Medium-term outcomes of active surveillance for localised prostate cancer

Abstract

Background: Active surveillance (AS) aims to allow men with favourable-risk, localised prostate cancer to avoid unnecessary treatment.

Objective: To describe the clinical outcomes of a prospective study of AS.

Design, setting, and participants: A single-centre, prospective cohort study. Eligibility criteria included histologically proven prostate adenocarcinoma, age 50-80 yr, stage T1/T2, prostate-specific antigen level (PSA) <15 ng/ml, Gleason score (GS) ≤ 3+3 (GS ≤ 3+4 if aged >65 yr), and percent positive biopsy cores (PPC) ≤ 50%.

Intervention: Patients were assessed by serum PSA level, and digital rectal examination at 3-mo intervals in year 1, 4-mo intervals in year 2, and at 6-mo intervals thereafter. Transrectal ultrasound-guided prostate biopsy was performed after 18-24 mo and every 2 yr thereafter. Treatment was recommended for PSA velocity (PSAV) >1 ng/ml per year or adverse histology, defined as GS ≥ 4+3 or PPC >50%.

Outcome measurements and statistical analysis: Outcomes described, using Kaplan-Meier methods, were rate of adverse histology on repeat biopsy, freedom from treatment, biochemical control after deferred treatment, and overall survival. Analyses using Cox regression were performed to determine predictors of deferred treatment and adverse histology.

Results and limitations: The study enrolled 471 eligible patients from 2002 to 2011. Median age was 66 yr and median initial PSA value was 6.4 ng/ml. Eighty-eight percent of patients had T1 disease and 93% had GS ≤ 3+3. At median follow-up of 5.7 yr, the 5-yr rate of adverse histology and treatment-free probability was 22% (95% confidence interval [CI], 16-29%) and 70% (95% CI, 65-75%), respectively. There were two deaths from prostate cancer. Predictors of time to adverse histology were GS 7, PSAV >1 ng/ml per year, low ratio of free PSA to total PSA, and PPC >25%. Longer follow-up is needed to confirm the safety of this strategy.

Conclusions: This study demonstrates satisfactory medium-term outcomes for AS in selected men with localised prostate cancer.

Keywords: Active surveillance; Outcomes; Prostate cancer.