Genetic testing is increasingly being integrated into the management of men with prostate cancer (PCa) as part of a larger move to personalized medicine.
Clinicians routinely use commercially available genetic assays to identify inherited (germline) mutations that may place men at higher risk for PCa death. Regarding diagnostic risks, genetic assays can help clinicians distinguish men predisposed to aggressive disease from those who likely will have an indolent course so they can adjust screening accordingly. When therapy is needed, results of genetic tests also help guide the use of targeted therapies for men with advanced PCa. For example, identifying certain DNA-repair gene alterations is a prerequisite to the use of PARP inhibitors in men with metastatic castration-resistant prostate cancer (mCRPC).
Recognition of the importance of genetic testing in PCa risk assessment and management has been underscored by the release of 2 new guidelines. One guideline emerged from the 2019 Philadelphia Prostate Cancer Consensus Conference hosted by the Sidney Kimmel Cancer Center at Thomas Jefferson University in Philadelphia. The guideline strongly recommends that the BRCA2 gene be included in all testing scenarios to inform precision therapy in metastatic prostate cancer and to inform active surveillance discussions in early-stage disease and PCa early detection strategies. For men with non-metastatic PCa, the guideline recommends that germline testing be considered for men with Ashkenazi Jewish ancestry, advanced disease (T3a or higher), intraductal or ductal pathology, or Grade Group 4 disease (Gleason sum 8) or higher. Germline testing is recommended for men with 1 brother or father or 2 or more male relatives diagnosed with PCa when they were younger than 60 years, died from PCa, or had metastatic PCa.
The other guideline, which was developed jointly by the American Urological Association, American Society for Radiation Oncology, and Society of Urologic Oncology, contains recommendations for managing advanced PCa that include the use of genetic testing. The guideline recommends that all men with metastatic PCa be offered genetic counseling and germline testing regardless of age and family history. For men with mCRPC, clinicians should offer germline testing and somatic tumor genetic testing “to identify DNA repair deficiency mutations and microsatellite instability status that may inform prognosis and counseling regarding family risk as well as potential targeted therapies.”
Use of PCa genetic testing to stratify risk and guide screening and management continues to gain momentum. Its inclusion into guidelines with specific recommendations could accelerate its integration into PCa care, offering the promise of more nuanced management and better outcomes.