Oncologic Outcomes of Incidental Versus Biopsy-diagnosed Grade Group 1 Prostate Cancer: A Multi-institutional Study.

Patients diagnosed with grade group (GG) 1 prostate cancer (PCa) following treatment for benign disease ("incidental" PCa) are typically managed with active surveillance (AS). It is not known how their outcomes compare with those observed in patients diagnosed with GG1 on biopsy. We aimed at determining whether long-term oncologic outcomes of AS for patients with GG1 PCa differ according to the type of diagnosis: incidental versus biopsy detected.

A retrospective, multi-institutional analysis of PCa patients with GG1 on AS at eight institutions was conducted. Competing risk analyses estimated the incidence of metastases, PCa mortality, and conversion to treatment. As a secondary analysis, we estimated the risk of GG ≥2 on the first follow-up biopsy according to the type of initial diagnosis.

A total of 213 versus 1900 patients with incidental versus biopsy-diagnosed GG1 were identified. Patients with incidental cancers were followed with repeated biopsies and multiparametric magnetic resonance imaging less frequently than those diagnosed on biopsy. The 10-yr incidence of treatment was 22% for incidental cancers versus 53% for biopsy (subdistribution hazard ratio [sHR] 0.34, 95% confidence interval [CI] 0.26-0.46, p < 0.001). Distant metastases developed in one patient with incidental cancer versus 17 diagnosed on biopsy and were diagnosed with molecular imaging in 13 (72%) patients. The 10-yr incidence of metastases was 0.8% for patients with incidental PCa and 2% for those diagnosed on biopsy (sHR 0.35, 95% CI 0.05-2.54, p = 0.3). The risk of GG ≥2 on the first follow-up biopsy was low if the initial diagnosis was incidental (7% vs 22%, p < 0.001).

Patients with GG1 incidental PCa should be evaluated further to exclude aggressive disease, preferably with a biopsy. If no cancer is found on biopsy, then they should receive the same follow-up of a patient with a negative biopsy. Further research should confirm whether imaging and biopsies can be avoided if postoperative prostate-specific antigen is low (<1-2 ng/ml).

We compared the outcomes of patients with low-grade prostate cancer on active surveillance according to the type of their initial diagnosis. Patients who have low-grade cancer diagnosed on a procedure to relieve urinary symptoms (incidental prostate cancer) are followed less intensively and undergo curative-intended treatment less frequently. We also found that patients with incidental prostate cancer are more likely to have no cancer on their first follow-up biopsy than patients who have low-grade cancer initially diagnosed on a biopsy. These patients have a more favorable prognosis than their biopsy-detected counterparts and should be managed the same way as patients with negative biopsies if they undergo a subsequent biopsy that shows no cancer.

European urology open science. 2024 Aug 20*** epublish ***

Riccardo Leni, Emily A Vertosick, Roderick C N van den Bergh, Timo F W Soeterik, Joris G Heetman, Harm H E van Melick, Marco Roscigno, Giovanni La Croce, Luigi F Da Pozzo, Jonathan Olivier, Fabio Zattoni, Matteo Facco, Fabrizio Dal Moro, Peter K F Chiu, Xiaobo Wu, Isabel Heidegger, Giulia Giannini, Lorenzo Bianchi, Luca Lampariello, Leonardo Quarta, Andrea Salonia, Francesco Montorsi, Alberto Briganti, Umberto Capitanio, Sigrid V Carlsson, Andrew J Vickers, Giorgio Gandaglia, EAU-YAU Prostate Cancer Working Group

Division of Experimental Oncology, Department of Urology, IRCCS San Raffaele Scientific Institute, Milan, Italy., Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Department of Urology, St. Antonius Ziekenhuis, Nieuwegein, The Netherlands., Department of Urology, ASST Papa Giovanni XXIII, Bergamo, Italy., Department of Urology, Lille University, Lille, France., Department of Surgery, Oncology and Gastroenterology, Urology Clinic, University of Padua, Padua, Italy., Division of Urology, Department of Surgery, SH Ho Urology Centre, The Chinese University of Hong Kong, Hong Kong, Hong Kong., Department of Urology, Medical University Innsbruck, Innsbruck, Austria., Division of Urology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, University of Bologna, Bologna, Italy.