To see whether there were significant differences in outcomes between patients with conservatively managed low- or intermediate-risk disease, the investigators looked at prospectively collected data on 945 men managed with active surveillance at their center from 1995 through 2013. Of this group, 237 had been diagnosed with intermediate-risk disease, defined as a prostate-specific androgen (PSA) level greater than 10, Gleason score of 7, or clinical stage T2b/2c.
Patients were offered intervention if they had a PSA doubling time of less than 3 years, a change in Gleason score, or clinical disease progression.
The authors found that 10-year overall survival (OS) was 67.3% for patients with intermediate risk, compared with 84.2% for those with low-risk disease, and the respective 15-year OS rates were 50.8% vs. 66.7% (hazard ratio, 2.13; P < .0001).
When they looked at cause-specific survival (CSS) rates, they also found significant differences, with a 10-year CSS for intermediate-risk patients of 97.2%, compared with 98.3% for low-risk patients, and 15-year CSS rates of 88.5% vs. 96.7% (HR, 3.74; P = .01).
The investigators concluded that “active surveillance for intermediate-risk prostate cancer has significantly lower overall survival and cause-specific survival, compared with low-risk patients, and therefore extreme caution should be exercised if it were to be implemented in intermediate-risk patients.”
The data are scheduled for presentation in a poster session at the symposium.