In addition to germline, somatic genomic testing is the standard of care in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC). Although initial testing with tissue is recommended by current guidelines, there is a lack of consensus about the type of tissue to use and how to integrate circulating tumor DNA (ctDNA) into the overall strategy for somatic testing. In this community-based descriptive feasibility analysis study, simultaneous genomic testing with germline, tissue, and initial ctDNA was done as well as repeat ctDNA with tumor progression to maximize detection of an actionable alteration with an FDA-approved drug.
All patients had germline, initial ctDNA, and tissue testing when available. Selected pts had repeat ctDNA testing with tumor progression. The availability of quality tumor tissue, the frequency of detection of actionable variants, the source of genomic material, and the prostate-specific antigen (PSA) response to genomic-directed treatment are reported.
A total of 150 pts were enrolled. All had germline and initial ctDNA testing. Results from tissue testing were available in 72 pts. Tumor tissue was not available or had insufficient DNA for sequencing in the other pts. Repeat ctDNA was done in 40 pts. Overall, 67 (45%) pts had an alteration with an FDA-approved drug. Testing with initial ctDNA identified 27%, tissue in 8%, and repeat ctDNA in 10% of pts. To date, 35 pts have received treatment. The PSA50 was 32%.
In this descriptive feasibility analysis study conducted in a community-based setting, comprehensive genomic testing resulted in the identification of a large number of pts with an actionable alteration for treatment with an FDA-approved drug. Sequencing results from tissue were available in only half of pts, highlighting the challenges of obtaining tumor tissue for genomic testing. Repeat ctDNA testing at progression performed in selected pts resulted in the detection of an actionable alteration in additional pts.
Clinical genitourinary cancer. 2026 Apr 27 [Epub ahead of print]
Daniel Shevrin, Mathew Yang, Linda M Sabatini, Michael Akroush, Nicklas Pfanzelter, Hussein Alnajar, Henry Wittich, Donald L Helseth
Division of Hematology and Oncology, Department of Medicine, Endeavor Health, Evanston, IL. Electronic address: ., Mark R. Neaman Center for Personalized Medicine, Endeavor Health, Evanston, IL., Department of Pathology, Endeavor Health, Evanston, IL., Division of Hematology and Oncology, Department of Medicine, Endeavor Health, Evanston, IL.