1. Pilot Study: PARP1 Imaging in Advanced Prostate Cancer
- Author
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Farrokh Dehdashti, Melissa A. Reimers, Kooresh I. Shoghi, Delphine L. Chen, Jingqin Luo, Buck Rogers, Russell K. Pachynski, Sreeja Sreekumar, Cody Weimholt, and Dong Zhou
- Subjects
Male ,Cancer Research ,Oncology ,Positron Emission Tomography Computed Tomography ,Poly (ADP-Ribose) Polymerase-1 ,Humans ,Prostatic Neoplasms ,Radiology, Nuclear Medicine and imaging ,Pilot Projects ,Antineoplastic Agents ,Poly(ADP-ribose) Polymerase Inhibitors - Abstract
Purpose PARP inhibitor (PARPi) therapy is approved for patients with metastatic castration-resistant prostate cancer (mCRPC) and homologous recombination repair (HRR) genomic aberrations. However, only a fraction of patients with BRCA1/2 mutations respond to PARPi therapy. In this pilot study, we assess PARP-1 expression in prostate cancer patients with and without HRR genomic alternations using a novel PARP-based imaging agent. Procedures Nine advanced prostate cancer patients were studied with PET/CT and [18F]FluorThanatrace (FTT), an analogue of the PARPi rucaparib. Images were analyzed using maximum standardized uptake values (SUVmax). PARP expression was assessed by immunohistochemistry (IHC) when feasible (n = 4). Results We found great variability in FTT uptake (SUVmax range: 2.3–15.4). Patients with HRR mutations had a significantly higher SUVmax (p = 0.0379) than patients with non-HRR mutations although there was an overlap in FTT uptake between groups. Three patients without HRR and one with HRR mutations had similarly high PARP1 IHC expression. Conclusions FTT-PET/CT may serve as an alternate biomarker for PARP1 expression and a potential method for PARPi treatment selection.
- Published
- 2022