Assessment of sarcopenia in patients with upper gastrointestinal tumors: Prevalence and agreement between computed tomography and dual-energy x-ray absorptiometry.

Abstract

BACKGROUND & AIMS\nSarcopenia is associated with an increased risk of complications to treatment and lower survival rates in patients with cancer, but there is a lack of agreement on cut-off values and assessment methods. We aimed to investigate the prevalence of sarcopenia assessed by dual-energy x-ray absorptiometry (DXA) and computed tomography (CT) as well as the agreement between the methods for identification of sarcopenia.\n\n\nMETHODS\nThis cross-sectional study pooled data from two studies including patients scheduled for surgery for gastrointestinal tumors. We assessed sarcopenia using two different cut-off values derived from healthy young adults for DXA and two for CT. Additionally, we used one of the most widely applied cut-off values for CT assessed sarcopenia derived from obese cancer patients. The agreement between DXA and CT was evaluated using Cohen s kappa. The mean difference and range of agreement between DXA and CT for estimating total and appendicular lean soft tissue were assessed using Bland-Altman plots.\n\n\nRESULTS\nIn total, 131 patients were included. With DXA the prevalence of sarcopenia was 11.5% and 19.1%. Using CT, the prevalence of sarcopenia was 3.8% and 26.7% using cut-off values from healthy young adults and 64.1% using the widely applied cut-off value. The agreement between DXA and CT in identifying sarcopenia was poor, with Cohen s kappa values ranging from 0.05 to 0.39. The mean difference for estimated total lean soft tissue was 1.4\xa0kg, with 95% limits of agreement from\xa0-8.6 to 11.5\xa0kg. For appendicular lean soft tissue, the ratio between DXA and CT was 1.15, with 95% limits of agreement from 0.92 to 1.44.\n\n\nCONCLUSIONS\nThe prevalence of sarcopenia defined using DXA and CT varied substantially, and the agreement between the two modalities is poor.