Outcomes of initially expectantly managed patients with low or intermediate risk screen-detected localized prostate cancer

Study Type - Therapy (outcomes) Level of Evidence 2b What's known on the subject? and What does the study add? Active surveillance aims to reduce overtreatment by selecting patients with low risk prostate cancer (PCa) based on favourable disease characteristics. However, most studies on active surveillance do not have long-term results available; in particular, data on patients with intermediate risk disease are lacking. Our findings demonstrate that withholding radical treatment in men with low or intermediate risk screen-detected localized PCa leads to a substantial delay or even avoidance of radical treatment in a majority of men. Favourable disease-specific outcomes confirm the feasibility of active surveillance for low risk PCa and also support a role for active surveillance in selected patients with intermediate risk PCa. OBJECTIVE To assess the longer-term feasibility of active surveillance, we aimed to evaluate outcomes of patients with screen-detected localized prostate cancer (PCa) who initially elected to withhold radical treatment for either low or intermediate risk disease. PATIENTS AND METHODS All men underwent screening for PCa in the Rotterdam and Helsinki arms of the European Randomized Study of Screening for Prostate Cancer (ERSPC); eligible men were diagnosed with PCa prior to the establishment of the ERSPC-affiliated Prostate Cancer Research International: Active Surveillance (PRIAS) study (19942007) and were initially expectantly managed in the absence of a fixed follow-up protocol. Low risk PCa was defined as clinical stage T1/T2, PSA = 10 ng/mL, PSA density < 0.2 ng/mL/mL, Gleason = 6 and maximum two positive biopsy cores, whereas PSA 1020 ng/mL, Gleason score 7 and three positive biopsy cores were considered intermediate risk features. Disease-specific, overall and treatment-free survival were analysed using the KaplanMeier and competing risks methods. RESULTS In all, 509 patients with PCa were eligible, of whom 381 were considered low risk and 128 intermediate risk. During a median follow-up of 7.4 years, a total of 221 patients (43.4%) switched to deferred treatment after a median of 2.6 years. The calculated 10-year disease-specific survival rates were 99.1% and 96.1% for low and intermediate risk patients, respectively (P= 0.44), and for overall survival 79.0% and 64.5%, respectively (P= 0.003). Competing risks analysis showed similar results. CONCLUSIONS Withholding radical treatment in men with low to intermediate risk screen-detected PCa leads to a substantial delay or even avoidance of radical treatment and its potential side-effects in a majority of patients. Disease-specific outcomes at 7.4 years of follow-up are favourable in low as well as intermediate risk patients. This confirms the feasibility of active surveillance according to contemporary criteria, and also suggests a potential role for active surveillance in selected men with intermediate risk features.