Factors Affecting Post-Brachytherapy Urinary Incontinence Type ID'd
TURP and EBRT after seed implantation are associated with development of urge urinary incontinence.
Urinary incontinence (UI) develops in a small percentage of patients with localized prostate cancer (PCa) treated with brachytherapy, a new study confirms. Both pre-treatment and treatment-related factors appear to influence who will experience urge urinary incontinence (UUI) versus stress urinary incontinence (SUI).
For the study, a team led by Simon J. Hall, MD, of Smith Institute for Urology Northwell Health System in Lake Success, New York, identified 2,461 continent men with clinical stage T1-T3 PCa treated with brachytherapy at a single institution during 1990–2011. The real-time transperineal method was used to implant radioactive seeds. Some men also received external beam radiation therapy (EBRT) 2 months after the implant, either as 3D conformal therapy or, more recently, as intensity modulated radiation therapy (IMRT).
At a median 1.8 years, 4.4% of men reported UI, defined as leakage requiring protective pads, according to findings published online ahead of print in Urology. The investigators also observed deterioration in continence after 5 years. A majority of patients (66.7%) used 1 pad daily, 22.2% two, and 11% three or more.
Consistent with other reports, nearly three-quarters had UUI and the remainder had SUI based on self-reports. Multivariate analysis revealed additional risk factors. While post-implantation transurethral resection of the prostate (TURP) was the only significant risk factor associated with SUI, post-implantation TURP, urinary retention, EBRT, and a pre-treatment International Prostate Symptom Score (IPSS) of 7 or higher were significantly associated with UUI.
The prospect of UI highly influences patients' choice of treatment, according to previous research. In this study, incontinent men reported greater declines in quality of life than continent men. There were no significant differences between men with stress- versus urge-predominant UI, however; pad usage was the most impactful.
Use of androgen deprivation therapy (ADT) may affect UI, according to other research, but the current study found no significant influence for neoadjuvant ADT.
“Our findings support urge-related incontinence as the most common mechanism of post-brachytherapy urinary leakage requiring pad usage, which may reflect a contribution of bladder dysfunction as well as sphincteric incompetence,” Dr Hall and colleagues explained. “We would thus hypothesize that late onset of urge incontinence is related to interactions of aging and radiation therapy in the face of factors which predict pre-existing urinary dysfunction such as higher IPSS scores, and larger prostates with or without ADT.”
Continence should be considered a dynamic status in patients undergoing prostate cancer treatment, they added.
Among the study's limitations, UI was self-reported with no urodynamic testing or data on pad weight.