Tissue-Freezing Technique Effective Against Prostate Cancer

By Steven Reinberg
HealthDay Reporter
Wednesday, March 19, 2008; 4:00 AM

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TUESDAY, March 18 (HealthDay News) -- Freezing the prostate to kill cancer, a procedure called cryotherapy, may be as effective as more common treatments such as radiation, U.S. researchers report in the first such follow-up study spanning 10 years.

In this procedure, thin needles are placed into the prostate through which super-cooled argon gas is circulated -- reducing the temperature to up to -150 degrees centigrade. The technique freezes the prostate, killing the cancer it contains.

But the method remains controversial, and is currently the least-used method for treating prostate cancer in the United States.

"One of the reasons cryotherapy is controversial is we didn't know the long-term results," said study co-author Dr. Ralph Miller, director of the prostate center at the Allegheny General Hospital in Pittsburgh. "It really takes 10 years of good follow-up before you can tell how well a treatment works, because prostate cancer typically grows slowly," he said.

The 10-year follow-up study is the first of its kind, Miller noted. It found that clinical outcomes "are basically the same as seed implant radiation and external radiation therapy, the other minimally invasive therapies," he said.

Miller's team reviewed the cases of 370 men who underwent cryotherapy as first-line treatment for various stages of prostate cancer, according to the report in the March issue of Urology.

During an average of 12.5 years of follow-up, the researchers found that men with low-risk prostate cancer had a nearly 81 percent disease-free survival rate after undergoing cryotherapy. In addition, more than 74 percent of men with moderate-risk prostate cancer and almost 46 percent of men with high-risk malignancies experienced disease-free survival over the long follow-up period.

"These findings are confirmation that cryotherapy is another viable treatment option for prostate cancer," Miller said. "There are probably 10- to 15,000 of these procedures done each year in the United States," he noted.