BACKGROUND Weight loss during chemotherapy is a significant prognostic factor for poor survival in patients with advanced gastric cancer (AGC). However, in most studies, weight loss was measured at the end of chemotherapy, limiting its clinical use. In this study, we evaluated whether weight loss during the first month of chemotherapy could predict survival outcomes in patients with AGC.

METHODS We analyzed 719 patients with metastatic or recurrent AGC who were receiving palliative chemotherapy. We calculated the initial body mass index (BMIi), percent weight loss after 1 month of chemotherapy (ΔW 1m), percent weight loss after last administration of chemotherapy (ΔW end), and average weight loss per month during chemotherapy (ΔW/m). We correlated these data with overall survival (OS) by receiver-operating characteristic (ROC) curves and Kaplan-Meier curves, and performed a subgroup analysis using Cox regression.

RESULTS The probabilities of longer OS had stronger correlations with ΔW/m and ΔW 1m than with ΔW end or BMIi. A significant positive correlation between ΔW 1m and ΔW/m (r (2) = 0.591, p < 0.001) was observed. Median OS of patients with ΔW 1m more than 3 % was significantly shorter than in patients with less weight loss (OS: 9.7 vs. 16.3 months, p < 0.001). Subgroup analysis revealed that ΔW 1m accompanied poor survival irrespective of other clinical characteristics.

CONCLUSION Weight loss at the very first month of palliative chemotherapy could predict unfavorable survival outcomes in AGC.