Primary tumour PSMA intensity is an independent prognostic biomarker for biochemical recurrence-free survival following radical prostatectomy
Matthew J. Roberts, Andrew Morton, Nathan Papa, Anthony Franklin, Sheliyan Raveenthiran, William Yaxley, Geoffrey D. Coughlin, Troy Gianduzzo, Boon Kua, Louise McEwan, David Wong, Brett Delahunt, Lars Egevad, Hemamali Samaratunga, Nicholas Brown, Robert Parkinson, Louise Emmett, John Yaxley
Abstract
PURPOSE: The prognostic value of PSMA intensity on PSMA PET/CT due to underlying biology and subsequent clinical implications is an emerging topic of interest. We sought to investigate whether primary tumour PSMA PET intensity contributes to pre- and post-operative prediction of oncological outcomes following radical prostatectomy. METHODS: Ga-PSMA PET/CT prior to radical prostatectomy. PSMA intensity, quantified as maximum standard uptake value (SUVmax), and other clinical variables were considered relative to post-operative biochemical recurrence-free survival (BRFS) using Cox regression and Kaplan-Meier analysis. RESULTS: After a median follow-up of 41 months, 219 events occurred; the estimated 3-year BRFS was 79% and the 5-year BRFS was 70%. Increasing PSMA intensity was associated with less favourable BRFS overall (Log rank p < 0.001), and within subgroups of Gleason score category (Log rank p < 0.03). PSMA intensity was significantly associated with shorter time to biochemical recurrence, after adjusting for pre-operative (HR per 5-unit SUVmax increase = 1.15) and post-operative (HR per 5-unit SUVmax increase = 1.10) parameters. CONCLUSION: These results in a large series of patients confirm PSMA intensity to be a novel, independent prognostic factor for BRFS.