Lipid peroxidation as additional marker in patients with colorectal cancer. Results of a preliminary study

Up to now, various tumor markers have been proposed for the detection of the onset of malignant cell transformation or the better follow-up of cancer patients. The aim of the present study is to investigate the diagnostic value of systemic lipid peroxidation as an additional evaluative tool in the follow-up of surgical patients with colorectal cancer in combination to the clinically routine tumor markers carcinoembryonic antigen (CEA) and carcinoantigen 19-9 (CA 19-9).

36 patients with a colorectal carcinoma were included in this study. Blood samples were collected 1 day prior to the operation, 10 days and 1 year after the operation. Oxygen free radical mediated lipid peroxidation was determined by measurement of thiobarbituric acid-reactive substances in the same serum that were used for the determination of tumor markers.

Compared to control values, a highly significant increase of lipid peroxidation was found in the serum of all colorectal carcinoma patients up to the first 10 postoperative days. Differentiation of the patients, according to the T-stage, showed a marked and more obvious tendency towards higher serum lipid peroxides with increased tumor stage when compared to the conventional tumor markers. One year postoperatively the serum levels of lipid peroxidation returned to nearly normal values. Also the conventional tumor markers CEA and CA 19-9 showed a relative rise in the levels with the respective tumor stage, but differences were only statistically significant in the highest T-categories.

After curative resection of the tumor, the level of systemic lipid peroxides decreases to normal values. We conclude from these results that the tumor is the primary cause of the increased systemic lipid peroxides.