Peter Makovník
Oncomarkers are specific substances produced by cancerous cells which are used in diagnosis and monitoring of various
cancers. In cancer of the biliary tract and pancreas most commonly used oncomarkers are carbohydrate antigen CA 19-9,
carcinoembryonic antigen and chromogranin A. All oncomarkers have limited use in diagnostics. The most common is
CA 19-9 and is used for monitoring patients after surgery and disease prediction during chemotherapy for pancreatic cancer.
Values below 37 U/ml help to distinguish benign pancreatic neoplasia. Patients with Lewis-negative blood group
(5-10% of population) are unable to produce CA 19-9. Specific hormonal substances e.g. serotonin, gastrin and others
have unique role in neuroendocrine tumours (NET). Chromogranin A is a nonspecific oncomarker for NET tumours.