Published online Aug 24, 2019. doi: 10.5306/wjco.v10.i8.283
Peer-review started: February 27, 2019
First decision: April 11, 2019
Revised: May 5, 2019
Accepted: July 30, 2019
Article in press: July 30, 2019
Published online: August 24, 2019
Processing time: 176 Days and 20.6 Hours
Testosterone level of < 50 ng/dL has been used to define castrate level after surgery or after androgen deprivation treatment (ADT) in metastatic prostate cancer (PC).
To evaluate the effect of two different castrate testosterone levels, < 50 and < 20 ng/dL, on biochemical relapse free survival (BRFS) in patients with non-metastatic intermediate and high risk PC receiving definitive radiotherapy (RT) and ADT.
Between April 1998 and February 2011; 173 patients with intermediate and high risk disease were treated. Radiotherapy was delivered by either three-dimensional-conformal technique to a total dose of 73.4 Gy at the ICRU reference point or intensity modulated radiotherapy technique to a total dose of 76 Gy. All the patients received 3 mo of neoadjuvant ADT followed by RT and additional 6 mo of ADT. ASTRO Phoenix definition was used to define biochemical relapse.
Median follow up duration was 125 months. Ninety-six patients (56%) had castrate testosterone level < 20 ng/dL and 139 patients (80%) had castrate testosterone level < 50 ng/dL. Both values are valid at predicting BRFS. However, patients with testosterone < 20 ng/dL have significantly better BRFS compared to other groups (P = 0.003). When we compare two values, it was found that using 20 ng/dL is better than 50 ng/dL in predicting the BRFS (AUC = 0.63 vs 0.58, respectively).
Castrate testosterone level of less than 20 ng/dL is associated with better BRFS and is better in predicting the BRFS. Further studies using current standard of care of high dose IMRT and longer ADT duration might support these findings.
Core tip: Castrate testosterone level of less than 20 ng/dL achieved after primary radiotherapy plus androgen deprivation treatment for non-metastatic prostate cancer is associated with better biochemical relapse free survival. Testosterone level of < 50 ng/dL has been used to define castrate level after surgery or after androgen deprivation treatment in metastatic prostate cancer (PC). In this study, we evaluated the effect of two different castrate testosterone levels, < 50 and < 20 ng/dL, on biochemical relapse free survival in patients with non-metastatic intermediate and high risk PC receiving definitive modern radiotherapy and androgen deprivation treatment. With a median follow up of 125 mo we found that castrate testosterone level of less than 20 ng/dL achieved after primary radiotherapy plus androgen deprivation treatment was found to be associated with better biochemical relapse free survival.