A systematic review on the role of fish oil for the treatment of cachexia in advanced cancer: an EPCRC cachexia guidelines project.

Abstract

The European Palliative Care Research Collaboration is developing clinical guidelines on cachexia in patients with advanced cancer. A systematic review on the use of fish oil/omega-3-fatty acids (n-3-FA)/eicosapentaenoic acids (EPA) in advanced cancer patients suffering from cancer cachexia was performed as part of the guideline development. The systematic literature search in Medline on the use of fish oil/n-3-FA/EPA identified 244 papers, with 38 publications included in the final evaluation. Some smaller trials, often unrandomized and without a control group, reported a good effect of n-3-FA in patients with advanced cancer and cachexia. However, the results of the larger randomized controlled trials could not support the positive results, as they mostly did not find a significant effect. Adverse effects such as abdominal discomfort, fish belching, fish aftertaste, nausea and diarrhoea were reported with a low incidence. No serious adverse effects were documented, but adverse effects often had an impact on quality of life. This often limited dose escalations or even led to discontinuation of n-3-FA. There is not enough evidence to support a net benefit of n-3-FA in cachexia in advanced cancer. On the other hand, adverse effects were infrequent, with no severe adverse effects. The results from the review led to a weak negative GRADE recommendation.