From Urotoday and the AUA

Of the 2134 PCa cases, 169 (7.9%) had AS as their initial management. Of the 169 AS cases, 89 (53%) remained untreated throughout follow-up (mean 7.1 years) and the remaining 47% received treatment an average of 3.1 years post-diagnosis. Significant predictors of eventual active treatment in multivariate models included younger age at diagnosis (60-69 vs. 70+ years), higher Gleason score (>6 vs. <6), and higher prostate cancer aggressiveness/risk. The researchers observed similar rates for development of clinical metastases and PCa death in both AS and immediate treatment groups, respectively (metastases: N=8 and N=92, 6.5 vs. 6.7 events per 1,000 person-years, p=1.0; PCa death: N=4 and N=51, 2.4 vs. 2.7 deaths per 1,000 person-yrs, p=1.0).

This one study shows that men that did active surveillance, needed therapy about half of the time. The results seemed similar for both groups. My main concern is that we do not know the cancer characteristics of the patients. It is possible that the active surveillance patients had less cancer than the treated patients and should have done better.

I also think that waiting 3 years to treat someone may later the treatment approach and possibly lead to more side effects after therapy.