Skeletal Muscle Loss After Esophagectomy Is an Independent Risk Factor for Patients with Esophageal Cancer

Background: Postoperative changes in skeletal muscle and their influence on outcomes after esophagectomy for patients with esophageal cancer have not been fully investigated. This study aimed to confirm that postoperative skeletal muscle decrease influences long-term patient outcomes. Methods: Data were collected from 218 patients who underwent curative esophagectomy for esophageal cancer whose data were available before and 6 months after surgery. The skeletal muscle index (SMI) was measured at the level of the L3 vertebrae, and the postoperative change in the SMI compared with preoperative values was calculated as the delta SMI. Results: The mean SMI value was − 11.64%, and the median delta SMI value was − 11.88%. The first and third quartiles were defined as cutoffs, and 218 patients were classified as the mild-loss group (54 patients), moderate-loss group (110 patients), and severe-loss group (54 patients). The patients with a more severely reduced SMI had a worse prognosis (5-year overall survival rates: mild loss, 66.6%; moderate loss, 58.8%; and severe loss, 48.5%; p = 0.0314). This correlation between reduced SMI and prognosis also was observed for the patients with preoperative sarcopenia (p < 0.0001), but not for those without preoperative sarcopenia. Conclusions: Postoperative reduced SMI and worse prognosis were significantly associated in esophageal cancer patients.