Parenteral nutrition with n-3 PUFA in patients with gastrointestinal cancer
Most patients with gastrointestinal (GI) cancer suffer varying degrees of malnutrition and deterioration to their immune function. This not only affects healing of the anastomotic stoma, but also worsens the patient’s prognosis, increasing the risk of secondary post-surgical infections and other complications. Deterioration to immune function play an important role in recurrence and metastasis, as it can accelerate diffusion of tumour cells. Therefore improving nutritional status and immune function is of major clinical importance among these patients.
In parenteral nutrition, lipid emulsions are important dietary supplements, as they provide the essential fatty acids needed to obtain energy and maintain cell structure and adipose tissue. Evidence shows that omega-3 polyunsaturated fatty acids (n-3 PUFA) play a key role in the cell membrane, can regulate immune function, modulate inflammatory response, reduce infectious complications and inhibit tumour growth. Results from a number of studies on GI cancer surgery patients investigating the efficacy of parenteral nutrition with n-3 PUFA indicate that they could be useful in preventing post-surgical infectious complications, but the heterogeneity of their designs, limited sample sizes and possible bias make their conclusions unreliable.
Therefore a group of researchers from the Department of Pancreatic and Gastric Surgery at the National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Beijing Union Medical College conducted a meta-analysis of all relevant controlled, randomised trials on the subject. This meta-analysis confirms that early parenteral nutrition including n-3 PUFA in GI cancer not only improves post-surgical markers for immune function, reduces the inflammatory response and improves healing, but also improves immune deterioration induced by conventional parenteral nutrition and the tumour. These conclusions support the inclusion of n-3 PUFA in parenteral nutrition for patients with GI cancer.