Freezing Shows Promise in Treating Prostate Cancer

By literally freezing prostate cancer cells to death, radiologistscan effectively treat prostate cancer in some patients while reducingcomplication rates, preliminary results of a study show. The newprocedure, trans- rectal ultrasound-guided cryoablation, alsocosts less than traditional prostate cancer treatments, the studyindicates.

Of the 310 men treated with the technique so far, 90% have hadnegative biopsies, said Dr. Duke Bahn, chair of the Departmentof Radiology at Crittenton Hospital in Rochester, Michigan. Follow-upof these patients ranged from 3 months to 2 years, Dr. Bahn toldthe American Roentgen Ray Society at its annual meeting in Washington,D.C.

Patients with cancer confined to the prostate gland or those whosecancer has spread near the gland are candidates for the freezingprocedure, said Dr. Bahn. Probes are inserted through small skinpunctures into the prostate gland. Liquid nitrogen is circulatedthrough the probes and the entire prostate is frozen. When theprostate thaws, the cells rupture and die, he said. "Thefreezing process is carefully monitored by high resolution ultrasoundto avoid injuries to adjacent organs," said Dr. Bahn. Patientsusually are only in the hospital overnight, and they can returnto their normal routine in about 2 weeks.

The cost of cryoablation is about one-third to one-half that ofsurgery or radiation therapy, Dr. Bahn noted. Complication ratesappear to be much lower than rates associated with surgery. Forexample, incontinence occurs in at least 30% of patients who undergosurgery. "Our incontinence rate is only 1%," said Dr.Bahn.

The cryoablation procedure can be repeated if it fails, said Dr.Bahn. Patients also can choose to undergo radiation therapy orsurgery if cryoablation proves ineffective, he added.

"We are very optimistic about this procedure," saidDr. Bahn. However, he cautioned, long-term clinical trials needto be done to determine whether this treatment increases overallsurvival. Transrectal ultrasound-guided cryoablation is availablein about 100 institutions across the United States.