is limited: our clinical trials routinely enroll patients from rural areas at numbers in alignment with Oregon demographics, approximately 35% rural dwellers,” Kristi Eilers, Senior Clinical Research Manager at OHSU, said. “To support the accrual of rural Oregonians to clinical trials, we have invested resources [in an] effort to offer travel reimbursement. We have also established successful relationships with laboratories and imaging facilities to enable research procedures to be completed in local communities. Our faculty also visit rural oncology practices to offer educational programs for patients and we regularly update rural oncologists about our clinical trial options.”

In addition to increasing diversity in clinical trials, the PCCTC is collecting comprehensive patient-focused information by establishing the International Registry to Improve Outcomes in Men with Advanced Prostate Cancer, nicknamed “IRONMAN.” They have been actively recruiting a racially and ethnically diverse group, across the globe, of 5,000 men with advanced prostate cancer. Characterizing tumors and outcomes of the patients in this registry will develop a deeper understanding of who and when a patient can benefit from specific treatments, and provide data to inform future studies that address prostate cancer health disparities, ultimately improving care for all prostate cancer patients on a global scale. 

The collective contributions of the PCCTC sites to increase accrual from DAP and develop a comprehensive registry from a diverse patient population are contributing outcomes data that will hopefully shed light on the underlying factors contributing to prostate cancer health disparities. AA men have historically displayed statistically higher diagnostic and mortality rates compared to Caucasian American men of the same age, although the low representation of AA men in clinical trials leaves open the question of whether this disparity is due to differences in disease biology, or access to care and treatment choice. New results from clinical studies (1) where AA men and non-Hispanic white men have access to the same care or treatments are supporting the hypothesis that access to care, and not biological contributors, is the driving factor. But more clinical studies with adequate participant diversity are needed to address these important questions and eventually eliminate health disparities among different populations. These efforts to understand and overcome health disparities is an undertaking the PCCTC is committed to, making it a leader in the field. The strategies employed by the PCCTC could inform other research and healthcare organizations to also join in the mission to expand access for patients, regardless of location, race, or ethnicity, and ultimately help address the PCRP’s goal of resolving prostate cancer health disparities and ultimately conquering prostate cancer for all men. 

Figure 1. The PCRP and PCCTC have prioritized the inclusion of under-represented and understudied populations in clinical research to narrow the gap in health disparities among prostate cancer patients. Displayed are the total number of patients accrued to PCCTC trials between 2018 and 2019 at each of the ten funded clinical research sites as well as the percentage of patients each site accrued from disproportionately affected populations (DAP).

References:

(1) Riviere P, Luterstein E, Kumar A, Vitzthum LK, Deka R, Sarkar RR, Bryant AK, Bruggeman A, Einck JP, Murphy JD, Martinez E, Rose BS. 2020. Survival of African American and non-Hispanic white men with prostate cancer in equal-access health care system. Cancer 126(8):1683-1690.

(2) Dess RT, Hartman HE, Mahal BA, et al. 2019. Association of black race with prostate cancer–specific and other-cause mortality. JAMA Oncol 5(7):975-983. 

Links:

Public and Technical Abstracts from the PCCTC Awards:

PCCTC: Coordinating Center with Clinical Research Site Option – Memorial Sloan Kettering Cancer Center

PCCTC: Clinical Research Site – Wayne State University

PCCTC: Clinical Research Site – Duke University

PCCTC: Clinical Research Site – Oregon Health and Science University

PCCTC: Clinical Research Site – Joan and Sanford I Weill Medical College of Cornell University

PCCTC: Clinical Research Site – University of California, San Francisco

PCCTC: Clinical Research Site – University of Wisconsin Carbone Cancer Center

PCCTC: Clinical Research Site – Dana-Farber Cancer Institute

PCCTC: Clinical Research Site – Johns Hopkins Kimmel Cancer Center

PCCTC: Clinical Research Site – University of Washington

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