What is HER2 positive breast cancer?

Breast cancer is not a single disease, but a variety of diseases, each with its own genetic characteristics. Each molecular subtype is treated differently from the others and with different results. Some breast cancers may be aggressive and unpredictable; Others are less biologically aggressive.

Clinicians are increasingly using genomic information about breast cancer cells to classify these cancers, typically categorizing them into at least four major subtypes: luminal A and luminal B, triple negative, and human epidermal growth factor receptor 2 positive. (HER2 for short). About one in five breast cancers are HER2-positive.

What is HER2?

HER2 is a gene found in healthy cells, but when it mutates, the body produces too many HER2 proteins, which can lead to breast cancer. Understanding the chemical and genetic makeup of a cancer, even if it is HER-2-positive, can help doctors recommend specific treatment and predict the likelihood of a tumor response. Invasive breast cancers are generally tested for HER2 levels in a hospital lab, using a sample of breast cancer tissue taken during a breast cancer biopsy or surgery.

“HER2-positive breast cancers are complex,” says Dennis Citrine, MB ChB, PhD, a medical oncologist at The Hospital of Chicago. “Compared to other types of breast cancer, HER2 grows quickly, is biologically more aggressive, and is more likely to spread. But we now have drugs designed to attack the HER2 protein. The introduction of Herceptin® (trastuzumab) was a watershed moment. I think the most significant advance In the treatment of breast cancer for the past 20 years has been the identification of HER2 and the development of a therapy that targets HER2.We now have five FDA approved drugs for HER2-positive breast cancer: trastuzumab, pertuzumab (Perjeta), lapatinib (Tykerb), and ado-trastuzumab emtancin (Cadchila). ), and neratinib (Nerlinx™).

Medicines such as trastuzumab are called targeted therapies and are designed to stop cancer cells from growing and spreading. Targeted drugs often have different side effects and are often less serious than chemotherapy. “HER2 medications are generally well tolerated and generally do not cause hair loss,” says Dr. Citrine. “But as a precaution, we have to monitor liver and heart function in patients taking targeted therapy drugs.”

HER2 الإيجابي positive breast cancer treatment

Some standard chemotherapy drugs may also be used to treat HER2-positive breast cancers, although these drugs do not specifically target the HER2 protein. Because some breast cancer patients do not benefit from current treatments that target HER2, and others become resistant after treatment for a certain period of time, researchers continue to test new or modified drug combinations. Including medicines designed to kill cancer cells without causing side effects.

Research recently published in the New England Journal of Medicine found that pertuzumab significantly improved outcomes for women with HER2-positive operable breast cancer when used in combination with trastuzumab and chemotherapy. Patients who took both drugs together had a 19 percent lower risk of invasive disease recurring compared to those who took trastuzumab alone. Since both bind to the HER2 receptor, albeit at different sites, pertuzumab and trastuzumab are believed to complement each other.

Several other clinical trials are looking at different combinations of treatments for HER2-positive breast cancer. Some studies have also found that immunotherapy may be a promising option for treating breast cancer. “Breast cancer immunotherapy is an active area of ​​research,” says Dr. Citrine. “It is very likely that immunotherapy has a role in treating some types of breast cancer.”