Systemic androgen-signaling inhibition added to ongoing androgen-deprivation therapy (ADT) improved clinical outcomes in patients with nonmetastatic castration-resistant prostate cancer without detectable metastases by conventional imaging (nmCRPC). Prostate-specific membrane antigen ligand positron-emission tomography (PSMA-PET) detects prostate cancer with superior sensitivity to conventional imaging, but its performance in nmCRPC remains largely unknown. We characterized cancer burden in high-risk nmCRPC patients using PSMA-PET.
We retrospectively included 200 patients with nmCRPC, prostate-specific antigen (PSA) >2 ng/mL, and high risk for metastatic disease (PSA doubling time [PSADT] ≤10 months and/or Gleason score ≥8) from six high-volume PET centers. We centrally reviewed PSMA-PET detection rate for pelvic disease and distant metastases (M1). We further evaluated SPARTAN patients stratified by risk factors for PSMA-PET-detected M1 disease.
PSMA-PET was positive in 196/200 patients. Overall, 44% had pelvic disease including 24% with local prostate bed recurrence, and 55% had M1 disease despite negative conventional imaging. Interobserver agreement was very high (κ 0.81-0.91). PSA ≥5.5 ng/mL, loco-regional nodal involvement determined by pathology (pN1), prior primary radiation, and prior salvage radiation therapy independently predicted M1 disease (all P < 0.05).
PSMA-PET detected any disease in nearly all patients and M1 disease in 55% of patients previously diagnosed with nmCRPC, including subgroups with PSADT ≤10 months and Gleason score ≥8. The value of PSMA-PET imaging for treatment guidance should be tested in future studies.
Clinical cancer research : an official journal of the American Association for Cancer Research. 2019 Sep 11 [Epub ahead of print]
Wolfgang P Fendler, Manuel Weber, Amir Iravani, Michael S Hofman, Jérémie Calais, Johannes Czernin, Harun Ilhan, Fred Saad, Eric J Small, Matthew R Smith, Paola M Perez, Thomas A Hope, Isabel Rauscher, Anil Londhe, Angela Lopez-Gitlitz, Shinta Cheng, Tobias Maurer, Ken Herrmann, Matthias Eiber, Boris Hadaschik
Department of Nuclear Medicine, University of Duisburg-Essen and German Cancer Consortium (DKTK)-University Hospital Essen ., University of Duisburg-Essen and German Cancer Consortium (DKTK)-University Hospital Essen., Cancer Imaging, Peter MacCallum Cancer Centre., Cancer Imaging, Peter MacCallum Cancer Service., University of California Los Angeles., Department of Molecular and Medical Pharmacology, University of California Los Angeles., Department of Nuclear Medicine, Ludwig-Maximilians-University., CRCHUM, Centre Hospitalier de l’Université de Montréal, Université de Montréal., Medical Oncology, Helen Diller Family Comprehensive Cancer Center, University of California San Francisco., Hematology-Oncology, Massachusetts General Hospital Cancer Center and Harvard Medical School., Helen Diller Family Comprehensive Cancer Center, University of California San Francisco., Department of Radiology and Biomedical Imaging, University of California, San Francisco., Department of Nuclear Medicine, Klinikum Rechts der Isar, Technical University of Munich., Janssen Research & Development., Research & Development, Janssen (United States)., Oncology, Janssen Research & Development., Department of Urology, University Medical Center Hamburg-Eppendorf., Department of Nuclear Medicine, University of Duisburg-Essen and German Cancer Consortium (DKTK)-University Hospital Essen., Nuclear Medicine, Klinikum Rechts der Isar, Technical University Munich., Department of Urology, University of Duisburg-Essen and German Cancer Consortium (DKTK)-University Hospital Essen.