Impact of Skeletal Muscle Mass, Muscle Quality, and Visceral Adiposity on Outcomes Following Resection of Intrahepatic Cholangiocarcinoma

Background. Decrease in skeletal muscle mass and function, known as sarcopenia, is associated with poor prognosis. Visceral fat accumulation also is related to mortality. This study investigated the impact of preoperative skeletal muscle mass, muscle quality, and visceral adiposity on outcomes in patients undergoing resection of intrahepatic cholangiocarcinoma (ICC). Methods. A retrospective analysis was performed of 109 patients undergoing resections of ICC between January 2004 and April 2015. Skeletal muscle mass [skeletal muscle index (SMI)], skeletal muscle quality [muscle attenuation (MA)], and visceral adiposity [visceral to subcutaneous adipose tissue area ratio (VSR)] were measured on preoperative computed tomography images. The impacts of these parameters on outcomes after ICC resections were analyzed. Results. The overall survival rates were significantly lower in patients with low SMI (P = 0.002), low MA (P = 0.032), and high VSR (P = 0.026) compared with patients with high SMI, high MA, and low VSR, respectively. With multivariate analyses, in patients with stage I-III, low SMI (hazard ratio (HR) 3.29, P = 0.003) and low MA (HR 2.86, P = 0.010) were revealed as independent significant risk factors for mortality. In patients with stage IV, none of these parameters was identified as risk factors, with only the absence of adjuvant chemotherapy identified as an independent risk factor for mortality (HR 5.92, P = 0.001). Conclusions. Although stage was the most important factor, low skeletal muscle mass and quality were closely related to mortality after resection of ICC in patients with stage I-III.