Dason Shawn, Allard Christopher B, Tong Justin, Shayegan Bobby
Division of Urology, Department of Surgery, McMaster University, Hamilton, ON.
Can Urol Assoc J. 2013 May-Jun;7(5-6):E263-7. doi: 10.5489/cuaj.471.
We seek to determine if testosterone levels below the accepted castration threshold (50 ng/dL) have an impact on time to progression to castrate-resistant prostate cancer (CRPC).
This is a prospective cohort series of patients undergoing androgen deprivation therapy (ADT) with luteinizing hormone-releasing hormone agonist or antagonist at a tertiary centre from 2006 to 2011. Serum testosterone level was assessed every 3 months. Patients with any testosterone >50 ng/dL were excluded. Patients were stratified into groups based on those achieving mean testosterone levels <20 ng/dL and <32 ng/dL. Progression to CRPC was assessed with the Kaplan-Meier method and compared with the log-rank test.
A total of 32 patients were included in this study. Mean patient follow-up was 25.7 months. Patients with a 9-month serum testosterone <32 ng/dL had a significantly increased time to CRPC compared to patients with testosterone 32 to 50 ng/dL (p = 0.001, median progression-free survival (PFS) 33.1 months [<32 ng/dL] vs. 12.5 months [>32 ng/dL]). Patients with first year mean testosterone <32 ng/dL also had a significantly increased time to CRPC compared to 32 to 50 ng/dL (p = 0.05, median PFS 33.1 months [<32 ng/dL] vs. 12.5 months [32-50 ng/dL]). A testosterone <20 ng/dL compared to 20 to 50 ng/dL did not significantly predict with time to CRPC.
This study supports a lower testosterone threshold to define optimal medical castration (T <32 ng/dL) than the previously accepted standard of 50 ng/dL. Testosterone levels during ADT serve as an early predictor of disease progression and thus should be measured in conjunction with prostate-specific antigen.
我们试图确定低于公认去势阈值（50 ng/dL）的睾酮水平是否会对去势抵抗性前列腺癌（CRPC）进展时间产生影响。
这是一项前瞻性队列研究，研究对象为2006年至2011年在一家三级中心接受促性腺激素释放激素激动剂或拮抗剂雄激素剥夺治疗（ADT）的患者。每3个月评估一次血清睾酮水平。排除任何睾酮水平>50 ng/dL的患者。根据平均睾酮水平<20 ng/dL和<32 ng/dL将患者分层。采用Kaplan-Meier方法评估CRPC进展情况，并与对数秩检验进行比较。
本研究共纳入32例患者。患者平均随访时间为25.7个月。血清睾酮水平在9个月时<32 ng/dL的患者与睾酮水平在32至50 ng/dL的患者相比，CRPC进展时间显著延长（p = 0.001，无进展生存期（PFS）中位数：<32 ng/dL组为33.1个月，>32 ng/dL组为12.5个月）。第一年平均睾酮水平<32 ng/dL的患者与32至50 ng/dL的患者相比，CRPC进展时间也显著延长（p = 0.05，PFS中位数：<32 ng/dL组为33.1个月，32 - 50 ng/dL组为12.5个月）。与20至50 ng/dL相比，睾酮水平<20 ng/dL并不能显著预测CRPC进展时间。
本研究支持采用低于先前公认标准50 ng/dL的睾酮阈值来定义最佳药物去势（T <32 ng/dL）。ADT期间的睾酮水平可作为疾病进展的早期预测指标，因此应与前列腺特异性抗原一起进行检测。
