A New Test for Breast Cancer

Is a blood test for breast cancer on the horizon? Scientists have discovered that levels of a marker in the blood called epidermal growth factor receptor or EGFR is higher in a woman’s blood prior to being diagnosed with breast cancer. This could eventually make it possible to diagnose breast cancer at an earlier stage using blood markers like EGFR in conjunction with mammography.

Testing for Breast Cancer Using EGFR

A group of 420 women with estrogen receptor positive breast cancer had their blood drawn seventeen months prior to receiving a breast cancer diagnosis. Compared to a control group without breast cancer, women with estrogen receptor positive breast cancer had higher levels of EGFR in their bloodstream. Researchers found that women with the highest levels of EGFR were 2.9 times more likely to be diagnosed with estrogen receptor positive breast cancer in the following seventeen months compared to those with the lowest levels.

An EGFR lab test could be even more important for predicting breast cancer in women taking hormone replacement therapy. Women on hormone replacement therapy who had the highest levels of EGFR were at a nine times greater risk of being diagnosed with estrogen receptor positive breast cancer relative to women with low levels of this marker.

Still, the EGFR lab test isn’t the perfect for diagnosing breast cancer. The specificity of the test was ninety percent, but its sensitivity was only 31 percent. This means if the test shows high levels of EGFR in the blood, it’s accurate ninety percent of the time. On the other hand, it’s not very sensitive which means levels of EGFR don’t rise in 69 percent of the cases where women have estrogen receptor positive breast cancer. With its low sensitivity, this test is still going to miss a lot of breast cancers.  

EGFR Lab Test for Breast Cancer: The Bottom Line?

The EGFR lab test certainly has its limitations – including a lack of sensitivity – so doctors are unlikely to find it useful when used by itself. The hope is that other blood markers can be identified that could be used in combination with EGFR to make the test more sensitive and even more specific. Until then, mammography and breast MRI are still the best options for breast cancer screening.  

References:

http://www.medicalnewstoday.com/articles/186107.php

Medical News Today website. “Increased EGFR Levels May Be An Early Marker Of Breast Cancer”.