Active Surveillance for Low- and Favourable Intermediate-Risk Prostate Cancer: A Single-Centre Cohort Study on Discontinuation Rates and Quality-of-Life Outcomes

Background: Active surveillance (AS) represents a cornerstone of personalized medicine in uro-oncology, offering an individualized management strategy for low- and selected favourable intermediate-risk prostate cancer that aligns treatment intensity with patient-specific risk profiles; however, real-world adherence data from southern European academic centres remain scarce. This study aimed to evaluate AS discontinuation rates, reasons for transition to active treatment, and quality of life (QoL) in a single-centre Greek university hospital cohort. Methods: This is an observational retropective cohort study of patients enrolled in an AS protocol at the First Department of Urology, Aristotle University of Thessaloniki, between October 2016 and July 2022. Treatment-free survival (TFS) was estimated using Kaplan–Meier analysis. Associations between AS discontinuation and age at diagnosis, PSA level, and Charlson Comorbidity Index (CCI) were explored using univariable and multivariable Cox proportional hazards regression. QoL, erectile function, and anxiety were assessed cross-sectionally in patients remaining on AS using SF-12, IIEF-6, STAI-6, and MAX-PC. Results: Thirty-six patients were included (32 low-risk; 4 favourable intermediate-risk), with a median age of 69.5 years, median PSA of 6.92 ng/mL, and median CCI of 3. After a median follow-up of 24 months (IQR 21–45), 19 patients (52.8%) transitioned to active treatment; the median time to treatment was 21 months (IQR 17–34). Among the 10 patients with a known reason for discontinuation, 6 (31.6% of all discontinued) showed histopathological or clinical disease progression, 3 (15.8%) had a PSA increase alone, and 1 (5.3%) transitioned due to urinary symptoms; the reason was unknown in 9 cases (47.4%). In exploratory Cox regression, PSA ≥ 7.0 ng/mL was the only factor with complete documented output significantly associated with transition to active treatment (univariable HR 3.70, 95% CI 1.35–10.1, p = 0.011; multivariable HR 3.93, 95% CI 1.42–10.9, p = 0.008). Cross-sectional QoL assessment in 10 patients remaining on AS demonstrated median scores above established population norms for SF-12 and below clinical anxiety thresholds on STAI-6 and MAX-PC. Conclusions: In this single-centre cohort, AS discontinuation occurred early and at a rate higher than that of established international programmes, consistent with the institution’s initial AS experience. Higher PSA at diagnosis was the only factor with complete analytical documentation to be significantly associated with earlier transition.