Serum beta-carotene, vitamin E, vitamin C and malondialdehyde levels in several types of cancer.

We measured the levels of serum carotenoids (beta-carotene), total tocopherol (vitamin E), ascorbic acid and malondialdehyde (MDA) in newly diagnosed cancer cases. Levels of the antioxidants and MDA in serum samples from 208 subjects with cancer affecting different sites (59 breast, 38 head and neck, 46 genitourinary, 12 lung, 20 gastrointestinal and 33 other sites) were compared with levels in 156 controls. Cases and controls were compared with respect to a number of potentially confounding factors: age, sex, smoking status, Quetelet index (kg/m2), diet and alcohol intake. Mean (+/- SD) levels of beta-carotene, vitamin E and vitamin C were significantly lower among the cases than the controls (49.35 +/- 36.55 micrograms/l, 0.60 +/- 0.14 mg/dl, 0.40 +/- 0.27 mg/dl and 75.31 +/- 28.59 mg/dl, 0.98 +/- 0.13 mg/dl, 0.88 +/- 0.47 mg/dl, respectively) (P < 0.05). On the other hand, mean levels of MDA were significantly higher among the cases than the controls (6.79 +/- 1.22 nmol/ml and 3.52 +/- 0.97 nmol/ml, respectively) (P < 0.05). The results obtained suggest that measurement of serum antioxidants and MDA levels may provide further useful information when evaluating cancer patients.