CHARLOTTETOWN, Canada—New findings from a Canadian study support the use of salvage cryotherapy for prostate cancer (PCa) patients who experience disease recurrence after radiation treatment.
Researchers led by Joseph Chin, MD, Chair of the Division of Surgical Oncology at the Schulich School of Medicine & Dentistry at the University of Western Ontario in London, studied 176 patients with biopsy-proven non-metastatic recurrence of PCa following radiation therapy. Subjects underwent transperineal salvage cryotherapy between 1994 and 2004. Of the 176 patients, 52 had more than 10 years of follow-up data. The overall survival rates were 95%, 91%, and 87% at five, eight, and 10 years, respectively, according to data presented at the Canadian Urological Association annual meeting.
Overall, the cohort had a 10-year disease-free survival (DFS) rate of 39%. The researchers observed the highest 10-year DFS rates among men with a pre-salvage PSA level of 5 ng/mL or less (64%) or a pre-salvage biopsy Gleason score below 7 (54%). The rate was 33% for subjects who had a pre-salvage biopsy Gleason score of eight or higher.
“We believe that select patients can benefit from this treatment—that is, those with low PSA,” said co-investigator Andrew Williams, MD, a fellow in the departments of urology and oncology at Schulich, who presented study findings. “We don’t think it is appropriate that patients who have a PSA of more than 10 ng/mL should be given this treatment, as there is such a low chance of cure.”
The 10-year DFS rates were 64%, 31%, and 7% for patients with pre-salvage PSA levels of 5, 5-10, and more than 10 ng/mL, respectively. The 10-year DFS was 54% for patients with a pre-salvage biopsy Gleason score below 7 compared with 33% for patients who had a score of 7 or higher.
The investigators also found that a pre-radiation PSA of 5-10 ng/mL was associated with a fivefold increased risk for PCa recurrence within 10 years of treatment compared with a PSA level of 0-5 ng/mL. A pre-treatment PSA greater than 10 ng/mL was associated with a 5.5 times increased risk.
Additionally, a biopsy Gleason score of 8 or higher was associated with a nearly twofold increased risk of PCa recurrence compared with lower scores. PSA levels of 5-10 and greater than 10 were associated with a 2.8 and 5.1 times increased risk compared with levels of 0-5 ng/mL.