Low Prostate Cancer Mortality in Long-Term Follow-up of Canadian Active Surveillance Cohort


Key Points

  • Overall, 1.5% of patients died from prostate cancer.
  • Metastatic disease occurred in 2.8% of patients.

In a study reported in the Journal of Clinical Oncology, Klotz et al found that 1.5% of prostate cancer patients in a Canadian active surveillance cohort died from the disease during up to 16 years of follow-up.

Study Details

The study involved 993 men with favorable-risk prostate cancer who were managed with an initial expectant approach at a single academic health center beginning in 1995. Intervention was offered for prostate-specific antigen (PSA) doubling time of < 3 years, Gleason score progression, and unequivocal clinical progression.

Prostate Cancer Mortality

Among the 819 survivors, median follow-up time from first biopsy was 6.4 years (range = 0.2–19.8 years); 206 patients were followed for > 10 years and 50 for > 15 years. In total, 149 patients (15%) died, 15 (1.5%) due to prostate cancer. The 10- and 15-year actuarial cause-specific survival rates were 98.1% and 94.3%. The cumulative hazard ratio for nonprostate-to-prostate cancer mortality was 9.2 (95% confidence interval = 5.4–15.6).

Metastatic Disease

All patients who died had confirmed metastatic disease before death; an additional 13 patients (1.3%) developed metastatic disease and were alive with confirmed metastases (n = 9) or had died of other causes (n = 4) at the time of analysis.

Overall, 267 patients (27%) were treated for prostate cancer. At 5, 10, and 15 years, 75.7%, 63.5%, and 55.0% of patients remained untreated and on surveillance.

The investigators concluded: “Active surveillance for favorable-risk prostate cancer is feasible and seems safe in the 15-year time frame. In our cohort, 2.8% of patients have developed metastatic disease, and 1.5% have died of prostate cancer. This mortality rate is consistent with expected mortality in favorable-risk patients managed with initial definitive intervention.”

Laurence Klotz, MD, FRCSC, of Sunnybrook Health Sciences Centre, University of Toronto, is the corresponding author for the Journal of Clinical Oncology article.

The study was supported by a grant from the Prostate Cancer Research Foundation of Canada. The study authors reported no potential conflicts of interest.

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.