[Sialic acid in the serum--an indicator for malignant growth?].

Changes of the sialic acid content of patients sera reflect growth processes of benign and malignant character. Using an enzymatic test the value of sialic acid as a primary diagnostic parameter has been investigated. We found a poor diagnostic sensitivity with exception of lung and ovarian carcinomas where the sensitivity attained nearly 90%. In monitoring of patients with pre-therapeutically elevated sialic acid content in serum dropping values indicate a successful therapeutic intervention. An increase of post-therapeutic values demonstrates recurrent processes but the reaction of the serum level may be delayed up to 2 weeks. The outcome of the studies supports the notion that sialic acid is a tumor marker of very limited value.