Pretest PSA and Restaging PSMA PET/CT Predict Survival in Biochemically Recurrent Prostate Cancer.

Background: A biochemical recurrence (BCR) risk model was created based on pretest prostate specific antigen (PSA) and groupings by restaging prostate specific membrane antigen (PSMA) PET/CT.

Methods: A cohort of 1216 BCR patients were analyzed for overall survival (OS) according to the PSA threshold and restaging PSMA PET/CT. A Cox regression analysis of OS was carried out to detect significant clinical characteristics.

Results: In the cohort, 271 patients had a pretest PSA of <0.5 ng/mL and 945 patients had higher PSA values. The restaging PSMA PET/CT was positive for 834 patients and negative for 369. Of 1203 patients, 133 (11%) died, including 19 of the 369 (5%) patients without positive sites on the restaging PSMA PET/CT, 82 of the 711 (12%) with 1-5 positive sites, and 32 of the 123 (26%) with >5 positive sites. In the Cox regression analysis, four variables significantly predicted OS: treatment center, International Society of Urologic Pathology (ISUP) grade, pretest PSA threshold, and the grouping of positive sites on the restaging PSMA PET/CT.

Conclusions: The pretest PSA and PSMA PET/CT were important for the OS of the BCR patients. The findings argue for the new BCR risk model and serve as framework for ongoing trials.