CA 15-3 Test

Test Results Interpretation

You received your CA 15-3 test results but still need help determining if they fall under the normal range. Read this section to know if your results range between the CA 15-3 normal value or higher.

What Does CA 15-3 Test Results Mean?

Generally, the higher the CA 15-3 level, the more cancer is present in the body. The levels are typically highest when breast cancer has spread to the bones or liver ².

If your CA 15-3 level decreases or returns to normal, it may mean your treatment is working. An increase in CA 15-3 overtime could indicate your cancer is not responding well to treatment, is still growing, or has recurred.
CA 15-3 can also be elevated in some non-cancer conditions like endometriosis, pelvic inflammatory disease, liver disease, and pregnancy. However, the levels are usually not as high and do not continue increasing over time as they can with cancer ³.

What Is the normal range for the CA 15-3 test?

Levels	Interpretation	Conditions
More than 30 U/mL⁴	CA 15-3 blood test Mild to moderate range	Cancer of the breast, lung, pancreas, ovary, and prostate as well as endometriosis, pelvic inflammatory disease or pregnancy ⁵.
Less than or equal to 30 U/mL.	CA 15-3 blood test normal range	-

What Medical Conditions Can Cause High CA 15-3 Levels?

High levels of CA 15-3 cancer marker test indicate the presence or spread of breast cancer, but they can also be caused by benign conditions of the breast, ovary, liver, lung, and gastrointestinal tract.

What Medical Conditions Can Cause Low CA 15-3 Levels?

Low levels of CA 15-3 are generally considered normal and are not typically associated with specific medical conditions ⁶. In the context of monitoring breast cancer, lower or decreasing levels of CA 15-3 are usually seen as a positive sign, indicating that the treatment may be effective or that the cancer is in remission.

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FAQs Around CA 15-3 Test

What is CA 15.3 test used for?

The CA 15.3 test is used to measure the level of cancer antigen 15-3 (CA 15.3), a protein produced by some types of breast cancer cells. The test is primarily used to monitor the treatment of breast cancer and to assess the risk of recurrence.

How is CA 15.3 test performed?

The CA 15.3 test is performed by taking a blood sample, usually from a vein in the arm, and sending it to a laboratory for analysis. The procedure is quick, simple, and painless.

What are normal results of CA 15.3 test?

The reference values for CA 15.3 test vary based on the laboratory, but generally, a CA 15.3 level of less than 31 U/mL is considered normal. However, it is important to note that normal values may vary depending on the patient's age, sex, and overall health.

How reliable is CA 15.3 test?

The reliability of the CA 15.3 test varies, and false-positive and false-negative results are possible. The test is not used to diagnose breast cancer but rather to monitor the treatment of breast cancer in women who have already been diagnosed. The results should be interpreted in conjunction with other tests and examinations.

Are there any side effects of CA 15.3 test?

The CA 15.3 test is a simple blood test and has no significant side effects. The procedure is quick, simple, and painless.

How often should I get a CA 15.3 test done?

The frequency of CA 15.3 testing is determined by your healthcare provider based on your individual case. It is typically performed regularly to monitor the treatment of breast cancer and assess the risk of recurrence.