Metabolic response to feeding in weight-losing pancreatic cancer patients and its modulation by a fish-oil-enriched nutritional supplement

Weight-losing patients with advanced cancer often fail to gain weight with conventional nutritional support. This suboptimal response might be explain ed, in part, by an increased metabolic response to feeding. It has been sug gested that eicosapentaenoic acid (EPA) can modify beneficially the metabol ic response to cancer. The aim of the present study was to examine the meta bolic response to feeding in cancer and the effects of an EPA-enriched oral food supplement on this response. A total of 16 weight-losing, non-diabeti c patients with un resectable pancreatic adenocarcinoma and six healthy, we ight-stable controls were studied by indirect calorimetry in the fasting an d fed states. Body composition was estimated by bioimpedence analysis. Canc er patients were then given a fish-oil-enriched nutritional supplement prov iding 2 g of EPA and 2550 kJ daily, and underwent repeat metabolic study af ter 3 weeks of such supplementation. At baseline, resting energy expenditur e whether expressed per kg body weight, lean body mass or body cell mass wa s significantly greater in the cancer patients compared with controls. Fat oxidation was significantly higher in the fasting state in cancer patients [median 1.26 g.kg(-1).min(-1) (interquartile range 0.95-1.38)] than in cont rols [0.76 g.kg(-1).min(-1) (0.62-0.92); P < 0.05]. Over the 4 h feeding pe riod, changes in insulin and glucose concentrations in cancer patients sugg ested relative glucose intolerance. In response to oral meal feeding, the p ercentage change in the area under the curve of energy expenditure was sign ificantly lower in the cancer patients [median 7.9% (interquartile range 3. 4-9.0)] than in controls [12.6% (9.9-15.1); P < 0.01]. After 3 weeks of the EPA-enriched supplement, the body weight of the cancer patients had increa sed and the energy expenditure in response to feeding had risen significant ly [9.6% (6.3-12.4)], such that it was no different from baseline healthy c ontrol values. Similarly, fasting fat oxidation fell to 1.02 g.kg(-1).min(- 1) (0.8-1.18), again no longer significantly different from baseline health y control values. While weight-losing patients with advanced pancreatic can cer have an increased resting energy expenditure and increased fat oxidatio n, the energy cost of feeding is, in fact, reduced. Provision of a fish-oil -enriched nutritional supplement results in some normalization of the metab olic response in both the fasted and fed states, in association with an imp rovement in nutritional status.