What Is a HER2 Positive Breast Cancer Diagnosis?

 Posted on January 24, 2022 in Medical Malpractice

Cook County Misdiagnosis Injury LawyerBreast cancer is one of the most well-understood forms of cancer and the field of treatment and diagnosis is continually evolving and improving. Illinois doctors like radiologists and oncologists who work with breast cancer patients are responsible for constantly pursuing appropriate education so they can give their patients an appropriate standard of medical care. When doctors fail to do this, test results can be delayed, misdiagnosed, or poorly managed, leading to adverse patient outcomes and a possible medical malpractice lawsuit. If you have been diagnosed with HER2 positive breast cancer, it may be helpful to learn more about what this means so you can ensure you are getting what you need. 

What is the HER2 Gene? 

The “human epidermal growth factor receptor 2,” or HER2, is a gene that can contribute to the growth of breast cancer. When a breast tissue biopsy is performed, a written report will have specific information about the tissue, including whether HER2 plays a role in a specific patient’s cancer development. 

More specifically, the HER2 gene creates HER2 proteins that help healthy breast cells grow, divide, and repair themselves. But for an estimated 10 to 20 percent of breast cancer patients, HER2 genes do not work properly. When this happens, HER2 cells may make too many copies of themselves, leading to uncontrolled cell growth and division. 

If a breast cancer biopsy shows the presence of HER2 protein overexpression (i.e., the presence of too many HER2 proteins), the pathology report will say that the breast cancer is HER2-positive. Understanding whether breast cancer is HER2 positive is crucial for ongoing treatment and diagnosis, because HER2-positive breast cancers often spread and grow faster, and tend to come back more quickly and aggressively than HER2-negative breast cancers. 

How is HER2 Status Tested? 

There are several tests that indicate whether breast cancer is HER2 positive. The two most common tests are: 

  • The FISH Test - A fluorescence in situ hybridization (or FISH) test uses special chemicals that attach to HER2 proteins and become fluorescent. The FISH test is the most accurate HER2 indicator test available, but it takes longer to get results and is more expensive.

  • The IHC Test - The ImmunoHistoChemistry, or IHC, test stains HER2 proteins with special chemical dyes. Then, the IHC test measures how many HER2 proteins are present on the surface cells of a breast tissue biopsy. The results are scored on a range from 0-3+. If a result is 2+ or higher, it could be HER2-positive. If a test is borderline positive, a doctor may order a FISH test to further determine whether a tissue sample is HER2 positive. 

Call a Chicago Breast Cancer Misdiagnosis Lawyer

At Winters Salzetta O'Brien & Richardson, LLC, we are committed to helping all of our clients seek justice and rightful compensation when they may be a victim of medical malpractice. If you believe you have suffered from a breast cancer misdiagnosis or another form of breast-cancer-related medical malpractice, call our offices today to schedule a free case review with a Cook County breast cancer misdiagnosis attorney. We are ready and waiting to hear from you. Call us at 312-236-6324



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