Low-risk prostate cancer well managed with active surveillance

November 1, 2009

Patients in active surveillance for prostate cancer were almost 20 times more likely to die of causes other than prostate cancer.

Toronto-Patients in active surveillance for prostate cancer were almost 20 times more likely to die of causes other than prostate cancer, according to a Canadian study with more than 13 years of follow-up.

Five of 453 patients have died of prostate cancer since the study began in 1995, Laurence Klotz, MD, reported at the AUA annual meeting in Chicago. The 10-year actuarial prostate cancer survival is 97%.

Patients who opted out of surveillance for definitive therapy had a 10-year biochemical failure rate of 50%, which represented 13% of the overall cohort.

The findings came from the second report from the Sunnybrook Active Surveillance Program. A previous report demonstrated the feasibility of a planned strategy of expectant management and selective delayed intervention in men with low-risk prostate cancer (Can J Urol 2002; 9[suppl]1:2-7).

When the program began, entry criteria included clinical stage T1b-T2b N0 M0, Gleason sum 3+4 or less, and PSA <15.0 ng/mL. In 2000, the Gleason sum threshold was changed to 3+3 and the PSA to <10.0 ng/mL.

In the study, patients have PSA testing every 3 months for the first 2 years and then every 6 months thereafter. Confirmatory 8-to 12-core biopsy is performed after 1 year and then every 3 to 4 years until age 80.

Definitive intervention is offered to patients who have a PSA doubling time less than 3 years, Gleason score progression to 4+3 or higher, or unequivocal clinical progression. The trigger for intervention is individualized by patient age, extent of disease, and the presence of comorbidities, if any, Dr. Klotz said.

After a median follow-up of 6.7 years (range, 1.4–13.3), overall survival was 78%, and 10-year actuarial prostate cancer survival was 97%. Five patients developed metastastatic disease, from which they died.

A total of 135 men had definitive treatment. The most common reason for intervention was a PSA doubling time <3 years (59 patients [44%]) and progression to Gleason 4+3 (32 patients [24%]). Among patients who had had definitive intervention, the PSA failure rate was 70% at 10 years and 52% overall.

The ratio of non-prostate cancer to prostate cancer mortality was 18.6:1.

"This strategy offers the benefit of an individualized approach based on the demonstrated risk of clinical or biochemical progression with time. Thus, it may decrease the burden of therapy in patients with indolent disease, while providing definitive therapy for those with biologically active disease," Dr. Klotz and colleagues concluded.