[Comparative research on serum N-acetylneuraminic acid determinations in tumor diagnosis].

N-acetylneuraminic acid (NAN) is determined in supernatants of perchloric acid as well as in chloroform/methanol extracts (lipid bound sialic acid) from sera of tumour patients. Compared to patients with other diseases, we do not find fundamental differences. In patients suffering from kidney tumours, bronchial and gastric carcinomas, the NAN values of both extracts are distinctly outside the range of the reference values. In most cases, acid alpha 1 glycoprotein is found to be the cause of the NAN concentration.