Eicosapentaenoic acid (EPA) is a naturally occuring omega-3 polyunsaturated fatty acid found in oily fish. EPA has anti-colorectal (bowel) cancer activity in experimental models. This trial will test whether EPA reduces markers of tumour growth, and is safe and well tolerated,in patients with colorectal cancer liver metastases awaiting surgery.

A double-blind, randomised, placebo-controlled trial of eicosapentaenoic acid (EPA), in the free fatty acid form, 2g daily in patients who will undergo liver resection surgery for colorectal cancer liver metastases.

Inclusion Criteria:

• Age greater than or equal to 18 years
• Either sex
• Liver resection deemed clinically appropriate for management of metastatic colorectal cancer
• Duration between decision to perform liver resection and surgery greater than 2 weeks
• Ability to give written informed consent and follow study protocol
• Telephone contact possible

Exclusion Criteria:

• Neo-adjuvant chemotherapy for colorectal cancer (CRC) liver metastasis
• Chemotherapy for any cancer in the previous 3 months
• Known bleeding diathesis or anticoagulation therapy
• Fish or seafood allergy
• Use of fish oil supplements (eg. cod liver oil) and unwilling to stop for the duration of the study
• Pregnancy
• Non-aspirin non-steroidal anti-inflammatory (NSAID) or corticosteroid use
• Renal impairment (serum creatinine >150)
• Active inflammatory disease (e.g. Inflammatory Bowel Disease, Rheumatoid Arthritis).