Diagnostic Performance of Four Screening Tools for Detecting Low Muscle Mass and Sarcopenia in Preoperative Older Japanese Patients with Colorectal Cancer According to the AWGS 2019 Criteria

IntroductionColorectal cancer (CRC) is the third most commonly diagnosed cancer worldwide, with an estimated 1.9 million new cases and 903,859 deaths reported in 2022 1 .Surgical resection remains the cornerstone of curative treatment for CRC.Despite advances in surgical techniques, including minimally invasive surgery, approximately 20% of patients experience postoperative complications 2 .These complications are typically associated with prolonged hospital stay, increased healthcare costs, and decreased long-term survival 3-5 .Sarcopenia, characterized by the loss of skeletal muscle mass and decline in muscle strength Abstract Objectives: Sarcopenia and low muscle mass are distinct clinical conditions associated with adverse outcomes after colorectal cancer (CRC) surgery.Due to limited effective screening methods, we evaluated the diagnostic performance of four tools for these conditions in preoperative patients with CRC.Methods: This cross-sectional study included patients aged ≥65 years with stage I-III CRC scheduled for elective surgery.Sarcopenia and low appendicular skeletal muscle mass (ASM) were diagnosed according to the Asian Working Group for Sarcopenia 2019 criteria.Diagnostic performance of calf circumference (CC), SARC-F, SARC-CalF, and the Ishii score was evaluated.Results: Ninety-eight patients (48.0%females, mean age 77.4 ± 6.2 years) were included.Prevalences of low ASM and sarcopenia were 56.1% and 41.8%, respectively.For low ASM, CC demonstrated the highest accuracy (AUC 0.907, sensitivity 80.0%, specificity 86.0%), significantly outperforming SARC-F and SARC-CalF (AUCs 0.617 and 0.854; p