Predictors of changes in skeletal muscle mass after esophagectomy in elderly patients with esophageal cancer

Abstract Purpose : Although a change in skeletal muscle mass index (SMI) 4 months after esophagectomy impacts prognosis, predictors of a change in SMI have not been revealed. The purpose of this exploratory retrospective study was to clarify the predictors of a change in SMI after curative esophagectomy in elderly patients with esophageal cancer.Methods : Fifty-four patients who underwent esophagectomy and perioperative rehabilitation from 2015 to 2018 were enrolled. Preoperative and postoperative SMI (cm 2 /m 2 ) were calculated using computed tomography images. The ratio change in SMI was calculated as follows: (postoperative SMI − preoperative SMI) ÷ preoperative SMI × 100%. Potential predictors of a change in SMI ratio were analyzed by multiple regression. Results : The mean ratio change in SMI 4 months after esophagectomy was −7.1% ± 9.4%. The ratio change in quadriceps muscle strength in the first month after surgery ([postoperative strength − preoperative strength] ÷ preoperative strength × 100%) (standardized β = .273, p = .038) and neoadjuvant chemotherapy (NAC) (standardized β = .398, p = .006) were predictors of the ratio change in SMI independent of age, sex, pathological stage, and preoperative SMI. Conclusion : Quadriceps muscle weakness in the first month after esophagectomy and NAC were predictors of the ratio change in SMI after esophagectomy. Continuous postoperative comprehensive rehabilitation and supportive care may inhibit loss of skeletal muscle mass.