Active surveillance may be a viable option for some men, but reclassification of disease risk over time is imperative to ensure outcomes, according to researchers in Toronto, who will present these criteria during the 104th Annual Scientific Meeting of the American Urological Association (AUA).
Active surveillance can offer prostate cancer patients the benefit of an individualized approach based on reclassification of the risk of disease progression over time. Active surveillance using carefully defined criteria can decrease the burden of therapy in patients with slow growing disease, while providing definitive therapy for those with more aggressive disease.
Active surveillance is typically offered to men with slow-growing prostate cancer that may not progress within their lifetime. In other words, the cancer is not likely to be fatal and treatment might cause unnecessary adverse effects. Patients on active surveillance undergo periodic screenings to determine disease progression or risk.
This abstract represents data from the second phase of this study, which was initiated in 1995. Since then, researchers have studied 453 active surveillance candidates to determine the best intervention parameters (at what point physicians should intervene and offer more aggressive treatment options). Study results show that patients who experience a prostate-specific antigen (PSA) doubling time of less than three years or a pathologic progression to Gleason 4+3 are at a higher risk for disease progression and require more aggressive treatment.
In the initial stage of the study, researchers offered active surveillance to prostate cancer patients with favorable risk parameters (Gleason less than or equal to 6, and PSA less than or equal to 10) as an alternative to radical treatment. Patients were followed with serial PSA testing and periodic biopsy. Intervention was offered based on PSA kinetics or grade progression. In 2000, the study was restricted to favorable risk disease. Definitive intervention was offered to those patients with a PSA doubling time of less than three years, Gleason score progression (to 4+3 or greater) or unequivocal clinical progression.
Of the 453 patients on the program, the median age is currently 70, the median follow-up is 7.2 years, the overall survival is 83 percent and the prostate cancer survival is 99 percent. Five of the 453 patients have died of prostate cancer; 35 percent have been reclassified as higher risk and offered definitive therapy. The most common indications for treatment were a PSA doubling time of less than three years or Gleason upgrading. Of the 137 patients treated surgically, the PSA failure rate (rising PSA) was 52 percent. Patients with biochemical failure after radical therapy constitute 15 percent of the overall study group. The ratio of non-prostate cancer to prostate cancer mortality was 16.
"In terms of evaluating the outcome from any prostate cancer therapy or watchful waiting protocol, the duration of observation is critical. Although 7.2 years of follow-up, as noted here, seems long, many investigators would be careful with any conclusions until the follow-up time exceeded 10 years," said Kevin T. McVary, MD, an AUA spokesman. "Regardless, watchful waiting is an appropriate and commonly practiced care for selected men with prostate cancer."