Event-Free Survival after 68Ga-PSMA-11 PET/CT in recurrent Hormone-Sensitive Prostate Cancer (HSPC) patients eligible for Salvage Therapy.

Abstract Background/AimProstate-Specific-Membrane-Antigen/Positron Emission Tomography (PSMA-PET) detects with high accuracy disease-recurrence, leading to changes in the management of biochemically-recurrent (BCR) prostate cancer (PCa). However, data regarding the oncological outcomes of patients who performed PSMA-PET are needed. The aim of this study was to evaluate the incidence of clinically-relevant events during follow-up in patients who performed PSMA-PET for BCR after radical treatment. Materials and Methodsthis analysis included consecutive, hormone-sensitive, hormone-free, recurrent PCa patients (HSPC) enrolled through a prospective study. All patients were eligible for salvage therapy, having at least 24 months of follow-up after PSMA-PET. The primary endpoint was the Event-Free Survival (EFS), defined as the time between the PSMA-PET and the date of event/last follow-up. The Kaplan-Meier method was used to estimate the EFS curves. EFS was also investigated by Cox proportional hazards regression. Events were defined as: death, radiological progression or PSA recurrence after therapy. ResultsOne-hundred and seventy-six (n=176) patients were analyzed (median PSA 0.62 [IQR:0.43–1.00] ng/mL; median follow-up of 35.4 [IQR:26.5-40.3] months). The EFS was 78.8% at one year, 65.2% (2-years), and 52.2% (3-years). Patients with clinically relevant events had a significantly higher median PSA (0.81 [IQR:0.53-1.28] vs 0.51 [IQR:0.36-0.80] ng/mL) and a lower PSAdt (5.4 [IQR:3.7-11.6] vs 12.7 [IQR:6.6-24.3] months) (p0.5 ng/mL, PSAdt≤6 months and a positive PSMA-PET result were associated with a higher event rate (p 0.5 ng/mL and PSAdt≤ 6months were statistically significant event-predictors in multi-variate model (p<0.001). ConclusionIn this cohort of HSPC patients prospectively enrolled, low PSA and long PSAdt were significant predictors of event. Furthermore, a lower incidence of events was observed also in patients having negative PSMA-PET, since longer EFS was significantly more probable in case of a negative scan.