International guidelines on the nutritional management of patients with cancer recommend intervention with dietary advice and/or oral nutritional supplements in patients who are malnourished or those judged to be at nutritional risk, but the evidence base for these recommendations is lacking. We examined the effect of oral nutritional interventions in this population on nutritional and clinical outcomes and quality of life (QOL).
Electronic searches of several databases including MEDLINE, EMBASE, and CINAHL (from the first record to February 2010) were searched to identify randomized controlled trials of patients with cancer who were malnourished or considered to be at risk of malnutrition and receiving oral nutritional support compared with routine care. We performed a meta-analysis using a fixed effect model, or random effects models when statistically significant heterogeneity was present, to calculate relative risk (mortality) or mean difference (weight, energy intake, and QOL) with 95% confidence intervals (CIs). Heterogeneity was determined by using the χ(2) test and the I(2) statistic. All statistical tests were two-sided.
Thirteen studies were identified and included 1414 participants. The quality of the studies varied, and there was considerable clinical and statistical heterogeneity. Nutritional intervention was associated with statistically significant improvements in weight and energy intake compared with routine care (mean difference in weight = 1.86 kg, 95% CI = 0.25 to 3.47, P = .02; and mean difference in energy intake = 432 kcal/d, 95% CI = 172 to 693, P = .001). However, after removing the main sources of heterogeneity, there was no statistically significant difference in weight gain or energy intake. Nutritional intervention had a beneficial effect on some aspects of QOL (emotional functioning, dyspnea, loss of appetite, and global QOL) but had no effect on mortality (relative risk = 1.06, 95% CI = 0.92 to 1.22, P = .43; I(2) = 0%; P(heterogeneity) = .56).
Oral nutritional interventions are effective at increasing nutritional intake and improving some aspects of QOL in patients with cancer who are malnourished or are at nutritional risk but do not appear to improve mortality.