Effectiveness of hochuekkito (Japanese herbal medicine) for general fatigue after introduction of enzalutamide in three cases of castration-resistant prostate cancer

Abstract

(Purpose) Enzalutamide is one of the therapeutic options for castration-resistant prostate cancer (CRPC). However, general fatigue is frequently observed in patients after introduction of enzalutamide. Here, we used the Cancer Fatigue Scale (CFS) to monitor general fatigue after introduction of enzalutamide, and administered the Japanese herbal medicine (Kampo) drug, Hochuekkito, for management of general fatigue. (Materials and methods) Three patients with CRPC were enrolled in this retrospective observational study. The patients were all male, 72, 69, and 88 years old, respectively, and had received previous hormone therapy for CRPC. They complained of general fatigue 2-5 weeks after introduction of enzalutamide. The CFS was divided into three subcategories: physical fatigue, affective fatigue, and cognitive fatigue. Hochuekkito was prescribed for management of general fatigue. Moreover, 31 previous CRPC cases treated in our hospital were divided into a general fatigue group and a non-general fatigue group. The period of enzalutamide prescription was compared among the previous groups and the present three cases to determine the usefulness of Hochuekkito. (Results) In this series, CFS was useful to monitor general fatigue after introduction of enzalutamide. General fatigue after introduction of enzalutamide mainly consisted of physical fatigue, and improved in two of the three cases included in this study. However, enzalutamide was discontinued in one patient due to general fatigue. Fourteen of our 31 previous CRPC cases developed general fatigue after introduction of enzalutamide. The mean periods of enzalutamide prescription were 265.6, 173.2, and 193.0 days in the non-general fatigue, general fatigue, and the present three cases, respectively. The differences among the groups were not significant. (Conclusions) The CFS is useful to monitor general fatigue, including its subcategories, after introduction of enzalutamide in patients with CRPC. The Kampo medicine Hochuekkito may be useful for management of general fatigue in such cases.