Active Surveillance of Intermediate-Risk Prostate Cancer Associated With Decreased Survival

By News Release

An analysis of data on 945 patients with prostate cancer that is managed with active surveillance shows differences in outcomes depending on whether the patient was low or intermediate risk at diagnosis. Compared to patients with low-risk disease, those with intermediate-risk cancer (PSA >10ng/ml or Gleason score 7 or clinical stage T2b/2c) had a nearly four-fold higher chance of dying from prostate cancer within 15 years. The study will be presented at the 2015 Genitourinary Cancers Symposium in Orlando, Feb. 26 to 28.

“For low-risk patients with prostate cancer managed with active surveillance, the risk of dying of prostate cancer is low, validating this approach for this group of patients. More research, however, is needed to better characterize those intermediate-risk patients who can safely be monitored on a surveillance program,” said D. Andrew Loblaw, MD, a radiation oncologist at Sunnybrook Health Sciences Centre in Toronto, Canada.

Active surveillance is a globally recognized standard approach for patients with low-risk prostate cancer and select intermediate-risk patients with prostate cancer. Cancer Care Ontario recently released guidelines recommending active surveillance as the preferred approach for low-risk patients. Patients on active surveillance undergo physical examinations, digital rectal examinations, PSA measurements, and repeat tumor biopsies.

According to the authors, this is the first study to examine long-term outcomes of patients with low- vs. intermediate-risk prostate cancer managed on active surveillance.

The researchers analyzed prospectively collected data on 945 patients (237 with intermediate-, 708 with low-risk cancer) who were on active surveillance at Sunnybrook Health Sciences Centre in Canada between 1995 and 2013. Patients whose disease worsened during surveillance were offered treatment (radiation or surgery). In the intermediate risk group, 86 patients received treatment.

The 10-year and 15-year overall survival rates were 68.4 and 50.3 percent for intermediate-risk patients compared to 83.6 percent and 68.8 percent for low-risk patients. The lower survival rate for intermediate-risk patients who were offered active surveillance suggests that these patients had lower life expectancy. Patients with intermediate-risk disease had a 3.75 times higher chance of dying of prostate cancer compared to patients with low-risk disease (11.5 percent vs. 3.7 percent at 15 years, respectively).

This study received funding from the Prostate Cancer Research Foundation (now Prostate Cancer Canada) and internal funding from Sunnybrook Health Sciences Centre.