Abdominal Visceral-to-Subcutaneous Fat Volume Ratio Predicts Survival and Response to First-Line Palliative Chemotherapy in Patients with Advanced Gastric Cancer

SIMPLE SUMMARY: This study was undertaken to address a crucial issue in the treatment of advanced gastric cancer (aGC). The prognosis for aGC patients is typically poor, with various factors affecting survival, such as disease stage and performance status. However, the impact of body composition, particularly abdominal fat distribution, on aGC patient outcomes remains debated. This research aimed to determine the significance of specific body composition parameters (BCPs), including visceral and subcutaneous fat volumes and the visceral-to-subcutaneous (VF/SF) fat volume ratio, in predicting overall survival (OS) and progression-free survival (PFS) in aGC patients treated with first-line palliative chemotherapy. The findings suggest that the VF/SF volume ratio, as measured by radiological methods, is a robust and independent predictor of survival and chemotherapy response in aGC. This research provides valuable insights into tailoring treatment strategies for aGC patients, potentially impacting clinical decisions and enhancing patient outcomes in the broader medical community. ABSTRACT: Prognosis in advanced gastric cancer (aGC) is predicted by clinical factors, such as stage, performance status, metastasis location, and the neutrophil-to-lymphocyte ratio. However, the role of body composition and sarcopenia in aGC survival remains debated. This study aimed to evaluate how abdominal visceral and subcutaneous fat volumes, psoas muscle volume, and the visceral-to-subcutaneous (VF/SF) volume ratio impact overall survival (OS) and progression-free survival (PFS) in aGC patients receiving first-line palliative chemotherapy. We retrospectively examined CT scans of 65 aGC patients, quantifying body composition parameters (BCPs) in 2D and 3D. Normalized 3D BCP volumes were determined, and the VF/SF ratio was computed. Survival outcomes were analyzed using the Cox Proportional Hazard model between the upper and lower halves of the distribution. Additionally, response to first-line chemotherapy was compared using the χ(2) test. Patients with a higher VF/SF ratio (N = 33) exhibited significantly poorer OS (p = 0.02) and PFS (p < 0.005) and had a less favorable response to first-line chemotherapy (p = 0.033), with a lower Disease Control Rate (p = 0.016). Notably, absolute BCP measures and sarcopenia did not predict survival. In conclusion, radiologically assessed VF/SF volume ratio emerged as a robust and independent predictor of both survival and treatment response in aGC patients.