Combined brachytherapy and external beam therapy (EBRT) is associated with a high rate of five-year biochemical failure-free survival in men with high-risk prostate cancer (PCa), according to a Japanese study.
The study included 206 patients with high-risk PCa treated with iodine-125 brachytherapy and EBRT. Of these, 101 (49%) also received neoadjuvant androgen deprivation therapy (ADT), but no patient received adjuvant ADT. The patients had a median follow-up of 60 months.
The cohort had a five-year biochemical failure-free survival (BFFS) rate of 84.8%, the investigators reported online ahead of print in Radiation Oncology. The five-year cancer-specific and overall survival rates were 98.7% and 97.6%. Eight patients (3.9%) died, two from PCa.
The investigators, led by Toshio Ohashi, MD, of Keio University School of Medicine in Tokyo, defined high-risk PCa patients as those with a PSA level of 20 ng/mL or higher and/or a Gleason score of 8 or higher, and/or stage T3 or higher cancer.
On multivariate analysis, positive biopsy core rates and the number of high-risk factors independently predicted BFFS. The five-year BFFS rate was 89.3% for patients with less than 50% positive cores compared with 78.2% for those with 50% or more positive cores. The rate was 86.1% for patients with any single high-risk factor compared with 73.6% for those with two or three high-risk factors. Neoadjuvant ADT did not affect five-year BFFS.