STUDY OF LIPID-PEROXIDATION IN PATIENTS WITH ESOPHAGEAL AND HEAD AND NECK-CARCINOMA TREATED WITH 5-FU

Background - Cardiotoxicity is a serious but relatively unknown side effect of 5-fluorouracil (5-FU) treatment. The underlying pathophysiology of 5-FU-induced cardiotoxicity still remains poorly understood. In order to elucidate one possible mechanism behind this syndrome, we have studied whether 5-FU cardiotoxicity is associated with lipid peroxidation and thereby highlights the role of free radicals in the cardiotoxicity of 5-FU. Methods - Ten patients treated with 5-FU for malignancies in head and neck and esophagus were studied. Thiobarbituric acid-reactive substances (TBARS), an indicator of lipid peroxidation, were measured in plasma before treatment and on day 2 and 4 of treatment. Results - TBARS increased in four cases, decreased in five cases and remained unchanged in one case during treatment with 5-FU. Clinical features or ECG changes suggesting cardiac side effects, were observed in patients with both increased and decreased TBARS (in two and one patient respectively). Furthermore, TBARS increased in two patients who underwent 5-FU treatment uneventfully. Conclusions - This study does not support the hypothesis that lipid peroxidation could be the major limiting mechanism underlying the 5-FU-induced cardiotoxicity.