Clinical Utility of the Preoperative Cachexia Index in Patients Undergoing Curative Gastrectomy for Gastric Cancer

Cancer cachexia, a multifactorial metabolic syndrome characterized by irreversible skeletal muscle wasting and functional decline, begins early in cancer progression. As cachexia development is closely associated with deteriorating quality of life and reduced survival, early detection and identification of predictive biomarkers are crucial for improving patient outcomes. Recently, the Cachexia Index (CXI), which incorporates skeletal muscle mass, nutritional status, and inflammation, has been proposed. In this study, we aimed to evaluate the clinical significance of preoperative CXI in patients with gastric cancer (GC).

In total, 459 patients who underwent curative gastrectomy for GC at the Kanagawa Cancer Center between December 2013 and November 2017 were included. Preoperative CXI was calculated using skeletal muscle area at the third lumbar vertebra (L3) on computed tomography, serum albumin concentration, and neutrophil-to-lymphocyte ratio. Patients were categorized into high and low CXI groups based on appropriate cutoff values. Associations between preoperative CXI and clinicopathological characteristics were examined. Overall survival (OS) and recurrence-free survival (RFS) were analyzed using propensity score matching.

Low CXI was significantly associated with older age, poorly differentiated tumors, and a higher rate of total gastrectomy. Survival analysis demonstrated significantly lower OS and RFS in the low CXI group (86.1% vs. 92.9%, p=0.01; and 83.1% vs. 91.1%, p=0.01, respectively). Multivariate analysis identified low CXI as an independent prognostic factor for OS (HR=2.44; 95% CI=1.25-4.76; p=0.01) and RFS (HR=2.22; 95% CI=1.19-4.17; p=0.01).

Preoperative CXI may serve as a valuable prognostic biomarker in patients undergoing curative gastrectomy for GC.