Body composition changes following chemotherapy for testicular germ cell tumor: obesity is the long-term problem

Metabolic syndrome is a long-term complication of systemic chemotherapy for testicular germ cell tumor (TGCT). It is believed to be caused by secondary hypogonadism or toxic medicines because of orchidectomy followed by systemic chemotherapy. In this study, changes in the body composition of patients over time were quantitatively analyzed up to 24 months after chemotherapy. This study retrospectively analyzed 44 patients with TGCT who underwent chemotherapy at our institution from January 2008 to December 2016. Subcutaneous and visceral fat areas and psoas and skeletal muscle areas were measured by computed tomography before and immediately after chemotherapy as well as 3 months, 6 months, 12 months, and 24 months after chemotherapy. The subcutaneous and visceral fat indices and psoas and skeletal muscle indices were calculated as each area divided by body height squared. The total fat area had already significantly increased 3 months after the initiation of chemotherapy (P = 0.004). However, it did not return to prechemotherapeutic levels even at 24 months after chemotherapy. The skeletal muscle area was significantly decreased at the end of chemotherapy (P < 0.001); however, the value returned to baseline within 12 months. In multivariable analysis, the prechemotherapeutic skeletal muscle index and number of chemotherapy cycles were independently associated with the reduction of skeletal muscle at the end of chemotherapy (P = 0.001 and P = 0.027, respectively). In patients with TGCT, skeletal muscle mass decreased during chemotherapy and recovered within 12 months, whereas fat mass progressively increased from the initiation of chemotherapy until 24 months after chemotherapy.