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Brachytherapy for prostate cancer treatment may induce secondary bladder cancer during long-term follow-ups. This study reviews the risk and tumor characteristics of secondary bladder cancer after brachytherapy.This single-institution retrospective study included 1162 patients treated with low-dose-rate permanent seed implantation brachytherapy with iodine-125, with or without external beam radiation therapy, for localized prostate cancer. We calculated and compared the rates of secondary bladder cancer among patients treated with brachytherapy and radical prostatectomy (n = 218) before and after a propensity score-matching analysis. Possible risk factors for secondary bladder cancer, such as patient age and external beam radiation therapy administration, were analyzed.Of 1162 patients with a median follow-up period of 11.4 (range: 0.7-15.5) years, 26 presented with urothelial carcinomas and 1 with adenocarcinoma at a median of 8.9 (range: 2.9-14.0) years after brachytherapy, although the incidence rates of secondary bladder cancer after brachytherapy were not significantly different from those after radical prostatectomy. No significant risk factors for secondary bladder cancer were identified. The initial symptoms of secondary bladder cancer were gross hematuria (74%) and microscopic hematuria with positive urine cytology (15%). Among 26 cases of secondary urothelial carcinoma, 54% were high-grade and 46% were invasive. After brachytherapy, invasive urothelial carcinoma occurred later than noninvasive urothelial carcinoma (p = 0.01).Considering the aggressive malignancy of secondary bladder cancer, cystoscopy and urine cytology should be performed for further investigation of the causes of gross or microscopic hematuria and rule out secondary bladder cancer in cases followed longer than 3 years after brachytherapy.

Purpose The purpose of the study was to evaluate the effect of adding androgen deprivation therapy (ADT) to brachytherapy with or without external beam radiation therapy on oncological outcomes in prostate cancer. Methods and Materials Overall, 1,171 patients with intermediate-risk prostate cancer treated with brachytherapy with or without external beam radiation therapy with or without ADT between 2003 and 2013 were identified. Propensity score matching was used to counter biases between the ADT and non-ADT groups. The biochemical failure-free rate (bFFR), local recurrence-free rate, and overall survival rate were evaluated using Kaplan–Meier curves, and predictors were identified using Cox proportional hazards regression models. Results After propensity score matching, 405 patients were included in each group. The median followup duration was 9.1 years; the median ADT duration was 6 months. In the ADT versus non-ADT groups, the 9-year bFFR, local recurrence-free rate, and overall survival rate were 93.4% versus 87.8% (p = 0.016), 96.9% versus 98.1% (p = 0.481), and 88.1% versus 90.4% (p = 0.969), respectively. On multivariate analyses, Gleason score (hazard ratio [HR]: 2.52, 95% confidence interval [CI]: 1.58–4.03) and ADT use (HR: 0.55, 95% CI: 0.34–0.89) were associated with biochemical failure. Supplemental external beam radiation therapy use (HR: 0.38, 95% CI: 0.16–0.91) was associated with lower local recurrence rates. Age (HR: 1.12, 95% CI: 1.08–1.16) and comorbidities (HR: 1.56, 95% CI: 1.04–2.34) were associated with all-cause mortality. Conclusions A risk-benefit assessment between bFFR improvement and the potential side effects of adding ADT to brachytherapy-based radiotherapy is warranted before incorporating ADT as routine practice.