Disparities in precision medicine-Examining germline genetic counseling and testing patterns among men with prostate cancer

Expert Perspectives on Controversies in Metastatic Castration-Resistant Prostate Cancer Management: Narrative Review and Report of the First US Prostate Cancer Conference Part 2

Background

Management strategies for metastatic castration-resistant prostate cancer (mCRPC) have rapidly shifted in recent years. As novel imaging and therapeutic approaches have made their way to the clinic, providers are encountering increasingly challenging clinical scenarios, with limited guidance from the current literature.

Materials and Methods

The US Prostate Cancer Conference (USPCC) is a multidisciplinary meeting of prostate cancer experts intended to address the many challenges of prostate cancer management. At the first annual USPCC meeting, areas of controversy and consensus were identified during a 2-day meeting that included expert presentations, full-panel discussions, and postdiscussion responses to questions developed by the USPCC cochairs and session moderators.

Results

This narrative review covers the USPCC expert discussion and perspectives relevant to mCRPC, including neuroendocrine/aggressive-variant prostate cancer (NEPC/AVPC). Areas of broad agreement identified among USPCC experts include the benefits of poly (ADP-ribose) polymerase (PARP) inhibitors for patients with BRCA1/2 mutations, the use of radioligand therapy in patients with prostate-specific membrane antigen (PSMA)-positive mCRPC, and the need for clinical trials that address real-world clinical questions, including the performance of novel therapies when compared with modern standard-of-care treatment. Ongoing areas of controversy and uncertainty included the appropriateness of PARP inhibitors in patients with non-BRCA1/2 mutations, the optimal definition of PSMA positivity, and systemic therapies for patients with NEPC/AVPC after progression on platinum-based therapies.

Conclusions

The first annual USPCC meeting identified several areas of controversy in the management of mCRPC, highlighting the urgent need for clinical trials designed to facilitate treatment selection and sequencing in this heterogeneous disease state.

Addressing disparities in cancer clinical trials: a roadmap to more equitable accrual

The Georgia Center for Oncology Research and Education (Georgia CORE) and the Georgia Society of Clinical Oncology (GASCO) held a one-day summit exploring opportunities and evidence-based interventions to address disparities in cancer clinical trials. The purpose of the summit was to identify clear and concise recommendations aimed at decreasing clinical trial accrual disparities in Georgia for rural and minority populations. The summit included expert presentations, panel discussions with leaders from provider organizations throughout Georgia, and breakout sessions to allow participants to critically discuss the information presented. Over 120 participants attended the summit. Recognizing the need for evidence-based interventions to improve clinical trial accrual among rural Georgians and persons of color, summit participants identified four key areas of focus that included: improving clinical trial design, providing navigation for all, enhancing public education and awareness of cancer clinical trials, and identifying potential policy and other opportunities. A comprehensive list of takeaways and action plans was developed in the four key areas of focus with the expectation that implementation of the strategies that emerged from the summit will enhance cancer clinical trial accrual for all Georgians.

Characterizing Referrals for Prostate Cancer Genetic Services in a Safety-Net Hospital

PURPOSE

Little is known about the uptake of germline genetic testing for patients with prostate cancer after 2018 guideline changes. This study characterizes genetic service referral patterns and predictors of referrals among patients with prostate cancer.

METHODS

A retrospective cohort study using electronic health record data was conducted at an urban safety-net hospital. Individuals diagnosed with prostate cancer between January 2011 and March 2020 were eligible. The primary outcome was referral to genetic services after diagnosis. Using multivariable logistic regression, we identified patient characteristics associated with referrals. Interrupted time series analysis using a segmented Poisson regression examined whether guideline changes resulted in higher rates of referral after implementation.

RESULTS

The cohort included 1,877 patients. Mean age was 65 years; 44% identified as Black, 32% White; and 17% Hispanic or Latino. The predominant insurance type was Medicaid (34%) followed by Medicare or private insurance (25% each). Most were diagnosed with local disease (65%), while 3% had regional and 9% had metastatic disease. Of the 1,877 patients, 163 (9%) had at least one referral to genetics. In multivariable models, higher age was negatively associated with referral (odds ratio [OR], 0.96; 95% CI, 0.94 to 0.98), while having regional (OR, 4.51; 95% CI, 2.44 to 8.34) or metastatic disease (OR, 4.64; 95% CI, 2.98 to 7.24) versus local only disease at diagnosis was significantly associated with referral. The time series analysis demonstrated a 138% rise in referrals 1 year after guideline implementation (relative risk, 3.992; 97.5% CI, 2.20 to 7.24; P < .001).

CONCLUSION

Referrals to genetic services increased after guideline implementation. The strongest predictor of referral was clinical stage, suggesting opportunities to raise awareness about guideline eligibility for patients with advanced local or regional disease who may benefit from genetic services.

