Tumor marker CA 19-9: features, decoding, specificity

Synonyms: CA 19-9, carbohydrate antigen 19-9, 19-9 Ca, cancer antigen CA 19-9, 19-9 Cancer Antigen

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Scientific editor: M. Merkusheva, PSPbGMU them. Acad. Pavlov, general medicine.
October, 2018.

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Overview

Tumor marker CA 19-9 - is a laboratory component, determining the presence of malignant tumors of the pancreas, the second important after CEA. Identification of CA 19-9 in the blood to diagnose carcinomas early, inflammation of the pancreas (e.g., pancreatitis), and pathology of other internal systems.

Analysis of CA19-9 informative and for monitoring the effectiveness of conservative or operative treatments of cancer. In addition, this study is an important criterion in the diagnosis of cancer processes in the large intestine with a negative test result to carcinoembryonic antigen (CEA).

CA19-9 - a high glycated protein, which is produced in the body of the embryo and adult epithelia of internal organs: stomach, liver, renal, biliary tract, prostate, bronchial, salivary glands, pancreas, uterus, etc. Also, tumor markers can be detected in the composition of biological fluids (bile, ejaculate, blood plasma, pancreatic secretion gland).

Excretion (excretion) antigen occurs together with bile. Therefore, when any violations secretion and / or outflow of bile there is a significant increase in tumor marker concentrations in the blood plasma. In order to differentiate the cause of CA 19-9 deviations from the norm and make an accurate diagnosis, in parallel with said test prescribed other blood tests for bile enzymes: alkaline phosphatase, GGT.

CA 19-9 is of great importance for the early detection of metastases of pancreatic tumors and monitor treatment.

CA19-9 recently considered the most specific (75-100%) and sensitivity (68-90%), a marker for early diagnosis and monitoring of therapy of pancreatic cancer. Medical Practice shows that at rates higher than 1000 IU / ml blood in 96% of cases in a patient diagnosed with inoperable carcinoma. Increase in blood component in 75-80% of cases indicates a carcinoma of the body, but in 25-20% of its normal level does not exclude cancer. This is due to the fact that about 5-7% of patients are negative for the Lewis antigen (in the body is not produced said glycoprotein). It is noted that this phenomenon is more common in patients evropioidnoy race. In this case, to clarify the results of the test shall be appointed to the CA 50.

CA 19-9 is not recommended for use as a screening test, i.e. test during planned inspections for detecting pancreatic cancer, because of its sensitivity (68-93%) and specificity (76-100%) are insufficient for accurate diagnosis of primary¹.

It is noted that increasing the level of the antigen and other gastrointestinal malignancies (in 60% of liver tumors in 50% of gastric cancers, 30% when straight carcinoma intestine).

Analysis of CA19-9 is highly informative to assess the risk of recurrence and metastasis of cancer (in conjunction with the test at the CEA in the blood), because in 90% of cases showing an increase of values ​​already for 3-6 months before the appearance of symptoms. That is why the CA 19-9 test is indicated for monitoring treatment of ovarian mucinous forms of cancer, as well as various forms of stomach cancer, colorectal cancer, and, of course, pancreatic carcinoma.

Indications for delivery

• Early differential diagnosis of malignant processes in pancreatic tissues (in conjunction with the analysis on the SA 50);
• Preclinical prediction of risk of metastasis and recurrence of pancreatic cancer;
• Evaluating the effectiveness of the treatment of pancreatic cancer;
• The monitoring of the healing process of patients with cancer of the stomach (combined with CEA);
• Diagnosis of colorectal cancer (in combination with REA);
• Screening for mucinous ovarian cancer forms (together with NO 4 and CA 125);
• Chronic inflammation of the pancreas, clinical signs of benign or malignant tumors (stomach cramps, nausea, weight loss unfounded, jaundice, etc.);
• Diagnosis of other internal cancers: bladder and gall ducts, kidneys, liver, intestine, prostate, respiratory organs, etc .;
• Diagnosis and treatment of pancreatitis.

The interpretation of the test results on the tumor marker CA 19-9 is carried out highly specialized doctors: surgeon, oncologist, hepatologist, infectious disease, endocrinology and others.

normal values

Important! Norms vary depending on the reagents and equipment used in a particular laboratory. Therefore, when interpreting the results it is necessary to use standards adopted precisely in the lab where to be tested. It is also necessary to pay attention to the units.

Reference range, most often occurring in all:

• 0 - 37 IU / ml.

Complete absence of the antigen is the norm. The higher the level of CA 19-9, the higher the risk of a malignant process and its later stage, presence of metastases.

Elevated CA 19-9

Important! Interpretation of the results is always carried out comprehensively. An accurate diagnosis on the basis of only one analysis impossible.

A significant increase in more than 500 U / ml:

• Carcinoma of the pancreas;
• Bile duct cancer;
• Colorectal cancer;
• Oncology internal organs:
  • reproductive system: ovaries, endometrium, uterus, mammary glands;
  • Respiratory system: bronchi, lungs;
  • gastrointestinal tract: small and large intestines, the stomach;
  • other: liver, kidney, gall bladder, prostate, etc .;

CA19-9 increased slightly, up to 100, at least up to 500 U / ml:

• Liver disease in acute and chronic cirrhosis, hepatitis, failure, intoxication, benign tumors;
• Acute and chronic pancreatitis;
• Kidney or gallstone disease;
• Cholecystitis (Inflammation of the gallbladder);
• Cystic fibrosis (Gene mutation exocrine glands);
• Benign tumors of internal organs (adenomas, polyps, cysts, etc.);
• Autoimmune diseases: lupus erythematosus, sarcoidosis, sclerodermarheumatoid arthritis etc.
• Thyroid disease

In 0.5% of the increase in CA 19-9 detected in healthy patients.

Found a link between elevated serum CA19-9 (more than 37 U / ml), glucose metabolism disorder and the risk of developing metabolic syndrome².

Also the high values ​​of CA 19-9 in diabetic patients suggest the need for additional tests and evaluation of the regulation of blood glucose levels³.

CA19-9 decreases

As a rule, lowering the level of CA 19-9 in the dynamics shows the effectiveness of the therapy.

Preparation for analysis

Material for the study: serum of venous blood.

Method biomaterial sampling: the antecubital vein venipuncture.

The recommended duration of treatment: the morning from 8.00 to 11.00.

Mandatory requirement: strict fasting, ie must be met before the procedure fasting period of at least 10 hours. By the use is permitted only pure non-carbonated water.

Additionally:

• kindly requested to inform the doctor about the current course of medical treatment or taking dietary supplements with the names, dosages of drugs, multiplicity and duration of their admission;
• eve excluded from the diet and alcoholic tonics, heavy (fried, smoked, spicy) food;
• 1-3 days if possible to limit the physical and emotional stress;
• Do not smoke for a few hours before the test;
• 30 minutes prior to analysis to ensure physical and mental rest.

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sources:

• 1. Nikhil G Thaker, MD. CA 19-9. - Medscape, Sep 05, 2014.
• 2. Du R., Cheng D. Association between serum CA 19-9 and metabolic syndrome: A cross-sectional study. - Journal of diabetes, 2017 Nov; 9(11).
• 3. Gul K., Nas S. CA 19-9 level in patients with type 2 diabetes mellitus and its relation to the metabolic control and microvascular complications. - The American journal of the medical sciences, 2011 Jan; 341(1).