IRCCS Azienda Ospedaliero-Universitaria di Bologna, University of Bologna
Introduction: The objective of this study is to evaluate the oncological outcomes in recurrent prostate cancer (PCa) patients according to PSMA PET/CT results and further salvage treatments guided by PSMA PET/CT findings
Methods: We retrospectively enrolled 240 recurrent Pca patients after radical prostatectomy at 3 European tertiary centers. Patients were stratified according to different clinical settings: group 1, including patients with first biochemical recurrence (BCR, n=143) and group 2, including men with BCR after previous salvage treatments (n=97). Each patient underwent PSMA PET/CT for restaging proposal. Patients in both groups were stratified according to PET results (negative vs. positive). Patients with positive PSMA PET/CT for oligometastatic (= 3 lesions) underwent different type of PSMA-targeted salvage treatment. Patients with positive PSMA PET/CT for polimetastatic (>3 lesions) underwent systemic therapy. Patients with negative PSMA PET/CT were treated with non-imaging guided salvage therapy according to the risk of local or systemic recurrence. Outcome of interest were followings: further BCR and radiologic progression after PSMA PET/CT in group 1, further BCR, radiologic progression and occurrence of castration resistant prostate cancer (CRPC) after PSMA PET/CT in group 2. Oncological outcomes were estimated using Kaplan-Meier curve
Results: In group 1, 68/143 (47.6%) men had positive PSMA PET/CT. Median PSA at PSMA PET/CT was 0.39 ng/ml. Patients with positive PSMA PET/CT had higher median PSA at failure after salvage treatment (p=0.001) and shorter time to BCR (all p=0.01). With a median follow up of 60 months, the BCR-free survival (BCR-FS) and radiologic progression-free survival (rP-FS) at 3-years were 74% vs. 64% and 90% vs. 80% in patients with negative and positive PSMA PET/CT (all p=0.05), respectively. In group 2, 62/97 (64%) men had positive PSMA PET/CT. Median PSA at PSMA PET/CT was 0.7 ng/ml. Men with positive PSMA PET/CT had higher median PSA at PSMA PET/TC. With a median follow up of 92 months, the BCR-free survival (BCR-FS), radiologic progression-free survival (rP-FS) and CRPC-free survival at 3-years was 55% vs. 43% (p=0.2), 80% vs. 56 (p=0.02) and 100% vs. 88 (p=0.02) in patients with negative and positive PSMA PET/CT, respectively
Conclusions: Patients with positive PSMA PET/CT had comparable oncologic outcomes compared to men with negative PSMA PET/CT at time of first BCR and worst oncologic outcomes despite increasing adoption of PSMA-guided treatment in patients with previous salvage therapy.