Body composition-based nutritional status during neoadjuvant chemotherapy and its association with relative dose intensity and hematologic toxicity in patients with gastric cancer.

Objective: This study investigated changes in body composition before and after neoadjuvant therapy in patients with gastric cancer and explored the relationships between these changes, relative dose intensity (RDI), and hematological toxicity. Methods: Body composition parameters (muscle mass, skeletal muscle mass, body fat mass, visceral fat area, and water content) were measured via an InBody 720 analyzer before and after treatment. The primary outcome was a reduced RDI (<85%), and the secondary outcome was Grade 2 or 3 hematological toxicity. Results: Patients with a reduced RDI (<85%) presented significant decreases in muscle mass, skeletal muscle mass, and total body water content after therapy and had longer treatment duration. Greater muscle mass, skeletal muscle mass, and total body water content were associated with lower risks of reduced RDI [OR: 0.808 (0.697-0.938)], [OR: 0.699 (0.545-0.897)], and [OR: 0.759 (0.626-0.920)], respectively. Grade 2 thrombocytopenia was associated with reduced muscle mass and total body water, as well as increased body fat mass and visceral fat area. In further regression analyses, greater skeletal muscle mass was associated with a lower risk of grade 2 thrombocytopenia [OR: 0.657 (0.434-0.996)]. Conclusion: Higher muscle mass and total body water were associated with a lower risk of reduced RDI, whereas body fat mass showed no significant association. Regarding hematologic toxicity, grade 2 thrombocytopenia was associated with adverse changes in body composition, and greater skeletal muscle mass was associated with a lower risk in the adjusted analysis.