The association between radiographic osteosarcopenia and overall mortality among older patients undergoing colorectal...

BACKGROUND: Osteosarcopenia based on computed tomography (CT) is gaining attention as a predictor of adverse outcomes in older adults with cancer. AIMS: We examined whether preoperative radiographic osteosarcopenia was associated with overall mortality (OM) among older patients with colorectal cancer (CRC). METHODS: Data of older patients (aged ≥ 60 years) who had undergone CRC surgery between October 2018 and February 2024 were retrospectively analyzed. A preoperative abdominal CT scan was used to assess skeletal muscle index (SMI) (cm2/m2) and vertebral bone density (VBD) in Hounsfield units. Patients were assigned into the following categories according to their VBD and SMI status: (i) normal VBD and SMI; (ii) low VBD only; (iii) low SMI only; or (iv) radiographic osteosarcopenia defined as the combination of low VBD and low SMI. The associations between radiographic osteosarcopenia and overall mortality were examined using survival analysis. RESULTS: In total, 235 older patients (mean age: 71.8 years) were included in the analysis. Of the 235 patients, 90 (38.3%) had normal VBD and SMI, 28 (11.9%) had low VBD alone, 75 (31.9%) had low SMI alone, and 42 (17.9%) had radiographic osteosarcopenia based on low VBD and low SMI. In multivariable analysis, radiographic osteosarcopenia was associated with a significantly higher risk of OM (hazard ratio (HR): 3.43, 95%CI: 1.42–8.23, p = 0.006) compared to normal VBD and SMI status. Low VBD alone or low SMI alone were not significantly associated with OM. CONCLUSIONS: Radiographic osteosarcopenia is significantly associated with OM in older patients undergoing CRC surgery.