Meta-analysis of preoperative oral nutritional supplements for patients with gastric cancer: East Asian experience.

Whether it is beneficial to give preoperative oral nutritional supplements (P-ONS) to gastric cancer (GC) patients is still inconclusive. This study aimed to systematically explore the effectiveness and safety of P-ONS in GC patients. The PubMed, EMBASE, Medline, Cochrane Library, Chinese Biomedicine Literature Database (SinoMed), Chinese Scientific Journal Database (VIP), Chinese National Knowledge Infrastructure (CNKI) and Wanfang databases were searched to identify relevant literature. A total of 11 randomized controlled trials (1183 patients) were included. Meta-analysis showed significantly lower levels of white blood cells (MD, -0.65; 95% CI, -1.01 to -0.30; P = 0.0003) and C-reactive protein (MD, -0.24; 95% CI, -0.31 to -0.16; P < 0.00001) in the P-ONS group than those in the routine diet group. Compared with the routine diet group, the P-ONS group had higher levels of albumin (MD, 1.63; 95% CI, 0.40-2.87; P = 0.010), IgG (MD, 0.65; 95% CI, 0.44-0.86; P < 0.00001), IgA (MD, 0.20; 95% CI, 0.02-0.37; P = 0.03), CD4 (MD, 2.02; 95% CI, 0.82-3.22; P = 0.001) and CD4/CD8 (MD, 0.07; 95% CI, 0.02-0.12; P = 0.008). However, there were no significant differences (P > 0.05) in terms of prealbumin (P = 0.08), IgM (P = 0.25), postoperative complications (P = 0.18), and body weight (P = 0.25) between the two groups. For gastric cancer patients with nutritional risk, preoperative oral nutritional supplements for 5-7 days may effectively reduce the postoperative inflammatory response, enhance immune function and improve the nutritional status of patients.