Tumor progression and oxidant-antioxidant status.

Severity of prognosis factors in breast cancer cases was found to be associated with an increase in plasma vitamin E and a decrease in plasma malondialdehyde (peroxidability index). The first aim of this study was to determine whether this association is also present in other cancers. Measurements were taken before therapy on 129 patients with various carcinomas. Cholesterol was also investigated, as vitamin E is closely related to this analyte. Patients were classified by tumor size (T < or = 5 cm and T > 5 cm) and by invasion status, assessed by the presence of nodes and/or metastasis. The vitamin E/total cholesterol concentration ratio was higher and the cholesterol and malondialdehyde concentrations were significantly lower in the plasma of patients with large tumors or in whom nodes and/or metastasis were present, whatever the site. The multivariate analysis performed to measure the association of these analyte concentrations with tumor progression showed that the presence of nodes and/or metastases was inversely associated with a low vitamin E/total cholesterol ratio (OR, 0.5; CI, 0.3-1.1) and, directly associated with low plasma concentrations of cholesterol and malondialdehyde (OR, 3.0; CI, 1.3-6.8 and OR, 2.8; CI, 1.2-6.7 respectively). The same types of associations were identified with large tumors, but were less strong. Together these findings supported an alteration of lipid parameters related to the oxidant-antioxidant status in cancer patients. This alteration appears to be associated with tumor growth and progression in patients with various cancer sites.