Introduction

Our institution is a high volume center of radiotherapy for prostate cancer patients (PCaPts). We have performed either neoadjuvant androgen deprivation therapy (NADT), followed by external-beam radiation therapy (total 39 Gray) and high dose-rate brachytherapy (HDR-B, total 18 Gray) (NEH) or radical prostatectomy (RP) on high-risk PCaPts, as defined by prostate specific antigen (PSA) level (>20ng/mL), pathology of biopsy specimen (Gleason score [GS]: ≥8), and/or clinical staging (≥T3). No comparative studies have been reported for NEH and RP. In order to determine if NEH is a better therapy than RP, we compared biochemical recurrence-free survival (bRFS, i.e., post therapeutic PSA elevation) and overall survival (OS) between NEH and RP on high-risk PCaPts.

Methods

Between 2007 and 2012, 192 and 167 high-risk PCaPts were treated by NEH and RP, respectively. Biochemical failure (BF) for NEH was defined using Phoenix definition: any PSA increase of >2 ng/mL higher than the PSA nadir value, regardless of the PSA nadir value. Whereas BF for RP was defined as PSA values of >0.2 ng/mL. Of note, PSA of 18 RP-cases (10.8 %) did not decrease to less than 0.2 ng/mL. In these cases, the day of PSA nadir was defined as BF date. Difference between bRFS and OS were calculated using Kaplan-Meier method and log-rank tests.

Results

The median follow-up duration was 58.7 months. Age was significantly older in NEH group (median [interquartile range] = 71.9 [67.3-75.3] years) than in RP group (69.0 [64.9-72.3] years, p< 0.001, Mann-Whitney U test [MWU]). Initial PSA was higher in NEH (20.0 [10.1-43.6]) than RP group (15.9 [8.1-24.7] ng/dL, p<0.01, MWU). RP group had a trend of higher GS (72.1%) than NEH group (62.5%, p=0.07, chi square test). T stage was similar (NEH [66.1 %] vs RP [66.4 %], p=0.928, chi square test). The 5- and 7-year bRFS rates in NEH group (0.79 and 0.76, respectively) were significantly higher than those in RP group (0.51 and 0.41, respectively, p<0.001 each, Fig. 1A). However, in OS, no significant difference was found (p=0.838).

Conclusions

We retrospectively compared clinical outcomes of NEH and RP, and found that NEH might be as effective as RP for high-risk PCaPts. Currently, we are preparing prospective randomized case study comparing NEH and RP by adjusting age, GS, PSA, and T stage.

Funding

none