Racial Differences in Germline Genetic Testing for Prostate Cancer: A Systematic Review

PURPOSE

Testing for pathogenic variants can aid in oncologic risk stratification and identification of targeted therapies. Despite known disparities in access to prostate cancer (PCa) care, little has been written about access to germline genetic testing (GGT) for Black men and other historically marginalized populations. This systematic review sought to delineate racial/ethnic disparities in GGT for PCa.

METHODS

This systematic review identified articles published from January 1996 through May 2021 in PubMed, Web of Science, and Embase. We included studies that reported rates of GGT in men with PCa in the United States by race/ethnicity as reflective of routine clinical care or research. A narrative synthesis was performed.

RESULTS

Of 4,309 unique records, 91 studies examining 50 unique study populations met inclusion criteria. Of these, four populations included men who received GGT through routine clinical care, accounting for 4,415 men (72.6% White and 7.2% Black). The other 46 populations included men who received GGT as part of a research study, accounting for 30,824 men (64.3% White and 21.6% Black). Of these 46 research populations, 19 used targeted methods to increase recruitment from a specific demographic.

CONCLUSION

Most studies that report GGT rates by race/ethnicity are in research settings. Many of these studies used targeted recruitment methods and subsequently have a greater proportion of Black men than clinical and US population-based studies. Other historically marginalized populations are not well represented. There remains a knowledge gap regarding the extent of racial disparities in the use of GGT, particularly in the clinical setting.

Implementation of a Telehealth Genetic Testing Station to Deliver Germline Testing for Men With Prostate Cancer

PURPOSE

Germline testing for men with prostate cancer (PCa) poses numerous implementation barriers. Alternative models of care delivery are emerging, but implementation outcomes are understudied. We evaluated implementation outcomes of a hybrid oncologist- and genetic counselor-delivered model called the genetic testing station (GTS) created to streamline testing and increase access.

METHODS

A prospective, single-institution, cohort study of men with PCa referred to the GTS from October 14, 2019, to October 14, 2021, was conducted. Using the Reach, Effectiveness, Adoption, Implementation, and Maintenance framework, we described patients referred to GTS (Reach), the association of GTS with germline testing completion rates within 60 days of a new oncology appointment in a pre- versus post-GTS multivariable logistic regression (Effectiveness), Adoption, Implementation, and Maintenance. Because GTS transitioned from an on-site to remote service during the COVID-19 pandemic, we also compared outcomes for embedded versus remote GTS.

RESULTS

Overall, 713 patients were referred to and eligible for GTS, and 592 (83%) patients completed germline testing. Seventy-six (13%) patients had ≥ 1 pathogenic variant. Post-GTS was independently associated with higher odds of completing testing within 60 days than pre-GTS (odds ratio, 8.97; 95% CI, 2.71 to 29.75; P < .001). Black race was independently associated with lower odds of testing completion compared with White race (odds ratio, 0.35; 95% CI, 0.13 to 0.96; P = .042). There was no difference in test completion rates or patient-reported decisional conflict for embedded versus remote GTS. GTS has been adopted by 31 oncology providers across four clinics, and implementation fidelity was high with low patient loss to follow-up, but staffing costs are a sustainability concern.

CONCLUSION

GTS is a feasible, effective model for high-volume germline testing in men with PCa, both in person and using telehealth. GTS does not eliminate racial disparities in germline testing access.

Disparities in cancer genetics care by race/ethnicity among pan-cancer patients with pathogenic germline variants

BACKGROUND

Germline risk assessment is increasing as part of cancer care; however, disparities in subsequent genetic counseling are unknown.

METHODS

Pan-cancer patients were prospectively consented to tumor-normal sequencing via custom next generation sequencing panel (Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets) inclusive of germline analysis of ≥76 genes from January 2015 through December 2019 (97.5% research nonbillable) with protocol for genetics referral. Rates of pathogenic/likely pathogenic germline variants (PVs) and downstream counseling were compared across ancestry groups (mutually exclusive groups based on self-reported race/ethnicity and Ashkenazi Jewish [AJ] heritage) using nonparametric tests and multivariable logistic regression models.

