Refeeding Syndrome in Patients with Upper Gastrointestinal Cancer: A Retrospective Analysis of Nutritional and Biochemical Outcomes

Abstract

Background and Objective: Refeeding syndrome (RFS) is a potentially life-threatening metabolic complication that can develop following the reintroduction of nutrition in malnourished patients. It is characterized by shifts in fluid and electrolyte balance, particularly involving phosphorus, potassium and magnesium. Patients with upper gastrointestinal (GI) cancers may be particularly vulnerable to RFS because of inadequate nutritional intake, gastrointestinal obstruction, cancer-related cachexia and treatment-associated complications. This study was designed to evaluate changes in anthropometric and biochemical parameters associated with nutritional repletion in patients with upper GI cancer undergoing postoperative nutritional support between January 2022 and January 2025. Materials and Methods: This retrospective observational study was conducted at Shaukat Khanum Memorial Cancer Hospital and Research Center, Peshawar and included 97 adults with upper GI cancer who underwent surgery and received postoperative enteral or parenteral nutritional support. Weight, BMI and serum concentrations of sodium, potassium, magnesium and phosphorus were assessed before and after nutritional repletion. Paired t-tests were used to evaluate pre- and post-repletion changes, while Pearson correlation analysis was performed to assess relationships between pre- and post-repletion values. Results: Following nutritional repletion, significant decreases were observed in weight (−2.77 kg, p<0.001), BMI (-1.21 kg/m², p<0.001), serum potassium (-0.19 mmol/L, p<0.05) and phosphorus (-0.51 mmol/L, p<0.001). Serum sodium and magnesium levels remained stable. Strong positive correlations were observed between pre- and post-repletion measurements for weight (r = 0.95, p<0.001) and BMI (r = 0.96, p<0.001), while a moderate positive correlation was observed for phosphorus (r = 0.55, p<0.001). Conclusion: Patients with upper GI cancer demonstrated significant anthropometric and biochemical changes following nutritional repletion, particularly reductions in body weight, BMI, serum potassium and phosphorus concentrations. These findings highlight the importance of careful assessment of refeeding risk, gradual advancement of nutritional support and close monitoring of electrolyte levels in this vulnerable population.