Background & aims: Sarcopenia is a commonly prevalent malnutrition condition and serves as a valuable adverse prognostic indicator for survival in patients with cancer. A rapid and convenient screening test for sarcopenia would be helpful for patients. Aim of the study was to evaluate the diagnostic value of SARC-F and SARC-F combined with calf circumference (SARC-CaIF) for screening cancer-related sarcopenia in cancer population. Methods: A total of 309 patients with cancer who had routine abdominal comptued tomography (CT) images within 30 days were enrolled in this cross-sectional cohort. Sarcopenia was determined as the presence of both low muscle mass (LMM) and low muscle strength; muscle mass was evaluated by CT-scan, and muscle strength was evaluated by handgrip strength (HGS). Two different diagnostic criteria (Western criteria and Eastern criteria) were used as the reference standards. The sensitivity and specificity analyses of the SARC-F and SARC-CalF were calculated. The receiver operating characteristic (ROC) curves and the area under the ROC curves (AUC) were used to compare the diagnostic value of SARC-F and SARC-CalF for sarcopenia. Results: The prevalence of LMM and sarcopenia in the patient group was 85.1% and 50.5% by Western criteria. Corresponding figures were lower as 42.4% and 26.2% by Eastern criteria. In the overall study population, when sarcopenia defined by the Eastern criteria, sensitivity and specificity of SARC-CalF were 66.6% and 70.1%, whereas that of SARC-F were 32.1% and 90.7%, respectively. The AUCs for SARC-CalF and SARC-F were 0.75 (95% confidence interval (CI) 0.70-0.80) and 0.70 (95% CI 0.64-0.75), respectively (P = 0.003). Against the Western criteria, SARC-CalF also had better sensitivity (55.1% vs. 22.4%) but lower specificity (76.4% vs. 92.1%) than that of SARC-F. The AUCs of SARC-CalF and SARC-F were 0.70 (95% CI 0.65-0.75) and 0.68 (95% CI 0.62-0.73), respectively, but the difference was not significant (P = 0.211). Conclusions: SARC-CalF significantly increases the sensitivity and overall diagnostic accuracy of SARC-F for screening sarcopenia. SARC-CalF can be a rapid screening tool for sarcopenia in patients with cancer. (C) 2020 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.