Dietary fat, arachidonic acid metabolism and lipid peroxidation have a
ll been implicated in colorectal carcinogenesis. Fatty acids, prostagl
andins (PGE(2), PGF(2a)) and malondialdehyde (MDA), the stable end-pro
duct of lipid peroxidation of polyunsaturated fatty acids (PUFAs), wer
e studied in paired tumour and normal mucosa of 20 patients with color
ectal cancer. Levels of arachidonic acid and total PUFAs were increase
d in the phospholipid fraction of tumours (P<0.05). Levels of PGE(2) a
nd MDA were also higher in tumours (P<0.001) and there was a significa
nt correlation between MDA and PGE(2) concentrations (r(s)=0.69, P<0.0
1). In contrast to previously reported in vitro studies, this work sug
gests that lipid peroxidation may be enhanced in human colorectal tumo
urs. As PGE(2) and MDA have been shown to be involved in carcinogenesi
s, these may be considered potential therapeutic targets for preventin
g or treating colorectal carcinoma.