Serum sialyltransferase levels as a parameter in the diagnosis and follow-up of gastrointestinal tumors.

Serum sialytransferase (SST) levels were determined in patients with various gastrointestinal cancers at different clinical stages. These SST values are significantly elevated over normal healthy controls, and a correlation was observed beteen tumor stage and SST activity. While SST levels rise in patients with increasing tumor burdens, they revert to normal in patients with undetectable tumor tissue after radical surgery. In a group of patients, carcinoembryonic levels were determined along with SST values, and both sets of data were correlated to the clinical diagnoses. The usefulness of SST determinants in the diagnosis and follow-up of gastrointestinal tumors is discussed.