Serum sialic acid levels in lung cancer patients.

The levels of N-acetyl neuraminic acid (sialic acid) in normal men and pre-and post-menopausal women were determined. Smoking post-menopausal estrogen therapy, oral contraceptives, and refreezing had no effects on sialic acid levels. Pre-treatment values from patients with lung carcinoma showed markedly elevated levels of sialic acid (0.697 +/- 0.149 muM/ml) as compared to those from normal controls (0.432 +/- 0.067 muM/ml). The potential usefulness of sialic acid as a biological marker is discussed.