Introduction

High-dose-rate brachytherapy (HDR) with external-beam radiotherapy (EBRT) combined with long-term androgen deprivation therapy (ADT) and radical prostatectomy (RP) are common treatment options for high-risk prostate cancer (PC). We retrospectively evaluated the mid-term outcomes of both treatment groups and compared the rates of biochemical recurrence (BCR) and clinical progression-free survival (CPFS).

Methods

Between 2004 and 2014, 589 patients with high-risk PC underwent RP (n = 302) or HDR (n = 287). RP included extended lymph node dissection. HDR was performed with EBRT and/or neoadjuvant and long-term adjuvant ADT. The definition of BCR for each treatment was different, namely prostate specific antigen (PSA) level 0.2 ng/mL for RP and PSA nadir plus 2 (Phoenix definition) for HDR. Kaplan-Meier analyses and multivariable Cox regression analyses were performed to predict BCR and CPFS.

Results

The median follow-up times of RP and HDR were 49 and 52 months, respectively. Patients who underwent HDR were significantly older (P < 0.001), had higher mean initial PSA levels (P < 0.001), higher clinical T stage (P = 0.093), and higher mean biopsy Gleason score (P < 0.001). Five-year BCR free survival was significantly better after HDR than RP (80.1% vs. 62.9%; P < 0.001). However, there was no significant difference in the 5-year CPFS between HDR and RP groups (88.9% vs. 91.8%; P = 0.68). After RP, 64.6% (195/302) of patients required no additional treatment. In multivariate analysis, clinical T stage (P < 0.01) and biopsy Gleason score (P < 0.01), but not modality (P=0.749), were significant predictive factors of CP.

Conclusions

In this 10-year investigation at our institute, patients who underwent HDR had worse pre-treatment characteristics; however, had better BCR-free survival than patients who underwent RP. However, CPFS was not significantly different between patients who underwent either of the treatments.

Funding

none