PD10-08: The Prognostic Impact of Preoperative PSMA-PET on Early Oncological Outcomes in Prostate Cancer Patients Treated with Radical Prostatectomy: Results of a Multi-center Analysis
Introduction: PSMA-PET in prostate cancer (PCa) staging is associated with higher accuracy for nodal and metastatic detection than conventional imaging. Clinical guidelines still do not recommend PSMA-PET before radical prostatectomy (RP). We hypothesized that the implementation of PSMA PET in the preoperative staging pathway is associated with better patient risk stratification and early cancer control. Methods: We relied on 3,978 N0M0 PCa patients treated with RP +/- extended pelvic nodal dissection between 2010 - 2022. 3,518 men staged with conventional imaging were identified in a single institution dataset (Group 1). Additional 278 patients with available details both on PSMA PET and CT scans were identified from a multi-institutional cohort of men staged with PSMA-PET (Group 2). Early recurrence was defined as PSA persistence (first postoperative PSA =0.1 ng/ml) or PSA rise =0.2 ng/ml within 1 year after RP. Multivariable logistic regressions (MLR) tested the impact of the preoperative imaging on early recurrence. MLR models tested for predictor status of PET-PSMA and CT-scan after adjusting for PSA, biopsy grade group and non-organ-confined (NOC) disease at mpMRI. Accuracy of MLR models containing PET-PSMA (model 1) and CT-scan (model 2) were assessed with the ROC-derived AUC. Decision-curve analyses (DCA) assessed the net benefit associated with the use of the two models. Results: 282 patients experienced early recurrence. Patients in Group 2 had higher preoperative PSA values (8.5 vs. 6.4 ng/mL) and higher rates of biopsy grade group (GG) >3 (57% vs. 11%, all p <0.01) compared to Group 1. Early BCR rates were similar between the two groups (12% vs. 10% for group 2 and group 1, respectively, p=0.3). At MLR, being staged with PSMA-PET was associated with a lower risk of early recurrence (OR 0.61, p=0.01) after accounting for PSA, clinical stage, and biopsy ISUP GG. Focusing on men with available PSMA-PET and CT, the presence of positive PET-PSMA (OR: 4.34, p=0.004) but not CT-scan predicted early recurrence. The discrimination was higher for model 1 including PSMA-PET compared to model 2 (73 vs 67%). The adoption of model 1 including PSMA-PET was associated with a higher net benefit as compared to model 2. Conclusions: Non-metastatic PCa patients staged with PSMA PET scan are at lower risk of early recurrence when compared to those staged with conventional imaging alone. PSMA PET scan helps clinicians to improve preoperative risk stratification and to the identification of men who might benefit most from treatments. SOURCE OF Funding: None
