Outcomes for active surveillance are similar for men with favourable risk ISUP-2 to those with ISUP-1 prostate cancer: A pair matched cohort study

Objective: To compare medium-term outcomes of active surveillance (AS) for men with favourable risk International Society for Urologic Pathology (ISUP)-2 prostate cancer (PCa) to a pair matched group of men with ISUP-1 PCa. Methods: This was a retrospective analysis of prospectively collected data from a single institution clinical outcomes registry, using propensity score matching. Men enrolled on AS with favourable risk ISUP-2 PCa with minimum 5-year follow-up were 1:2 propensity score matched to men with ISUP-1 disease. We assessed rates of progression to treatment, metastatic disease, adverse surgical pathology and overall survival. Results: Fifty-five ISUP-2 patients were matched to 105 ISUP-1 patients by propensity score. Median follow-up was 81 months (interquartile range (IQR), 61-109 months). Fifty-seven per cent in the ISUP-1 group progressed to treatment versus 58% in the ISUP-2 group (KM log rank p = 0.24). Estimated 1-, 2- and 5-year progression free survival rates were 93%, 60% and 33% for ISUP-1 patients and 94%, 63% and 16% for ISUP-2 patients, respectively. No patient from either group died of PCa. There was no statistical difference in rates of adverse pathology or metastatic disease between ISUP-2 and ISUP-1 patients on AS. Conclusion: AS for carefully selected men with favourable risk ISUP-2 disease appears safe, with similar oncologic outcomes to men with ISUP-1 disease.