Analysis of active surveillance uptake for low-risk localized prostate cancer in Canada: a Canadian multi-institutional study.

Purpose: Although the uptake of active surveillance (AS) appears to be increasing in published series, the uptake in most geographic regions remains largely unknown. Our aim was to examine practice patterns around the use of AS in low-risk prostate cancer in Canada. In addition, we examined regional variations in AS uptake, predictors of AS uptake, and persistent use for 12 months.

Methods: This is a retrospective multicentre review of low-risk patients who underwent a prostate biopsy in 2010 in six centres in four provinces (BC, QC, MB and ON). AS was identified based on chart review and required a minimum of 6 months of follow-up after diagnosis without any active treatment.

Results: Of 986 patients, 781 patients (mean age 64 years) were incident cases and over three-quarters (77.3 %) chose AS at diagnosis. There were significant differences in uptake of AS by centre (range 65.0-98.0 %, p ≤ 0.05). Key multivariate predictors of pursuing AS included older age (OR 1.34, p = 0.044), centre (p = 0.021), lower number of cores (OR 1.09, p = 0.025), lower number of positive biopsy cores (OR 0.52, p < 0.001), and lower percent core involvement (OR 0.84, p < 0.001). In total, 516 (85.4 %) men remained on AS over 12 months. Maintenance with AS over 12 months differed by centre, ranging from 64.1 to 93.9 % (p = 0.001). Predictors of maintenance with AS over 12 months included older age, centre, and lower number of positive cores.

Conclusions: Active surveillance is widely practiced across Canada, but important regional differences were observed. Further analyses are required to understand the root causes of differences and to determine whether AS uptake is changing over time.