RESULTS

Among 15,775 patients (59.6%, non-Hispanic [NH]-White; 15.7%, AJ; 20.5%, non-White [6.9%, Asian; 6.8%, Black/African American (AA); 6.7%, Hispanic; 0.1%, Other], and 4.2%, unknown), 2663 (17%) had a PV. Non-White patients had a lower PV rate (n = 433, 13.4%) compared to NH-Whites (n = 1451, 15.4%) and AJ patients (n = 683, 27.6%), p < .01, with differences in mostly moderate and low/recessive/uncertain penetrance variants. Among 2239 patients with new PV, 1652 (73.8%) completed recommended genetic counseling. Non-White patients had lower rates of genetic counseling (67.7%) than NH-White (73.7%) and AJ patients (78.8%), p < .01, with lower rates occurring in Black/AA (63%) compared to NH-White patients, even after adjustment for confounders (odds ratio, 0.60; 95% confidence interval, 0.37-0.97; p = .036). Non-White, particularly Black/AA and Asian, probands had a trend toward lower rates and numbers of at-risk family members being seen for counseling/genetic testing.

CONCLUSIONS

Despite minimizing barriers to genetic testing, non-White patients were less likely to receive recommended cancer genetics follow-up, with potential implications for oncologic care, cancer risk reduction, and at-risk family members.

LAY SUMMARY

Genetic testing is becoming an important part of cancer care, and we wanted to see if genetics care was different between individuals of different backgrounds. We studied 15,775 diverse patients with cancer who had genetic testing using a test called MSK-IMPACT that was covered by research funding. Clinically important genetic findings were high in all groups. However, Black patients were less likely to get recommended counseling compared to White patients. Even after removing many roadblocks, non-White and especially Black patients were less likely to get recommended genetics care, which may affect their cancer treatments and families.

A Community-Engaged Process for Adapting a Proven Community Health Worker Model to Integrate Precision Cancer Care Delivery for Low-income Latinx Adults With Cancer

INTRODUCTION

Disparities in precision cancer care delivery among low-income Latinx adults are well described. In prior work, we developed a community health worker-led goals of care and cancer symptom assessment intervention. The objective of this study was to adapt this intervention for a community setting, incorporating precision cancer care delivery.

METHODS

We used a two-phased systematic approach to adapt an evidence-based intervention for our community. Specifically, we used the Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) framework to identify barriers and facilitators to precision cancer care delivery via 1-hr interviews with Latinx adults with cancer, Latinx caregivers, community leaders, primary care and oncology clinicians, and community health workers. Interviews were recorded, transcribed, and analyzed using the constant comparative method and grounded theory analysis. Phase 2 involved interviews with key community advisors using the Expert Panels Method to decide on final adaptations.

RESULTS

Using this community-engaged approach, we identified specific intervention adaptations to ensure precision cancer care delivery in a community setting, which included: (a) expansion of the intervention inclusion criteria and mode of delivery; (b) integration of low-literacy precision cancer care intervention activities in Spanish in collaboration with community-based organizations; (c) ensuring goals reflective of patient and community priorities.

CONCLUSIONS

This systematic and community-engaged approach to adapt an intervention for use in delivering precision cancer care strengthened an evidence-based approach to promote the needs and preferences of patients and key community stakeholders.

Disparities in Genetic Testing for Heritable Solid-Tumor Malignancies

Genetic testing offers providers a potentially life saving tool for identifying and intervening in high-risk individuals. However, disparities in receipt of genetic testing have been consistently demonstrated and undoubtedly have significant implications for the populations not receiving the standard of care. If correctly used, there is the potential for genetic testing to play a role in decreasing health disparities among individuals of different races and ethnicities. However, if genetic testing continues to revolutionize cancer care while being disproportionately distributed, it also has the potential to widen the existing mortality gap between various racial and ethnic populations.

Disparities in germline testing among racial minorities with prostate cancer

Germline testing is becoming increasingly relevant in prostate cancer (PCa) screening, prognosis, and management. A subset of patients with PCa harbor pathogenic/likely pathogenic variants (P/LPVs) in genes mediating DNA-repair processes, and these P/LPVs have implications for cancer screening, treatment, and cascade testing. As a result, it is recommended that all men with high-risk localized and metastatic PCa undergo routine germline testing. As more PCa patients undergo germline testing, it is important that clinicians and genetics experts recognize current disparities in germline testing rates among racial/ethnic minorities in the United States. The reasons for these disparities are multiple and require similarly manifold consideration to close the germline testing gap and reduce inequities in PCa screening, management, and treatment.

Adopting Consensus Terms for Testing in Precision Medicine

Despite the well-understood benefits of biomarker and genetic testing in precision medicine, uptake remains low, particularly for patients with low socioeconomic status and minority ethnic backgrounds. Patients report having limited familiarity with testing terminology and may not be able to accurately explain testing's role in treatment decisions. Patient confusion and lack of understanding is exacerbated by a multiplicity of overlapping terms used in communicating about testing. A LUNGevity Foundation–led working group composed of five professional societies, 23 patient advocacy groups, and 19 industry members assessed and recommended specific terms for communicating with patients on testing for tumor characteristics and germline mutations.