Prognostic Significance of Skeletal Muscle Loss During Early Postoperative Period in Elderly Patients with Esophageal Cancer

Background Skeletal muscle loss during the early postoperative period frequently occurs during post-esophagectomy. Preoperative sarcopenia is a known prognostic factor. However, the prognostic significance of postoperative skeletal muscle loss remains unclear. This study was designed to clarify the impact of skeletal muscle loss during the early postoperative period on the prognosis of elderly patients undergoing esophagectomy. Methods We included 316 patients (age >= 65 years) who underwent esophagectomy. The skeletal muscle index (SMI) at the third lumber vertebra's bottom level was measured using computed tomography (CT) before surgery and 4 months after surgery. The SMI reduction rate, patient's prognosis, and recurrence rates were evaluated. Results The SMI reduction rates in tertiles were < 1.25% in the first tertile (t1, n = 105), between 1.25 and 9.13% in the second tertile (t2, n = 106), and > 9.13% in the third tertile (t3, n = 105). Both relapse-free survival (RFS) and overall survival (OS) in t3 were significantly worse than those in t1 and t2 (p < 0.001). Therefore, we defined t3 as the massive reduction (MR) group and t1 and t2 as the limited reduction (LR) group. By univariate analysis, both RFS and OS were significantly poorer in the MR group than in LR. By multivariate analysis, the massive skeletal muscle loss during the early postoperative period was an independent factor for both RFS and OS. Conclusions Early postoperative skeletal muscle loss predicts both recurrence and poor survival.