After nearly 7 years of follow-up, cryoablation appears to be as effective as external beam radiation therapy (EBRT) in the treatment of localized prostate cancer, according to the results of a prospective, randomized trial by researchers at the University of Calgary, Alberta, Canada.
No evidence of disease progression—defined as no biochemical evidence of progression, no radiologic evidence of metastasis, and no need for secondary treatment—is the primary efficacy endpoint for the study.
With a median duration of follow-up of 82 months, the rates of no evidence of disease progression in the cryoablation and EBRT groups were 75.7% versus 73.9% at 36 months, 72.7% versus 61.6% at 48 months, and 70.4% versus 58.3% at 60 months. The differences between groups are not statistically significant; however, there is a trend favoring cryoablation over EBRT at 48 months and 60 months, and a statistically significant difference favoring cryoablation over EBRT in the secondary endpoint of persistence of local control at 36 months (negative 10-core transrectal ultrasound-guided biopsy rates, 93.5% vs. 73.3%).
“Controversy continues over what constitutes optimal treatment for localized prostate cancer as there remains a conspicuous lack of randomized trials directly comparing different modalities,” said lead author Bryan J. Donnelly, MD. “Our experience with accrual underlines that such head-to-head studies are difficult, but can be done, and the results from this study to date suggest cryoablation and EBRT can be considered similarly effective.”
