Effect of EPA on Aerobic Performance, Muscle, and Quality of Life in Colorectal Cancer Surgery Patients (EPA-colo)

• Nutritional supplementation with 960mg EPA three times a day positively affects muscle function and mass [ Time Frame: Baseline and 6 weeks post-op ] [ Designated as safety issue: No ]
  Muscle function and mass will be assessed by muscle biopsies, assays of cellular aerobic function and DEXA scan and inflammation (measuring cellular markers of inflammation).
  
  

• The secondary aim is to look at the aerobic performance. [ Time Frame: Baseline and 5 weeks post-op. ] [ Designated as safety issue: No ]
  The secondary aim is to look at the aerobic performance assessed by cardiopulmonary exercise testing (CPEX) and perioperative outcome in patients with colorectal cancer post surgical resection.
  
  

Cancer is well documented to cause weight loss and cachexia (1). An inflammatory process driven by the presence of a tumour, can result in reduced food intake (2), increased metabolic output (3) and loss of skeletal muscle (1). They have reduced fitness and feeling of lethargy that affects activities of daily living and quality of life. The process explaining this is not well understood but thought to be due to diminished skeletal muscle mass and performance. When cancer patients undergo surgery, the trauma of surgery, entails an inflammatory process that furthermore leads to more of the above (4). Reducing this inflammatory insult would positively impact fitness, ability to respond to infections, affect length of stay in hospital, recovery from surgery and quality of life following surgery.

Eicosapentaenoic acid (EPA) is an omega-3-fatty acid, derived from fish oil and a commonly available nutritional supplement. It is believed to reduce the inflammatory effect of cancer and the trauma of surgery, in turn dampening the catabolic effect causing skeletal muscle loss. Studies on oesophageal cancer patients have previously suggested that EPA can preserve lean muscle mass (5). The investigators expect EPA to cause less lean muscle loss and improved aerobic performance. High dietary intake is not thought to have health risks (6) and EPA has recently been trialed in infant milk formulas with no adverse effects (7).

The investigators plan to recruit patients from colorectal clinic, who are due to have surgery for colorectal cancer, and give them EPA or placebo, from 5 days prior to surgery to up to 21 days following surgery. The investigators would like to measure markers of muscle function and inflammation, muscle mass, exercise performance on by cardiopulmonary exercise testing, muscle biopsy and muscle grip strength on a dynamometer.