What does the analysis for the tumor marker CA 19-9
Specific antigen CA 19-9 is produced by cancer cells of the pancreas, at least – of the stomach and liver. Due to free entry into the bloodstream, this protein is an effective marker of the tumor. The antigen is excreted exclusively in the bile, therefore, any violation of metabolic processes in the liver accompanied by the increase of its concentration. The tumor marker CA 19-9 has high specificity and is therefore not suitable for screening.
10% of people did not possess the gene encoding the antigen CA 19-9, therefore, even when a malignant tumor level of tumor marker in the serum is not defined.
When assigned to the analysis
First, such a study is carried out for suspected pancreatic cancer: abdominal pain, jaundice, nausea and weight loss. Study on the tumor marker CA 19-9 is performed for the control of the malignant process, determining the effectiveness of treatment and diagnosis of metastasis. If you suspect a tumor in other organs of the gastrointestinal tract analysis is necessary to take in combination with other tumor markers.
Due to the fact that the level of tumor marker CA-19-9 depends on the technique used, repeated testing is desirable to carry out the same method in the same laboratory.
What do the results of the analysis
Normally, the rate of tumor marker CA 19-9 is 0-35 u/ml. the absence or low level in blood is characteristic for a healthy person. In pancreatic cancer, the CA 19-9 level is elevated in 75% of patients. As a rule, the higher the antigen level in the blood, the more advanced stage of the disease in the patient. Sometimes, its concentration slightly increases in tumors at other sites, as well as diseases of the liver, gallstones, pancreatitis and cystic fibrosis. To avoid unreliable results, the doctor recommends to take parallel biochemical analysis of blood. The proper and sensible interpretation of the analysis can only be done by a specialist.
How to prepare for testing
For studies used venous blood, the patient should be fasting (more than 8 hours after the last meal). Preferably 3 days before the test avoid alcohol, fatty and spicy foods. When carrying out antitumor treatment is recommended assays for CA 19-9 tumor markers every 4 months.