ASCO PROSTATE: Men Reluctant to Chose Active Surveillance for Low Risk Prostate Cancer

KISSIMMEE, Fla., Feb. 22 -- Only 9% of the men whose early prostate cancer was judged to be indolent agreed to active surveillance, an aggressive form of the so-called watchful waiting, urologists reported here today.

The finding reflects what many have long suspected, that active surveillance, meaning regular digital rectal examinations and prostate specific antigen (PSA) testing along with biopsy as needed, is an "under-utilized strategy for managing patients with very low risk disease," said Daniel Barocas, M.D., chief resident in urology at New York-Presbyterian Hospital-Weill Cornell Medical Center.

Sixty percent of the men who met the criteria for active surveillance opted for a radical prostatectomy, 25% chose radiation, and 6% had hormone therapy, Dr. Barocas said during a press briefing at a prostate cancer symposium.

He asserted that active surveillance differs from watchful waiting, which generally follows a hands-off approach with no interventions until a man develops clinical symptoms. By contrast, active surveillance is said to give patients an ongoing, active hunt for subclinical signs of disease.

Dr. Barocas based his findings on an analysis of data from 1,886 men included in the CaPSURE (Cancer of the Prostate Strategic Urologic Research Endeavor) database.

He said that age was a factor in the decision to accept active surveillance -- men ages 63 to 70 are five times more likely to accept this conservative approach than younger men. And the men who were most likely to agree with an active surveillance strategy were men over the age of 70, who were roughly 26 times more likely to chose active surveillance than men younger than 63.

The analysis identified 310 men (16.4% of the total) who met criteria for low risk prostate cancer.

Those criteria include:

• PSA less than 10 ng/ml.
• PSA density of less than 0.15.
• Clinical stage T1 or T2a.
• Gleason score less than or equal to 6, with none 4 or 5.
• Fewer than 33% cores positive on biopsy.

Eric Klein, M.D. professor of surgery and head of urologic oncology at the Glickman urological Institute of the Cleveland Clinic, speculated that most of the patients opted for treatment because even though the risk of the cancer spreading and becoming life threatening was low risk, assessment is not a perfect science.

"We really do not have a good way of predicting in who will get in trouble with this type of cancer," Dr. Klein said. He was not involved in the study.

Dr. Barocas acknowledged that the "positive predictive value of these criteria for identifying indolent cancers that will remain as limited threats ranged from 90% to 94%," which did leave "a lot of uncertainty."

W. Robert Lee, MD, professor of radiation oncology at Duke University in Durham, N.C., who moderated the press conference where the data were discussed, said that age and co-morbidities are major factors in deciding whether to treat or watch. Both factors, he said, were likely to have influenced the outcomes reported by Dr. Barocas.

The American Society of Clinical Oncology, the American Society for Therapeutic Radiology and Oncology, and the Society of Urologic Oncology sponsor the prostate cancer symposium.

The CaPSURE project is managed by the Urology Outcomes Research Group of the University of California, San Francisco Department of Urology. The entire CaPSURE effort is sponsored by TAP Pharmaceutical Products Inc., Lake Forest, Ill.