Oral nutritional supplements for gastric cancer – the review of current evidence

Abstract
The analysis of the current evidence base concerning the use of oral nutritional supplements (ONS) in gastric cancer (GC) has been made. Databases of scientific information eLIBRARY.ru and PubMed were used. Emphasis is placed on randomized clinical trials and meta‑analyses. The application of ONS is suggested for all patients who undergo to surgical treatment for GC. Its use allows increasing protein and energy consumption, improving the quality of life, some parameters of nutritional status and immunity (albumin, blood lymphocytes etc.). In patients with severe malnutrition (SM) ONS can significantly reduce the incidence of clinically important postoperative complications. The use of this type of medical nutrition in the first 5 days after surgery is safe and does not increase the rate of anastomotic leak. After gastrectomy (GE) its administration reduces the time of recovery of bowel motor function and the duration of hospitalization. After distal GE delay of gastric emptying may occur. In patients with SM, early start of enteral nutrition should be considered. After discharge from the hospital ONS can decelerate the progression of malnutrition, improve the tolerance of adjuvant chemotherapy and improve the quality of life. These effects are most clear after GE and in patients with a high risk of malnutrition (NRS‑2002 ≥ 3). There are no evident advantages of any particular type of ONS in patients with GC. When choosing a specific product, preference should be given to formulas with optimal nitrogen: non‑protein kilocalories ratio, osmolarity closest to physiological and individually selected organoleptic properties. It is recommended that the patient consume at least 200–250 ml of the mixture per day, and in the early postoperative period focus have to be made not on the target volume, but on signs of tolerability.