Initial PSA levels following salvage cryoabation in prostate cancer patients who failed radiation therapy may predict the likelihood of long-term biochemical progression, researchers found.
In a study, patients with an initial post-cryoablation PSA level below 0.6 ng/mL had a 36-month PSA progression-free survival (BFS) rate (67%), according to a report in BJU International (2010;106:986-990). In contrast, those with an initial post-cryoablation PSA level of 0.6 to 5.0 had a 12-month PFS rate of 50%. In the subjects who had an initial PSA level above 5.0, 64% had PSA progression at six months.
The findings are based on a study of 455 patients selected from the Cryo On Line Data Registry treated with whole gland salvage cryoablation for biopsy proven locally recurrent disease. No patient received hormone therapy. All subjects had initial PSA levels measured 6-12 weeks post-cryoablation.
The researchers, led by David A. Levy, MD, of the Glickman Urological and Kidney Institute at the Cleveland Clinic in Ohio, observed that while these data support the use of a PSA threshold below 0.6 as a potential benchmark of favorable outcomes in the salvage cryoablation population, “they are not intended to represent a definition of treatment success but perhaps one component of a developing definition of such.”
In a separate study of 58 patients who had salvage whole-gland cryoablation following radiotherapy failure, Dr. Levy and colleagues found that lower prostate disease burden—as reflected by the number of positive cores and ratio of positive cores to gland volume—was associated with favorable biochemical outcomes, defined as an initial PSA level below 0.6 at 6-12 weeks post-treatment. Findings were published recently online in Urology.