Simple Blood Test May Identify Breast Cancer Recurrence

Patient Expert

"Will a blood test tell me if my cancer has come back?" Wouldn't that be great, if it were so simple! There's currently no blood test that will categorically confirm a breast cancer recurrence. But thankfully, one may be in the works.

Breast cancer is a tough disease. It can kill you if not treated; and the treatments are difficult. Still, about 7 out of 10 women survive breast cancer, and eventually die of another cause.

Human nature being what it is, though, most of us don't blithely assume we'll be on the positive side of that statistic. Instead, we worry about being one of the unlucky ones whose cancer returns. And, feeling that the earlier we catch a recurrence the more chance we have of surviving, we wonder: isn't there some simple blood test that shows whether or not you have active cancer?

There's no blood test for breast cancer recurrence – yet.

Currently, there's no such test. You may have heard other breast cancer survivors describe getting a test that showed their "markers were elevated." They're probably talking about the CA 27.29 test, which monitors the level of a certain cancer antigen in the blood. Theoretically, the higher the level of antigen, the more likely it is that cancer is active somewhere in the body.

Existing tests – CA 27.29, CEA, and CA 15-3 – aren't reliably accurate.

Unfortunately, the CA 27.29 isn't very accurate. It's been in use for nearly 20 years, but over time oncologists and researchers have discovered that it produces a lot of false results, both positive and negative.

The test does work well for women with an identified metastasis, and helps doctors monitor the success (or failure) of various treatments. But to identify whether or not cancer has spread? Not so good.

Two other tests oncologists sometimes perform, the CEA and CA 15-3 tumor marker tests, have similar lack-of-success rates.

So, for the moment we're left with being aware of physical signs of recurrence: a nagging cough; bone pain; recurring headaches. All of which can (and usually do) point to other, non-cancer-related medical issues.

A new test, cMethDNA, shows strong promise.

But a new blood test, the cMethDNA assay, can identify breast cancer genes in a woman's blood, and then see whether they've undergone hypermethylation: part of a process that keeps cancer cells from growing. Where there's smoke, there's fire: if cancer cells are being "silenced," that means they've become active.

Yes, the test is involved (on the back end at least); it's not as simple as just finding cancer cells in the bloodstream. But researchers claim that cMethDNA is up to 95 percent accurate at identifying breast cancer recurrence – within as little as two weeks after it begins.

The researchers at Johns Hopkins Kimmel Cancer Center who developed the test say not only can it be used to identify recurrence early, but to monitor treatment, such as: is chemo working? Would a different drug work better? Rather than wait months to see if treatment is effective, cMethDNA can make that assessment in just a couple of weeks.

National trials will test cMethDNA's effectiveness.

The test is currently involved in ongoing national trials designed to test and re-test its efficacy. But early results are promising. It looks like a simple blood test that can reveal breast cancer recurrence may actually become available in the not-so-distant future.

See more helpful articles:

A Guide to Breast Cancer Symptoms

When It Spreads: Breast Cancer Metastasis

Metastatic Breast Cancer Awareness: Speaking Out for the 30 Percent


Love, Susan. "Metastatic Disease" – Dr. Susan Love Research Foundation | Breast Cancer – accessed August 14, 2015.

Whiteman, Honor. "New Blood Test 'accurately Predicts Breast Cancer Recurrence' " Medical News Today. April 15, 2014. Accessed August 14, 2015.

Breast cancer survivor and award-winning author PJ Hamel, a long-time contributor to the HealthCentral community, counsels women with breast cancer through the volunteer program at her local hospital. She founded and manages a large and active online survivor support network.