Active surveillance: the Canadian experience

Active surveillance has evolved to become a standard of care for favorable-risk prostate cancer. This article is a summary of the rationale, method, and results of active surveillance beginning in 1995 with the first prospective trial of this approach.

This was a prospective, single arm cohort study. Patients were managed with an initial expectant approach. Definitive intervention was offered to those patients with a prostate specific antigen (PSA) doubling time of less than 3 years, Gleason score progression (to 4 + 3 or greater), or unequivocal clinical progression. Since November 1995, 450 patients have been managed with active surveillance. Median follow-up is 6.8 years (range 1-16 years). Overall survival is 78.6%. Ten-year prostate cancer actuarial survival is 97.2%. Five of 450 patients (1.1%) have died of prostate cancer. Thirty percent of patients have been reclassified as higher risk and offered definitive therapy. The commonest indication for treatment was a PSA doubling time less than 3 years (48%) or Gleason upgrading (26%). Of 117 patients treated radically, the PSA failure rate was 50%. This represents 13% of the total cohort. Most PSA failures occurred early; at 2 years, 44% of the treated patients had PSA failure. The hazard ratio for nonprostate cancer to prostate cancer mortality was 18.6 at 10 years.

We observed a very low rate of prostate cancer mortality in an intermediate time frame. Among the one-third of patients who were reclassified as higher risk and retreated, PSA failure was relatively common. However, other cause mortality accounted for almost all of the deaths. Further studies are warranted to improve the identification of patients who harbor more aggressive disease in spite of favorable clinical parameters at diagnosis.