A prospective study of the relationship between CRPC patient’s quality of life after enzalutamide and serum testosterone levels measured via LC-MS/MS.

Abstract

79 Background: Enzalutamide (ENZ) is used to treat patients with castration-resistant prostate cancer (CRPC). Quality of life (QOL) during ENZ treatment for CRPC patients is very important, but the markers that predict QOL are unknown. We investigated the relationship between serum testosterone (T) levels before ENZ and QOL changes in CRPC patients. Methods: We conducted a prospective study from 2014 to 2018 at Gunma University Hospital and related facilities. We analyzed 95 patients who were able to evaluate QOL by FACT-P before, 4 weeks, and 12 weeks after ENZ administration. We measured serum T levels using liquid chromatography-tandem mass spectrometry (LC-MS/MS). This study was approved by the institutional review board of Gunma University Hospital (No.1177). Results: The study population of 95 patients had a median age of 72 years and median PSA of 21.6 ng/ml. The median overall survival from the time of ENZ administration in 95 cases was 26.8 months. The median serum T levels before ENZ treatment was 50.0 pg/ml. The mean total FACT-P score before ENZ administration, 4 weeks and 12 weeks later were 95.8, 91.7, and 90.1, respectively. 95 patients were divided into two groups, a high T levels (T-High) group and a low T (Low-T) group, and changes in FACT-P were examined. The mean FCAT-P values in the High-T and Low-T groups were 98.5 and 84.6 after 4 weeks and 96.4 and 82.2 after 12 weeks, which were significantly higher in the High-T group (p < 0.05, respectively). In the Low-T group, the mean FACT-P value after 12 weeks was significantly lower than that before administration (p < 0.05). Conclusions: It was suggested that the serum T levels of CRPC patients before ENZ treatment may be useful for predicting marker of QOL changes after ENZ treatment.