Biopsy Basics: HER2 Positive

HER2-Positive Breast Cancer is one that tests positive for a protein called “human epidermal growth factor receptor 2 (HER2) which causes cancer cells to grow.

Advocates for Breast Cancer - HER2 positive breast cancer
{We were unable to find the original sources of the two images we used. Please let us know if you do so we can attribute them accordingly.}
  • Approximately 1 out of every 5 breast cancers possess cancer cells which have a gene mutation which produces an excess of the HER2 protein
  • HER2 is more aggressive than other types of breast cancer.
  • HER2 breast cancers are not sensitive to hormone therapy – but many people with HER2-positive breast are still able to benefit from hormone therapy.

Excellently effective treatments for HER2-positive breast cancer are those that specifically target HER2 (see below). They are so effective, in fact, that the prognosis for HER2 is really positive!

Another light at the end of the treatment tunnel is the constant development of new medications, a number of which are currently undergoing clinical trials!


Even though some standard chemotherapy drugs don’t specifically target the HER2 protein, they can also be effective in the treatment of HER2-positive breast cancers.


When breast cancer recurs or spreads (metastatis), the cancer cells must be retested for hormone receptor status and HER2 because change in the cancer cells can very possibly evolve from the original diagnosis.


If medical jargon doesn’t sound like Chinese to you and you’d like to dig a little deeper into this topic, here is a great website which gives quite in-depth explanations (with images) about what breast cancer tissues look like under the microscope: HISTOLOGICAL DESCRIPTONS OF INVASIVE BREAST CANCERS by Dr Steven Halls, MD, FRCPC — a Canadian radiologist who designed a Breast Cancer Risk Calculator  and specialises in breast cancer research and oncologic imaging,  mammography, breast cancer biopsies, staging and follow-up scanning.  (NB: Whilst Google is a phenomenal source of information and online support, we always suggest that great caution be used when info-hunting. Always check out your findings with your medical team! )

This is a wonderfully frank, honest and real website called HER2 Support which is maintained by and for patients, caregivers, mothers, daughters, sons and husbands of breast cancer survivors who are HER2 positive. ‘We gather here to seek information about the illness. Here you will find newly diagnosed patients and long term survivors willing to share their experiences and knowledge.’