Early postoperative decrease of skeletal muscle mass predicts recurrence and poor survival after surgical resection for perihilar cholangiocarcinoma

BACKGROUND: Preoperative sarcopenia is a predictor of poor survival in cancer patients. We hypothesized that sarcopenia could progress as occult metastasis arose, especially after highly invasive surgery for highly aggressive malignancy. This study aimed to evaluate the associations of postoperative changes in skeletal muscle mass volume with survival outcomes in patients who underwent surgery for perihilar cholangiocarcinoma. METHODS: Fifty-six patients who underwent major hepatectomy with extrahepatic bile duct resection for perihilar cholangiocarcinoma were studied. The skeletal muscle index (SMI) at the third lumbar vertebra was calculated from axial computed tomography images taken preoperatively and 3–6 months postoperatively (early postoperative period). The associations of clinicopathological variables, including changes of SMI after surgery, with overall survival and recurrence-free survival were evaluated. Moreover, the associations of decreased SMI and elevated serum carbohydrate antigen 19–9 level with early recurrence and poor survival was compared. RESULTS: Among 56 patients, 26 (46%) had sarcopenia preoperatively and SMI decreased in 29 (52%) in the early postoperative period. During the median follow-up of 57.9 months, 35 patients (63%) developed recurrence and 29 (50%) died. Decreased SMI in the early postoperative period was independently associated with a shorter overall survival (hazard ratio, 2.39; 95% confidence interval, 1.00–6.18; P = 0.049) and a shorter recurrence-free survival (hazard ratio, 2.14; 95% confidence interval, 1.04–4.57; P = 0.039), whereas elevated carbohydrate antigen 19–9 level was not. CONCLUSIONS: Decreased SMI in the early postoperative period may be used as a predictor for recurrence and poor survival in patients undergoing surgery for perihilar cholangiocarcinoma.