Association between pre-treatment malnutrition and chemotherapy toxicity in patients with advanced or metastatic gastroenteric tumors receiving systemic therapy

Background Malnutrition is prevalent in individuals with gastroenteric malignancies and may negatively influence chemotherapy tolerance. This investigation evaluated the relationships between pre-treatment nutritional status and chemotherapy-derived toxicity utilizing anthropometric, biochemical, and composite nutritional indices. Methods A retrospective analysis was conducted involving 720 individuals with histologically verified advanced or metastatic gastroenteric malignancies, including 360 gastric cancer cases and 360 colorectal cancer cases, who were given systemic cytotoxic chemotherapy between 2017 and 2023. Baseline nutritional status was examined via body mass index (BMI), serum albumin, Prognostic Nutritional Index (PNI), and Nutritional Risk Index (NRI). Chemotherapy-associated toxicities were graded based on the CTCAE criteria. Multivariable logistic regression models were built individually by cancer type and toxicity category. Results Hematological toxicity was reported in 49.7% of gastric cancer and 63.1% of colorectal cancer subjects, while non-hematological toxicity occurred in 38.1 and 56.1%, respectively. In gastric cancer, underweight status significantly elevated the possibility of hematological toxicity (OR 1.97, 95% CI 1.06–3.64; p = 0.03), as did hypoalbuminemia (OR 1.71, 95% CI 1.11–2.62; p = 0.01) and PNI ≤ 45 (OR 1.70, 95% CI 1.11–2.61; p = 0.01). Age was independently linked with non-hematological damage (OR 1.03 per year, 95% CI 1.01–1.06; p = 0.001). In colorectal cancer, age individually indicated both hematological (OR 1.03 per year; p = 0.001) and non-hematological harm (OR 1.04 per year; p = 0.001). Lower BMI (OR 2.00, 95% CI 1.02–3.91; p = 0.04), hypoalbuminemia (OR 1.85, 95% CI 1.12–3.04; p = 0.01), PNI ≤ 45 (OR 1.90, 95% CI 1.21–2.97; p = 0.005), and NRI ≤ 83 (OR 2.50, 95% CI 1.29–4.85; p = 0.007) individually determined hematological injury, while hypoalbuminemia (OR 1.90; p = 0.01) and NRI ≤ 83 (OR 2.35; p = 0.01) were also linked with non-hematological damage. Conclusion Pre-treatment nutritional inadequacy was connected with chemotherapy toxicity, which supports periodic nutritional screening prior to medication.