Can active surveillance really reduce the harms of overdiagnosing prostate cancer? A reflection of real life clinical practice in the PRIAS study.

Background: Active surveillance (AS) for low-risk prostate cancer (PCa) appears to provide excellent long-term PCa-specific and overall survival. The choice for AS as initial treatment is mainly based on avoiding side effects from invasive treatment; but AS entails regular check-ups and the possibility of still having to switch or deciding to switch to invasive treatment. Here, we assessed the long-term follow-up data from AS in real life clinical practices.

Methods: Data from the first 500 men, enrolled in PRIAS before July 2008 by 30 centers across 8 countries, were analyzed to provide long-term follow-up results. Men were advised to be regularly examined with prostate-specific antigen (PSA) tests, digital rectal examinations, and prostate biopsies. Men were advised to switch to invasive treatment if they had disease reclassification [Gleason score (GS) ≥3+4 on biopsy, more than two positive biopsy cores, a stage higher than cT2] or a PSA-doubling time of 0-3 years. We assessed time on AS, outcomes and reasons for discontinuing AS, and rates of potential unnecessary biopsies and treatments.

Results: The median follow-up time was 6.5 years. During this period, 325 (65%) men discontinued after a median of 2.3 years and 121 (24%) men had no recent (>1 year) data-update after a median of 7.3 years. The remaining 54 (11%) men were confirmed to be still on AS. Most men discontinued based on protocol advice; 38% had other reasons. During follow-up, 838 biopsy sessions were performed of which 79% to 90% did not lead to reclassification, depending on the criteria. Of the 325 discontinued men, 112 subsequently underwent radical prostatectomy (RP), 126 underwent radiotherapy, 57 switched to watchful waiting (WW) or died, and 30 had another or unknown treatment. RP results were available of 99 men: 34% to 68%, depending on definition, had favorable outcomes; 50% of unfavorable the outcomes occurred in the first 2 years. Of the 30 (6%) men who died, 1 man died due to PCa.

Conclusions: These data, reflecting real life clinical practice, show that more than half of men switched to invasive treatment within 2.3 years, indicating limitations to the extent in which AS is able to reduce the adverse effects of overdiagnosis. Therefore, despite guidelines stating that PCa diagnosis must be uncoupled from treatment, it remains important to avoid overdiagnosing PCa as much as possible.