Effects of an Oral Elemental Nutritional Supplement on Post-gastrectomy Body Weight Loss in Gastric Cancer Patients: A Randomized Controlled Clinical Trial

Post-gastrectomy weight loss is associated with deterioration in quality of life, and influences the long-term prognosis of gastric cancer patients. We conducted a prospective, randomized controlled, open-label study to examine whether an oral elemental diet (Elental(A (R)), Ajinomoto Pharmaceuticals, Tokyo, Japan; hereafter referred to as ED) prevents postoperative weight loss in post-gastrectomy patients. Patients were randomly divided to receive the ED or control diet. The ED group received 300 kcal of ED plus their regular diet for 6-8 weeks after surgery, starting from the day the patient started a soft rice or equivalent diet after surgery, while the control group received the regular diet alone. The primary endpoint was the percentage of body weight loss (%BWL) from the presurgical body weight to that at 6-8 weeks after surgery. Secondary endpoints were dietary adherence, nutrition-related blood parameters, and adverse events. This study included 112 patients in eight hospitals. The mean treatment compliance rate in the ED group was 68.7 +/- 30.4 % (median 81.2 %). The %BWL was significantly different between the ED and control groups (4.86 +/- 3.72 vs. 6.60 +/- 4.90 %, respectively; p = 0.047). In patients who underwent total gastrectomy, the %BWL was significantly different between the two groups (5.03 +/- 3.65 vs. 9.13 +/- 5.43 %, respectively; p = 0.012). In multivariate analysis, ED treatment, surgery type, and preoperative performance status were independently associated with %BWL. No significant differences were observed in the other clinical variables. ED supplementation reduced postoperative weight loss in gastric cancer patients undergoing gastrectomy.