Cryoablation outcomes comparable to those of radiation and RP

May 23, 2007

Although a relatively newer treatment for prostate cancer, data from an online database have allowed researchers to evaluate cyroablation as an initial treatment for localized prostate cancer in a meaningful way. Five-year results from the Cryo On Line Database (COLD) Registry suggest that cryoablation has outcomes similar to those seen with radiation therapy and surgery, researchers reported here yesterday.

Although a relatively newer treatment for prostate cancer, data from an online database have allowed researchers to evaluate cyroablation as an initial treatment for localized prostate cancer in a meaningful way. Five-year results from the Cryo On Line Database (COLD) Registry suggest that cryoablation has outcomes similar to those seen with radiation therapy and surgery, researchers reported here yesterday.

The registry comprises information on patients from a large number of hospitals, both community and academic, and the largest number of prostate cryoablation patients to date: 1,198.

Patients were separated into low-, moderate-, and high-risk groups. Patients in the low-risk group had PSAs <10.0 ng/mL, Gleason scores <7, and stage <T2b disease. Patients in the high-risk group had PSAs >20.0 ng/mL, Gleason >7, or stage T2c or greater disease. All other patients were considered moderate risk. Biochemical failure was defined by both the original ASTRO definition (three rises) and the Phoenix 2006 modified definition (nadir +2).

Five-year biochemical survival using ASTRO was 85%, 73%, and 75% for the low-, moderate-, and high-risk groups, respectively. Using Phoenix, the 5-year biochemical survival was 91%, 79%, and 62% for the three groups, respectively. The rectal fistula rate was .4%, and 4.8% of the patients were incontinent (defined as the use of any absorbent pads 12 months after treatment).

The potency rate was 16.8%, with 8.8% able to achieve penetration without any pharmaceutical or device assistance. However, senior author and presenter Stephen Jones, MD, of the Cleveland Clinic, pointed out that the potency rate is low because most patients who are potent prior to treatment are not offered cryotherapy.

An audience member questioned Dr. Jones about the use of ASTRO and Phoenix to measure the results of cryotherapy, since patients were only biopsied if they had a rising or suspicious PSA.

"You're absolutely right, but these are the definitions that are out there," Dr. Jones responded. "One of the goals of the registry is to try to look at patients who have events and to determine what [factors] can tell us patients are going to have events."

The COLD Registry is sponsored by Endocare.