HER2-Positive Breast Cancer

HER2-positive breast cancer is a type of breast cancer that tests positive for the human epidermal growth factor receptor 2 (HER2) protein. Found on the outside of all breast cells, HER2 is involved in normal cell growth, division and repair. But sometimes, HER2 can be overexpressed and cause cancerous breast cells to grow and spread quickly.

Causes of HER2-Positive Breast Cancer

As with all types of breast cancer, what exactly causes HER2-positive breast cancer is unknown. It’s likely a combination of risk factors, including lifestyle and environment. Genetics are also thought to play a role. However, the HER2 gene is not inherited from parents and can’t be passed on to children.

Symptoms of HER2-Positive Breast Cancer

The main symptom of most breast cancers, including HER2-positive breast cancer, is a hard or rubbery lump in the breast that feels immovable.

Other breast cancer symptoms include:

  • Abnormal pain in breast or nipple
  • Changes in how the breast or nipples are shaped
  • Reddening, dimpling, swelling or thickening of breast skin
  • Discharge from the nipple that is not breastmilk

Diagnosing HER2-Positive Breast Cancer

Diagnosing most breast cancers begins with a biopsy to obtain a sample of breast tissue to test for cancer cells. The presence of the HER2 protein can be tested on the same sample.

Several tests that are used identify HER2 fall into two categories:

  • Immunohistochemical stains (IHC), which involves staining a tissue sample and observing color changes to the HER2 protein under a microscope
  • Fluorescent in situ hybridization (FISH) uses fluorescent pieces of DNA that stick to the HER2 protein and can be seen and counted under a microscope

Treatments for HER2-Positive Breast Cancer

The breast cancer experts at Tampa General Hospital’s Cancer Institute take a multidisciplinary approach to treatment and create individualized care plans for each patient. HER2-positive breast cancers are often treated with medications that specifically target and block HER2 receptors to keep cancer cells from growing. As a result, targeted therapies are quite effective in treating HER2-positive breast cancer.

Other treatments for HER2-positive breast cancer may include:

  • Chemotherapy
  • Radiation
  • Hormone therapy
  • Surgery