MARINA DEL REY, Calif--Preliminary studies show that cryosurgical ablation of the prostate can be used to treat localized prostate cancer, resulting in negative post-treatment biopsies and undetectable serum PSA levels, reported Peter R. Carroll, MD, associate professor of urology and director, Urologic Oncology Program, University of California, San Francisco (UCSF).
However, potential candidates for the surgery should be informed that the treatment is moderately morbid, equivalent in cost to standard therapy, and very operator dependent, Dr. Carroll said at a conference jointly sponsored by the UCLA School of Medicine and Clark Urological Cancer Center.
Dr. Carroll attributes the resurgent interest in cryosurgery to improvements and increased expertise in percutaneous techniques, transrectal ultrasound, cryotechnology, and the science of cryobiology. He also said that prospective registration studies of cryotherapy are currently being undertaken, and are clearly needed to fully evaluate the technology.
Results at UCSF
Dr. Katsuto Shinohara and Dr. Carroll have now performed more than 150 cryosurgeries in prostate cancer patients, and Dr. Carroll reported on the results from the first 102 of these patients.
The mean age of the men was 68 years, preoperative PSA values averaged 21.8 ng/mL, and Gleason scores had a mean value of 6.5. Forty-four patients had T1 and T2 lesions, and the remaining 58 had more extensive disease (stage T3 or T4).
In the UCSF study, PSA values at 6 months postcryosurgery were assessed in the 73 patients who received no hormone therapy following the procedure, and who did not have any evidence of nodal or other metastatic disease. PSA was undetectable in 35 men (48%), between 0.1 and 0.5 ng/mL in 22 (30%), and 0.5 or more in the remaining 17 (22%).
"It turns out that if a patient had an undetectable PSA at 6 months, he was likely to maintain that level, at least for the 12 months we've followed up. These results may be better than those for radiation therapy," Dr. Carroll noted.