Active surveillance an evolving approach for low-risk prostate cancer
In this interview, Laurence Klotz, MD discusses his group's active surveillance protocol for men with favorable-risk prostate cancer, which men are candidates, how they are monitored, and triggers for active treatment. Dr. Klotz is professor of surgery at the University of Toronto and chief of urology at Sunnybrook Health Sciences Center, Toronto. He was interviewed by Urology Times Editorial Consultant J. Brantley Thrasher, MD, professor and chair of urology at the University of Kansas Medical Center, Kansas City.
Q: Please give us a brief overview of active surveillance and how you define it.
The concept of expectant management, which we began to pursue about 15 years ago, was based on the idea that microfocal prostate cancer is ubiquitous—part of the aging process—in men. It was obvious that we were increasingly diagnosing this because of PSA-based screening. Thus, treating all patients with low-risk cancer would result in overtreatment of clinically insignificant disease. But we knew that some of these patients harbored worse disease, so the idea of watchful waiting—not giving them any opportunity for cure—was not palatable. We coined the term "active surveillance" as an alternative, with the emphasis on active intervention for the patients who need it based on reclassification to higher risk over time.
The idea is to provide conservative management for the majority and at the same time identify a subset of patients who are harboring more aggressive disease—which we now know is around 25% of patients—based on serial biopsy, serial PSA, perhaps biomarkers, and imaging. Active intervention would be offered to the subset of patients reclassified as having disease with a higher risk for progression.
Q: Who is your optimal candidate for active surveillance based on clinical parameters, and what is the protocol that you're running in Canada right now?
A: When we started this 15 years ago, we included patients with low-risk disease by D'Amico criteria; that is, those with a Gleason score of 6 or less, a PSA of 10 or less, and those with T1c or T2a disease. We also included patients over 70 who had Gleason 3+4 or a PSA between 10 and 15. In 2004, we began to restrict our program to D'Amico low-risk patients, mainly to keep the cohort more homogeneous.
As you know, there's also a very low-risk disease category, which is defined by the Epstein criteria: only one or two positive cores, no core more than 50% involved, and a PSA density less than .15. My view is that is too restrictive and there's quite a lot of data to support that now, so we don't restrict surveillance to those very low-risk patients.
As time has gone by, I've become more inclusive and have stopped treating Gleason 6 cancers. The main significance of higher volume Gleason pattern 3 is that it's been shown by a few groups to be associated with an increased risk of finding Gleason 4 or 5 elsewhere in the prostate. My response to higher volume of Gleason 3 (or 3+3) is to monitor those patients more carefully and biopsy them more frequently, but I still offer them surveillance.