Oncomarker of the breast - CA 15-3: interpretation of the norm

Carbohydrate antigen 15-3 is produced by normal breast cells. This is a high molecular weight mucin-type compound.

In clinical practice, his research is used to detect oncology in women over 18 years of age. He has a low enough sensitivity, so sometimes in the early stages of the disease does not show increased results.

Description and significance of the CA 15-3

cancer marker Cancer antigen reveals 40-60% of relapses 2-18 months before the onset of symptoms. Particularly strong increase in metastases in bone and liver.

Such a blood test is informative, but not unique, as it reveals a tumor not only in the mammary gland.

It rises with the processes in the lungs, the liver. Because of this, other methods of investigation are used to confirm the diagnosis. The diagnostic value is a combination of CA 15-3 and the determination of the level of cancer-embryonic antigen.

The main property of the oncomarker is its high concentration is observed in the absence of cancer, and in newly inf

ected patients the content may be within the normal range.


Indications for delivery of blood to oncomarker 15-3 Direction is issued by an oncologist for:

  • monitoring of breast cancer progression,
  • metastasis determination,
  • study of the efficacy of carcinoma treatment,
  • differential cancer diagnosis and benign mastopathy.

Sometimes blood for study is taken for the initial diagnosis. At the same time, the number of several markers is studied at once.

Indicators will be false if the subject has tuberculosis or autoimmune diseases. It also increases during pregnancy.

How to take the test correctly?

You can go through the examination in almost any medical laboratory. For analysis, blood from the vein is taken. On the day of the study, you can not eat, and 30 minutes before the start, do not smoke. On the eve it is allowed to drink water without gas.

Do not come to the study after physiotherapy. Exclude for a day thermal exposure and manual examination of mammary glands.

Interpretation of the analysis results for the CA 15-3

oncologist. The transcript of the study helps to make a decision to perform conservative treatment when the operation becomes impossible. The result is from 3 hours to two days.

More often the method is used in permanent patients of oncological clinics or when obtaining thresholds.

When deciphering the results, the root cause of the disease is established, the effectiveness of the selected methods is determined. If the indicators are at the borderline, then a mammogram and a biopsy are performed.


Good performance СА15-3 - up to 22 IU / liter. They indicate:

  • no cancer,
  • early oncology stage,
  • the success of the treatment.

Please note: a single increase in the oncomarker is not always an "alarm bell", as external factors can influence the results.

It is recognized that the normal value in healthy women should not be more than 13, 4 +/- 6.5 U / ml. The threshold limit( 20 to 30 U / ml) indicates possible benign breast tumors or mastopathy.

Along with this, the possibility of having cancer cells increases. Additional examinations are required.


The reasons for the increase of the CA 15-3 tumor markers Increase in the norm( from 30 units / ml) indicates:

  • breast carcinoma,
  • stomach cancer,
  • oncology of the liver or pancreas,
  • female genital cancer.

Raising CA15-3 may occur in the third trimester of pregnancy, with benign breast tumors and with cirrhosis of the liver.

Very high level( above 50 U / ml) indicates the late stages of cancer. According to such data the doctor can assume the presence of metastasis. During this period, the patient usually already knows about his problem. Therefore, it is important to exclude liver cirrhosis and pregnancy.

If fibroadenoma is found before the test, mastopathy, and the results are sharply overestimated, a diagnosis is required. Then the dynamic control of CA 15-3 is carried out.

The protein content of the blood changes because of the complex biochemical reactions taking place in the blood. Therefore, the information obtained should be checked to exclude the presence of cancer.

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