Drivers of racial disparities in prostate cancer trial enrollment

PARP-ish: Gaps in Molecular Understanding and Clinical Trials Targeting PARP Exacerbate Racial Disparities in Prostate Cancer

PARP is a nuclear enzyme with a major function in the DNA damage response. PARP inhibitors (PARPi) have been developed for treating tumors harboring homologous recombination repair (HRR) defects that lead to a dependency on PARP. There are currently three PARPi approved for use in advanced prostate cancer (PCa), and several others are in clinical trials for this disease. Recent clinical trial results have reported differential efficacy based on the specific PARPi utilized as well as patient race. There is a racial disparity in PCa, where African American (AA) males are twice as likely to develop and die from the disease compared to European American (EA) males. Despite the disparity, there continues to be a lack of diversity in clinical trial cohorts for PCa. In this review, PARP nuclear functions, inhibition, and clinical relevance are explored through the lens of racial differences. This review will touch on the biological variations that have been explored thus far between AA and EA males with PCa to offer rationale for investigating PARPi response in the context of race at both the basic science and the clinical development levels.

Germline Mutations and Ancestry in Prostate Cancer

PURPOSE OF REVIEW

Prostate cancer is the most frequently diagnosed non-cutaneous malignancy of men in the USA; notably, the incidence is higher among men of African, followed by European and Asian ancestry. Germline mutations and, in particular, mutations in DNA damage repair genes (DDRGs) have been implicated in the pathogenesis of prostate cancer. This review intends to discuss the implication of ancestry on prostate cancer, specifically in regard to lack of diversity in genomic and genetic databases and the ability of providers to properly counsel patients on the significance of cancer genetic results.

RECENT FINDINGS

Ancestral differences in prostate cancer-associated DDRG germline mutations are increasingly recognized. Guidelines for treatment by the National Comprehensive Cancer Network® (NCCN®) support germline testing in certain patients, and a myriad of genetic testing panels for DDRG mutations are now available in clinical practice. However, the consensus among providers on what genes and mutations to include in the genetic tests has evolved from experience from men of European ancestry (EA). Gaps in ancestry-informed clinical practice exist in genetic risk assessment, implementation of screening, counseling, guiding recommendations, treatment, and clinical trial enrollment. The lack of diversity in tumor genomic and genetic databases may hinder ancestry-specific disease-predisposing alterations from being discovered and targeted in prostate cancer and, therefore, impede the ability of providers to accurately counsel patients on the significance of cancer genetic test results.

The costs and inequities of precision medicine for patients with prostate cancer: A call to action

Financial toxicity is a growing problem in the delivery of cancer care and contributes to inequities in outcomes across the cancer care continuum. Racial/ethnic inequities in prostate cancer, the most common cancer diagnosed in men, are well described, and threaten to widen in the era of precision oncology given the numerous structural barriers to accessing novel diagnostic studies and treatments, particularly for Black men. Gaps in insurance coverage and cost sharing are 2 such structural barriers that can perpetuate inequities in screening, diagnostic workup, guideline-concordant treatment, symptom management, survivorship, and access to clinical trials. Mitigating these barriers will be key to achieving equity in prostate cancer care, and will require a multi-pronged approach from policymakers, health systems, and individual providers. This narrative review will describe the current state of financial toxicity in prostate cancer care and its role in perpetuating racial inequities in the era of precision oncology.

Current Status and Future Direction to Address Disparities in Diversity, Equity, and Inclusion in Prostate Cancer Care

PURPOSE OF REVIEW

Disparities in prostate cancer care and outcomes have been well recognized for decades. The purpose of this review is to methodically highlight known racial disparities in the care of prostate cancer patients, and in doing so, recognize potential strategies for overcoming these disparities moving forward.

RECENT FINDINGS

Over the past few years, there has been a growing recognition and push towards addressing disparities in cancer care. This has led to improvements in care delivery trends and a narrowing of racial outcome disparities, but as we highlight in the following review, there is more to be addressed before we can fully close the gap in prostate cancer care delivery. While disparities in prostate cancer care are well recognized in the literature, they are not insurmountable, and progress has been made in identifying areas for improvement and potential strategies for closing the care gap.