Evaluation of Regional Body Circumferences and Serum Albumin for Identifying Nutritional Risk in Gastric Adenocarcinoma

Background and Objectives: We evaluated the association of regional body circumferences, body mass index (BMI), and serum albumin with concurrent nutritional risk in gastric adenocarcinoma. Materials and Methods: This single-center retrospective cross-sectional study included patients assessed between January 2024 and January 2026. Nutritional risk was defined as a Nutritional Risk Screening 2002 (NRS-2002) score ≥ 3. Receiver operating characteristic analysis assessed discrimination of this screening outcome. Logistic models incorporating arm circumference alone or with albumin were evaluated in the same complete-case sample using 1000 bootstrap resamples for internal validation. Results: Among 102 patients, 100 had NRS-2002 scores and 20 (20.0%) had nutritional risk. In 95 complete cases, including 19 patients at risk, areas under the curve (AUCs) were 0.869 for arm circumference, 0.864 for BMI, and 0.858 for albumin. In the combined model, each 1-cm decrease in arm circumference and each 0.1-g/dL decrease in albumin were associated with higher odds of nutritional risk: mutually adjusted odds ratios were 1.67 (95% confidence interval [CI], 1.22–2.29) and 1.27 (95% CI, 1.08–1.51), respectively. Adding albumin improved model fit (p = 0.001). Exploratory, internally validated optimism-corrected AUCs were 0.926 for the combined model and 0.873 for arm circumference alone. Conclusions: Arm circumference and albumin were associated with NRS-2002-defined nutritional risk. The small number of outcome events, incomplete covariate information, and absence of external validation limit interpretation. These findings do not establish a diagnosis of malnutrition, improvement in screening, or clinical utility.