CHANGES OF THE MUCOSAL N3 AND N6 FATTY-ACID STATUS OCCUR EARLY IN THECOLORECTAL ADENOMA-CARCINOMA SEQUENCE

Despite data favouring a role of dietary fat in colonic carcinogenesis , no study has focused on tissue n3 and n6 fatty acid (FA) status in h uman colon adenoma-carcinoma sequence. Thus, FA profile was measured i n plasma phospholipids of patients with colorectal cancer (n=22), spor adic adenoma (n=27), and normal colon (n=12) (control group). Addition ally, mucosal FAs were assessed in both diseased and normal mucosa of cancer (n=15) and adenoma (n=21) patients, and from normal mucosa of c ontrols (n=8). There were no differences in FA profile of both plasma phospholipids and normal mucosa, between adenoma and control patients. There were considerable differences, however, in FAs between diseased and paired normal mucosa of adenoma patients, with increases of linol enic (p=0.02), dihomogammalinolenic (p=0.014), and eicosapentaenoic (p =0.012) acids, and decreases of alpha linolenic (p=0 001) and arachido nic (p=0.02) acids in diseased mucosa. A stepwise reduction of eicosap entaenoic acid concentrations in diseased mucosa from benign adenoma t o the most advanced colon cancer was seen (p=0 009). Cancer patients s howed lower alpha linolenate (p=0.002) and higher dihomo gammalinolena te (p=0.003) in diseased than in paired normal mucosa. In conclusion c hanges in tissue n3 and n6 FA status might participate in the early ph ases of the human colorectal carcinogenesis.