Abstract
BACKGROUND: The objective of this study is to investigate the potential association between change in body composition before and after cetuximab-based therapy and the prognostic outcomes among individuals diagnosed with advanced colorectal cancer. METHODS: A retrospective analysis was undertaken on a cohort of 81 patients diagnosed with RAS wild-type (WT) metastatic colorectal cancer (mCRC) who were treated with cetuximab-based first-line therapy. To assess relevant body composition parameters, quantitative computed tomography (QCT) scans were conducted both before and after cetuximab treatment. These parameters encompassed measurements of visceral fat area (VFA), subcutaneous fat area (SFA), total muscle area (TMA) at the third lumbar vertebra level (L3), and bone mineral density (BMD) at the first and second vertebrae levels (L1/2). The skeletal muscle index (SMI) was subsequently calculated, and changes in parameters (∆VFA, ∆SFA, ∆SMI, ∆BMD) were standardized. RESULTS: The cut-off values for ∆VFA, ∆SFA, ∆SMI, and ∆BMD were 0.28%, -2.76%, -2.97%, and -7.98%, respectively. CEA, ∆VFA, ∆SMI, and ∆BMD were associated with poor outcomes of cetuximab-based first-line chemotherapy (P < 0.05). The risk of disease progression was higher when ∆VFA < 0.28%, ∆SFA < -2.76%, ∆SMI < -2.97%, and ∆BMD < -7.98%. Multivariate analysis indicated that CEA (HR: 0.396, 95% CI: 0.160-0.980, P = 0.045), ∆VFA (HR: 0.307, 95% CI: 0.145-0.651, P = 0.002), and∆SMI (HR: 0.725, 95% CI: 0.322-1.630, P = 0.001) have significant prognostic value for progression-free survival (PFS) in RAS WT mCRC patients treated with cetuximab-based first-line chemotherapy. CONCLUSIONS: CEA, ∆VFA, and ∆SMI are independent predictors for PFS in patients with advanced colorectal cancer. High levels of CEA, ∆VFA, and low levels of ∆SMI may indicate poorer outcomes. CEA, ∆VFA, and ∆SMI can be used to predict PFS in mCRC patients receiving cetuximab-based first-line chemotherapy. TRIAL REGISTRATION: This study was approved by the Ethics Committee of Anhui Provincial Cancer Hospital of Anhui Medical University (Batch No:2024-ZNY-02). All subjects signed an informed consent form.