Immunonutrition vs Standard Nutrition for Cancer Patients: A Systematic Review and Meta‐Analysis (Part 1)

Background: This epidemiological observational study aimed at determining the prevalence of malnutrition in non-selected adults with cancer, to identify risk factors of malnutrition and correlate the results with length of stay and 2-month mortality. Methods: This prospective multicentre 1-day study conducted in 17 French Comprehensive Cancer Centres included 1545 patients. Body mass index (BMI), weight loss (WL) in the past 6 months and age were routinely recorded according to the French national recommendations for hospitalised patients; malnutrition was rated as absent, moderate or severe according to the level of WL and BMI. Age, sex, tumour site, type of hospitalisation and treatment, disease stage, World Health Organisation performance status (PS) and antibiotic therapy were the potential malnutrition risk factors tested. Follow-up at 2 months allowed to determine the correlation with length of stay and mortality. Results: Malnutrition was reported in 30.9% of patients, and was rated as severe in 12.2%. In multivariate analysis, only pre-existing obesity (BMI⩾30), PS ⩾2 and head-and-neck or upper digestive cancers were associated with increased risk of malnutrition. Antibiotics use was significantly higher in malnourished patients (35.5 vs 22.8% P<0.001). Severe malnutrition was independently associated with mortality. The median length of stay was 19.3±19.4 days for malnourished patients vs 13.3±19.4 days for others (P<0.0001). Conclusion: In French Comprehensive Cancer Centres, one out of three cancer patients are malnourished and this was associated with a longer length of stay. Pre-existing obesity could be identified as a new risk factor for malnutrition in our cancer patient population perhaps because of a misidentification or a delay in nutrition support in this category of patients.

Perioperative nutrition with specialized enteral diets improves outcome when compared with standard formulas. A post-hoc analysis suggested preoperative administration as the most important period. Thus, we designed a study to understand prospectively whether preoperative supplementation could be as efficacious as the perioperative approach and superior to a conventional treatment (no artificial nutrition) in reducing postoperative infections and length of hospital stay. A total of 305 patients with preoperative weight loss <10% and cancer of the gastrointestinal tract were randomized to receive the following: (1) oral supplementation for 5 days before surgery with 1 L/day of a formula enriched with arginine, omega-3 fatty acids, and RNA, with no nutritional support given after surgery (preoperative group, n = 102); (2) the same preoperative treatment plus postoperative jejunal infusion with the same enriched formula (perioperative group, n = 101); and (3) no artificial nutrition before and after surgery (conventional group; n = 102). The 3 groups were comparable for all baseline and surgical characteristics. Intention-to-treat analysis showed a 13.7% incidence of postoperative infections in the preoperative group, 15.8% in the perioperative group, and 30.4% in the conventional group (P = 0.006 vs. preoperative; P = 0.02 vs. perioperative). Length of hospital stay was 11.6 +/- 4.7 days in the preoperative group, 12.2 +/- 4.1 days in the perioperative group, and 14.0 +/- 7.7 days in the conventional group (P = 0.008 vs. preoperative and P = 0.03 vs. perioperative). Preoperative supplementation is as effective as perioperative administration in improving outcome. Both strategies seem superior to the conventional approach.

The immune system, including its inflammatory components, is fundamental to host defense against pathogenic invaders. It is a complex system involving interactions amongst many different cell types dispersed throughout the body. Central to its actions are phagocytosis, processing of antigens derived from intracellular and extracellular pathogens, activation of T cells with proliferation and production of cytokines that elicit effector cell functions such as antibody production and killing cell activity. Inappropriate immunologic activity, including inflammation, is a characteristic of many common human disorders. Eicosanoids produced from arachidonic acid have roles in inflammation and regulation of T and B lymphocyte functions. Eicosapentaenoic acid (EPA) also gives rise to eicosanoids and docosahexaenoic acid (DHA) to docosanoids; these may have differing properties to arachidonic acid-derived eicosanoids. EPA and DHA give rise to newly discovered resolvins. Human immune cells are typically rich in arachidonic acid, but arachidonic acid, EPA and DHA contents can be altered through oral administration of those fatty acids. This results in a change pattern of production of eicosanoids and probably also of docosanoids and resolvins, although the latter are not well examined in the human context. Changing the fatty acid composition of immune cells also affects phagocytosis, T-cell signaling and antigen presentation capability. These effects appear to mediated at the membrane level suggesting important roles of fatty acids in membrane order, lipid raft structure and function and membrane trafficking.