Results of 14 years of brachytherapy for localized prostate cancer in Denmark: the Herlev cohort.

OBJECTIVE: Brachytherapy is one of several curative treatments for localized prostate cancer (PCa). The objective of this study was to report biochemical recurrence-free survival (BRFS), metastatic-free survival (MFS) and PCa-specific mortality after low-dose brachytherapy, stratified according to the D'Amico risk classification in a large Danish cohort. MATERIALS AND METHODS: The study population comprised 502 men treated with brachytherapy in 1998-2012. BRFS was defined by the Phoenix criteria. Kaplan-Meier survival analysis was used to estimate BRFS and MFS. The cumulative PCa mortality was analysed using competing risk analyses. Multivariable Cox regression analysis was used to estimate risk of biochemical recurrence. RESULTS: In total, 206 men were classified with low-risk PCa, 265 men with intermediate-risk PCa and 33 men with high-risk PCa. Median follow-up was 6.6 years [95% confidence interval (CI) 6.2-7.0]. The 10 year BRFS was 90% (95% CI 83-97), 75% (95% CI 65-87) and 75% (95% CI 59-92) in men with low-, intermediate- and high-risk PCa, respectively. The 10 year MFS was 95% (95% CI 89-100), 93% (95% CI 88-98) and 78% (95% CI 57-99) in men with low-, intermediate- and high-risk PCa, respectively. The 10 year cumulative incidence of PCa mortality was 1% (95% CI 0-3), 5% (95% CI 0-12) and 11% (95% CI 0-25) for men with low-, intermediate- and high-risk PCa, respectively. CONCLUSIONS: Low-dose brachytherapy offers good short- to intermediate-term cancer control in selected men with localized PCa. Further studies are needed for safety analyses and for comparison with other treatment modalities.