ORLANDO—Younger sexually active men are more likely to experience PSA bounce after undergoing brachytherapy for localized prostate cancer (PCa), Japanese researchers reported at the American Urological Association 2014 annual meeting.
Masashi Matsushima, MD, and colleagues at Keio University School of Medicine in Tokyo, studied 157 patients who had a median follow-up of 31 months. Of these, 39 experienced PSA bounce at a median follow-up of 18 months after implantation. A higher International Index of Erectile-15 (IIEF-15) score at 12 months and age younger than 70 years significantly predicted PSA bounce. In multivariate analyses, only total IIEF-15 score at the time of PSA remained statistically significant.
The investigators defined PSA bounce as a PSA rise of 0.4 ng/mL or greater above an initial PSA nadir followed by a subsequent decline to or below the initial nadir.
At 12 months after treatment, the mean total IIEF-15 score was 28.1 in the PSA bounce group compared with 17.8 in the men who did not have PSA bounce.
Thirty-one of the 39 men in the PSA bounce group (79.4%) were younger than 70 years compared with 55 of the 118 patients (46.6%) in the group that did not experience PSA bounce.
The PSA bounce group had a higher erectile function domain score, higher orgasm function domain score, higher sexual desire domain score, and higher total IIEF-15 score after brachytherapy than patients who did not have PSA bounce.
A total of 30 PSA bounce patients completed the IIEF-15 questionnaire at the time of PSA bounce and 56 non-PSA-bounce patients completed the questionnaire at 18 months after brachytherapy (equivalent to the median time of PSA bounce). Multivariate analyses of data from this group of 86 patients showed that only total IIEF-15 score at the time of PSA bounce remained a statistically significant predict of PSA bounce.
The researchers concluded in their poster presentation that “abundant post-treatment sexual activity influences PSA bounce.”