Cancer Ag-15-3

[marianne88]

Does anyone have any idea what tumor marker the above is for. Just noticed on my medical record that my doctor checked for this. Thanks

[PatSailsbery]

My oncologist runs three tumor markers: CA-27.29, CA-15-3, CEA.

I don't know what the AG-15-3 is for.

[Epinto]

That is the marker for breast cancer. Some hospitals do 15-3 and some 27-29. They both check for breast cancer.

[daf10]

How is it used?

The cancer antigen 15-3 (CA 15-3) test and the related CA 27.29 test are mainly used to monitor response to breast cancer treatment and to help watch for breast cancer recurrence. They are used along with other clinical evaluations and tests, such as estrogen and progesterone receptors, Her2/neu, and gene expression tests for breast cancer, to evaluate a person's breast cancer.

CA 15-3 is sometimes ordered to provide a general sense of how much cancer may be present (the tumor burden). CA 15-3 can only be used as a marker if the cancer is producing elevated amounts of it, so this test is not useful for all people with breast cancer.

The CA 15-3 and CA 27.29 tests are not sensitive or specific enough to use as a screening test for cancer because non-cancerous conditions can cause elevated levels.

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When is it ordered?

CA 15-3 may be ordered along with other tests when advanced breast cancer is first diagnosed to help determine cancer characteristics and treatment options. If CA 15-3 is initially elevated, then it may be ordered periodically to monitor the effectiveness of treatment and to help watch for recurrence. CA 15-3 is usually not ordered when breast cancer is detected early, before it has spread (metastasized), because levels will not be elevated in the majority of early cancers.

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What does the test result mean?

In general, the higher the CA 15-3 level, the more advanced the breast cancer and the greater the amount of cancer present (tumor burden). CA 15-3 concentrations tend to increase as the cancer grows. In metastatic breast cancer, the highest levels of CA 15-3 often are seen when the cancer has spread to the bones and/or the liver.

Increasing concentrations of CA 15-3 over time may indicate that a person is not responding to treatment or that the cancer is recurring.

Normal CA 15-3 levels do not ensure that a person does not have localized or metastatic breast cancer. It may be too early in the disease process for elevated levels of CA 15-3 to be detected or the person may be one of the roughly 20% to 25% of individuals with advanced breast cancer whose tumors do not shed CA 15-3.

Mild to moderate elevations of CA 15-3 are seen in a variety of conditions, including cancer of the lung, pancreas, ovary, prostate, and colon as well as cirrhosis, hepatitis, and benign breast disorders and in a certain percentage of apparently healthy individuals. The CA 15-3 elevations seen in non-cancerous conditions tend to be stable over time.

[marianne88 in reply to daf10]

Wow you have all the answers. Thank you so much. Both tests fall into normal range so I guess they can’t be used.

[Duranteg]

Daf10,

Thank you for the extensive explanation! It is very helpful.

Gwen

[Joan37]

The test is usually CA 15-3, with CA meaning cancer antigen. Maybe it's his handwriting? Check it out with him.

Others who replied noted addition tests, such as CA 27-29 and CEA. I've also had CA 125. They're all designed specifically to monitor breast cancer in our system but do not work for everyone, as daf10 noted. I think that CA 125 is often used as a marker for ovarian cancer.

My markers (and I've had all the markers listed here) have never been out of normal range even though I have MBC. For some patients, they work well and are an immediate tip-off that something is up, even if nothing appears yet on a scan. That is, their treatment could have stabilized their cancer, or resulted in NED and perhaps they continue to take only a targeted drug, such as an endocrine inhibitor (such as Tamoxifen or one of the AIs and fulvestrant) or one of the anti-HER2+ drugs.

My oncologist finally stopped doing them about two years ago.

[marianne88]

Thank you