Sialyl transferase activity: a serum enzyme marker in the follow-up of cancer patients.

Clinical evaluation of serum sialyl transferase as a diagnostic tool in malignant disease has shown that there is a strong correlation between enzyme activity and extent of tumor tissue. Thus, patients with large tumor masses show higher enzyme activity than patients with small tumors or in remission. Furthermore, the surgical removal of tumor tissue results in a decrease of enzyme activity to the normal range. The values remain low until metastases recur; this is connected with a new increase in enzyme activity. It has also been shown that successful chemotherapy corresponding to tumor reduction is reflected in lower values. We are thus led to believe that sialyl transferase is a relevant diagnostic blood parameter in the follow-up of cancer patients.