Role of Baseline Computed-Tomography-Evaluated Body Composition in Predicting Outcome and Toxicity from First-Line Therapy in Advanced Gastric Cancer Patients

Sarcopenia is recognised as a predictor of toxicity and survival in localised and locally advanced gastric cancer (GC). Its prognostication power in advanced unresectable or metastatic GC (aGC) is debated. The survival impact of visceral and subcutaneous fat distribution (visceral fat area (VFA)/subcutaneous fat area (SFA)) is ambiguous. Our aim was to determine the influence of body composition parameters (BCp) on toxicity and survival in aGC patients undergoing palliative treatment. BCp were retrospectively assessed by baseline computed tomography for 78 aGC patients who received first-line chemotherapy from March 2010 to January 2017. Correlations between BCp and toxicity and survival were calculated by χ2-test and by log-rank-test and Cox-model, respectively. Sarcopenia fails to show association with progression-free survival (PFS) (p = 0.44) and overall survival (OS) (p = 0.88). However, sarcopenia influences the development of high-grade neutropenia (p = 0.048) and mucositis (p = 0.054). VFA/SFA (high vs. all the rest) results as a strong predictor of objective response (p = 0.02) and outcome (PFS, p = 0.001; OS, p = 0.02). At multivariate analysis for PFS, prognostic factors are VFA/SFA (p = 0.03) and a neutrophil–lymphocyte ratio >3. The same factors remain significant for OS (each p = 0.03) along with Eastern Cooperative Oncology Group (ECOG) performance status (p = 0.008) and number of metastatic sites ≥2 (p < 0.001). In our cohort of aGC, VFA/SFA exhibit a robust impact on survival, with a higher sensitivity than sarcopenia.