Longitudinal trajectories of nutritional markers in patients with de novo Stage IV gastric cancer: a descriptive analysis using one-year survival as a reference.

[PURPOSE] This study investigated patients whose initial diagnosis was de novo Stage IV gastric cancer, a population with extremely poor prognosis and limited evidence regarding how longitudinal nutritional changes evolve over time in advanced disease. We examined the trajectories of hemoglobin (Hgb), body mass index (BMI), and the prognostic nutritional index (PNI) as well as descriptively explored differences in nutritional trajectories between survival-defined groups based on one-year survival.

[METHODS] A retrospective longitudinal study was conducted among patients with pathologically confirmed de novo Stage IV gastric adenocarcinoma at a medical center in Taiwan (2015-2024). Nutritional markers were collected at baseline and at 1, 2, 3, 6, and 9 months. Patients were descriptively grouped according to one-year overall survival, which was used solely as a post hoc analytic reference for exploratory comparative analyses of longitudinal nutritional trajectories. Between-group differences were tested using the Mann-Whitney U test, and generalized estimating equations were applied to evaluate group, time, and group × time effects.

[RESULTS] Among 131 patients, 36 survived at the one-year timepoint (27.5%). Baseline demographics and tumor characteristics did not differ between survival-defined groups. Non-survivors consistently had lower Hgb (baseline-6 months: all p < .001; 9 months: p = .026). BMI showed no baseline differences; however, significant group × time interactions emerged at 6 and 9 months. PNI was significantly lower in non-survivors at every time point (all p < .001) and showed significant interactions at 3, 6, and 9 months, reflecting a more pronounced longitudinal decline.

[CONCLUSION] In de novo Stage IV gastric cancer, differences in PNI and Hgb were evident between survival-defined groups from diagnosis onward, whereas BMI reflected nutritional deterioration only at later stages. Longitudinal changes in PNI observed to parallel evolving nutritional and systemic vulnerability. These findings are descriptive and hypothesis-generating rather than predictive. Dynamic nutritional assessment may contribute to understanding patient trajectories in patients with advanced gastric cancer.