Gene expression in colorectal liver metastasis tissues from EPA-treated patients

Eicosapentaenoic acid in its free fatty acid form (EPA-FFA), 2g daily, is safe and well-tolerated in patients undergoing liver resection surgery for colorectal liver metastasis.Oral EPA incorporates into colorectal liver metastasis tissue. EPA-FFA treatment is associated with reduced vascularity of liver metastases in ω-3 PUFA-naïve patients. Preoperative (median 30 days) EPA-FFA treatment may have prolonged benefit on postoperative overall and disease-free survival. We used whole genome expression array to study whether systemic CCL2 level changes were linked to a specific tumour gene expression profile in colorectal liver metastasis patients treated with EPA-FFA. 15 tumour RNA samples from colorectal liver metastasis patients treated with EPA-FFA during the EMT study (ClinicalTrials.gov NCT01070355) were extracted from formalin-fixed paraffin-wax embedded tissue blocks. The RNA samples were used for whole genome expression microarray experiments. We then performed a differential gene expression analysis to compare the tumour expression profile of patients with increased or decreased plasma CCL2 levels after intervention.