Endocrinological Changes after Anamorelin Administration in Patients with Gastrointestinal Cancer

Changes in hormone levels in patients with cancer cachexia after anamorelin administration have not been fully investigated. This study aimed to determine how anamorelin affects the endocrine system in patients with gastrointestinal cancer and cachexia. We prospectively enrolled 13 patients and comprehensively investigated their body weight and levels of serum albumin, hemoglobin A1c (HbA1c), and hormones before (week 0) and 3 and 12 weeks after anamorelin administration. The variables were evaluated at week 3 in 9 patients and at week 12 in 5 patients. At week 3, anamorelin administration resulted in body weight gain and increased the levels of growth hormone and HbA1c, as well as insulin-like growth factor-1 standard deviation scores (IGF-1 SD scores). At the same time, negative correlations were observed between ΔIGF-1 SD score and Δthyroidstimulating hormone (TSH) and between ΔIGF-1 SD score and Δfree testosterone. ΔBody weight and ΔIGF-1 SD score correlated positively at week 12. These results suggest that TSH and free testosterone levels can be affected 3 weeks after anamorelin administration; however, those variables tend to return to a state of equilibrium, and anabolic effects of anamorelin appear in long-term (≥ 12 weeks) users.