When Syd Fowler was diagnosed with prostate cancer 15 years ago, he opted for cryotherapy -- the use of subzero temperatures to kill cancer.

Fifteen years later, the 87-year-old McCandless man still golfs, ice skates and lives a cancer-free life.

"I would certainly recommend it," Mr. Fowler said. "In my case it was 100 percent successful."

Mr. Fowler isn't alone in experiencing long-term success with cryotherapy.

Allegheny General Hospital, which pioneered cryotherapy treatment for localized prostate cancer in the early 1990s, has completed a long-term study that shows that it matches the success rates of other minimally invasive therapies including radiation seed implant therapy (brachytherapy) or radiation beam therapy.

Retrospective analysis of 370 patients who underwent cryotherapy 12.5 years ago, on average, showed success rates comparable to more traditional treatments for low- and medium-risk patients and better rates for high-risk cases, or those who had less-than-favorable prognoses.

Study results were published today in the journal Urology.

Dr. Ralph Miller, director of AGH's Prostate Center, said the study proves that cryotherapy "is in the ballpark with other treatments."

"This gives the medical community and patients added confidence," he said.

Co-author Dr. Jeff Cohen, director of AGH's Division of Urology, and Dr. Miller said short-term benefits of cryotherapy are well established, but their landmark study proves for the first time that cryotherapy offers comparable disease-free rates for those who have lived at least 10 years since treatment.

In the early 1990s, Drs. Cohen and Miller were pioneers in refining cryotherapy, a treatment first used in the 1960s. More commonly used nowadays, the therapy remains controversial because of the lack of long-term studies.

But their study, they said, should help to put those controversies to rest.

For those who underwent the treatment more than 12 years ago, the study documents that 80 percent of low-risk patients who received only cryotherapy showed no evidence of recurrence of prostate cancer at least 10 years later, based on regular blood tests. Seventy-four percent of medium-risk patients and 45.5 percent of high-risk patients met that standard.

Cryotherapy offers quicker recovery time compared to standard therapies. It has no radiation toxicity and a quicker delivery time than radiation therapies. Urinary tract complications were generally milder for cryotherapy, but generally it had a greater impact on sexual function than other treatments.

Dr. Cohen noted that the 370 patients in the study underwent treatment in the early years of cryotherapy. Better equipment and added experience should push survival rates even higher.

Prostate cancer is the leading cancer for men of all races in the United States and the second leading cause of cancer death for men. The National Cancer Institute said that more than 215,000 American men are diagnosed each year with prostate cancer and about 27,000 lose their lives to the disease.

Men of all ages, races and ethnic groups are at risk for the disease, but men 55 or older, black men and men whose father or brother have the disease face a higher risk.

Mr. Fowler said his cancer treatment was so successful he gets an annual checkup but no longer worries about a recurrence.

"At 87, I don't worry too much about anything -- just making it through another year," he said.