Selected men with low-risk tumors can benefit from the strategy.
ANAHEIM, Calif.—Active surveillance with delayed intervention is a viable option for well-selected prostate cancer patients with favorable risk, according to researchers at the University of California in San Francisco.
Peter Carroll, MD, and his colleagues characterized disease progression in a subset of men with low-risk malignancy who were enrolled in an active surveillance protocol. Patients underwent repeat prostate needle biopsies at 12-to-24 month intervals and transrectal ultrasound (TRUS) imaging every six to 12 months, and had PSA measurements every three months to track progression.
The researchers defined progression as a change in PSA greater than 0.75 ng/mL per year, an increase in lesion size (as determined by TRUS), or change in Gleason sum. Of the three variables, change in tumor grade was the most significant predictor of delayed intervention, with 35% of the subjects experiencing an increase in Gleason score while on surveillance. No baseline demographic or clinical characteristics accurately predicted disease progression, according to the investigators.
“There are several series of studies starting to show active surveillance is a viable option for men with low-risk disease. The key is that it has to be done in a very careful way, and these men do need to be followed closely,” said researcher Marc Dall’Era, MD, a clinical instructor in the department of urology.
The concept of watchful waiting has changed over time, Dr. Dall’Era said. This approach is being offered to even younger men than in the past. The new findings, which were presented here at the American Urological Association annual meeting, support the notion of offering the approach to men under age 65.
The study enrolled 320 men (mean age 63 years), of whom 71% met all the inclusion criteria for low-risk disease (PSA level below 10 ng/mL, Gleason sum less than 7 with no pattern 4/5, clinical stage T1c-T2a, and percent positive biopsy core under 33%). Of the 320 men, 221 (71%) met all of the above mentioned conditions for low-risk cancers, Dr. Dall’Era said, adding that some men opted for active surveillance despite not meeting all of their strict criteria. The median entry PSA measurement and the median Gleason sum each was 6. The median percent biopsy cores positive for cancer was 13%.
Sixty-eight patients (21%) received treatment after a period of active surveillance, with a median time to treatment of two years, and 41 of the 68 treated patients (71%) had clinical progression. The remaining 29% received treatment despite lack of clinical progression. Stratified by whether they progressed or not, the median time to treatment was two years for men without clinical progression and three years for men with progression.
A total of 52 of the 148 evaluable men (35%) had an increase in Gleason score on surveillance, the investigators reported. A rise in Gleason sum was associated with a threefold increase in the likelihood of treatment. Grade progression was more frequent for men with entry biopsies performed at outside institutions compared with men diagnosed at UCSF (26% vs. 16%).