Breast cancer is a form of cancer that develops in the breast cells. It is the most common form of cancer in women. It is vital to know that there are several types of breast cancer, and medical practitioners aim to identify the type as soon as a person has been diagnosed with this condition. The course of the disease and the recommended treatments depend on the type of breast cancer a person has.

Doctors will conduct a biopsy of the breast to check if the tissues have any specific hormone receptors (HR) like estrogen receptors or progesterone receptors. Additionally, they also conduct tests to see if any HER2 (human epidermal growth factor receptor 2) are present. Both these receptors are not only indicators of breast cancer but they also contribute to its development. The treatment options for HR- and HER2-positive breast cancer are determined on the basis of various individual factors.

Understanding HER2-positive breast cancer
HER2 proteins, also known as receptors, are created by the HER2 gene, and they are primarily responsible for controlling the growth as well as repair of healthy breast cells. When these proteins are overexpressed in the body due to the improper functioning of the HER2 gene, the reproduction rate of the breast cells spirals out of control. As a result of this, a patient diagnosed with HER2-positive breast cancer tends to be affected by a more aggressive form of cancer as compared to a patient who tests negative for the HER2 protein. Due to this, the treatments of HER2 breast cancer vary considerably.

Treatment options for HER2-positive breast cancer
The treatment plan for HER2-positive breast cancer usually involves a mix of therapies like chemotherapy, radiation, surgery, and targeted treatments. The doctor will usually consider various factors like the stage of the disease and the patient’s health before recommending any treatment plan.

• Surgery: Based on the number of tumors and their size and location, the doctor determines whether the patient requires a mastectomy (breast-conserving surgery), or removal of the lymph nodes.
• Radiation: It is performed for patients whose tumors need to be shrunk before surgery. In some cases, it is used to target the cancer cells that remain after surgery.
• Chemotherapy: It is a treatment that makes use of powerful medicines to target cancer cells and flush them out of the body or destroy them. It is a preferred option as it is one of the most effective forms of treatment for HER2 breast cancer. Sometimes, patients who test positive for HER2 breast cancer also test positive for HR breast cancer, and in such cases, a combination of hormone treatments would be needed along with other treatment options.

Targeted treatments for HER2-positive breast cancer
Some of the most common targeted treatments for HER2-positive breast cancer are:

• Trastuzumab: This medicine helps to block the cancer cells from receiving or reacting to the chemical signals which tend to spur the growth of cancer cells. In a study, women diagnosed with an early stage of HER2 breast cancer were given chemotherapy in addition to this targeted form of treatment. There was a significant reduction in the recurrence of cancer as well as the chances of survival. Data shows that the survival rate improved by close to ten years or more in about 84% of the tested subjects through the use of trastuzumab as compared to the 75.2% who relied only on chemotherapy.
• Ado-trastuzumab emtansine: Also known as trastuzumab emtansine, this medicine is a combination of trastuzumab and another popular chemotherapy medication called emtansine. Trastuzumab helps with the delivery of the chemotherapy medication directly to the HER-positive cancer cells. They inhibit cell division and the proliferation of cancer cells that overexpress HER.
• Pertuzumab: This medication can be used in patients with metastatic HER2-positive breast cancer that has not been treated with hormone therapy or chemotherapy. Alternatively, it can be used to shrink a tumor’s size before surgery in patients who have early-stage breast cancer.
• Lapatinib: This medicine works by blocking proteins that stimulate uncontrollable cell growth. It is used to treat advanced forms of breast cancer.

In general, once the specific treatments for HER2-positive breast cancer are completed, the doctor will set up periodic tests to check for any signs of recurrence or deterioration in the health of the patient. Usually, the side effects that occur due to the treatment will continue to improve over time. But in some cases, these effects may linger for life. It is crucial for patients to get enough information about each treatment plan for HER2-positive breast cancer and adhere to the do’s and don’ts to ensure that they get better soon.