Detalle de: Serum Luteinizing Hormone Testing Can Identify Optimal Medical Castration

Prostate cancer (PCa) guidelines recommend serum testosterone testing to assess theefficacyof castrationand todefine castration resistance when biochemical or clinical progression is detected. The currently accepted serum testosterone castrate level is 50 ng/dl, although levels below 20 ng/dl have been associated with longer castration resistance–free survival [1]. This castrate level of serum testosterone was established during the 1980s by the US Food and Drug Administration to evaluate products for castration. It arose from previous studies on PCa patients who had undergone surgical castrationandcorrespondedto the lowest sensitivity level of the radioimmunoassays available [2]. In 2007, on the basis of previous studies [3,4], the American Endocrine Society and the Centers for Disease Control and Prevention recommended only methods based on mass spectrometry to measure testosterone, especially for the low levels detected in women and children [5]. In 2016, we highlighted that chemiluminiscence was used in all clinical studies analyzing the prognostic value of serum testosterone. Chemiluminiscent assays are the methods most used in clinical laboratories owing to high sensitivity, automatability, high speed, and low cost; however, their lack of accuracy and reproducibility at low levels make these results uncertain [6]. We have observed discrepancies in serum testosterone results from different chemiluminiscent assays [7] and we have suggested mass spectrometry as the appropriate method for measuring serum testosterone in PCa patients undergoing medical castration [8]. Finally, we have observed that serum luteinizing hormone (SLH) is better associatedwithmedical castration activity than serum testosterone is, even when measured with an appropriate method. We established a castrate level of SLH as 1.10 UI/l [9]. SLH has also been used to monitor the switch between luteinizing hormone– releasing hormone (LH-RH) antagonist and agonist [10]. The aim of the present study was to analyze the