HER2 Positive Breast Cancer Treatment

Breast cancer is a group of diseases that affect any woman irrespective of their age. While diagnosing breast cancer, your doctor first tries to identify what type of breast cancer you have. This information will help him/her to know more about how cancer will behave and what treatment methods you should opt for. According to the American Cancer Society (ACS), about 13% of women in the United States will develop invasive breast cancer.

What Is HER2-Positive Breast Cancer?

During a breast biopsy, the tissue is tested for hormone receptors (HR). The tissue is also tested for human epidermal growth factor receptor 2 (HER2). Each of the tests reveals the development of breast cancer. In some test reports, HER2 is referred to as HER2/neu or ERBB2 (Erb-B2 receptor tyrosine kinase 2). Hormone receptors are called estrogen (ER) and progesterone (PR).

The HER2 gene produces HER2 proteins or receptors. These receptors are responsible for controlling the growth and repairing of breast cells. If HER2 protein is over-expressive, then it may cause irrepressible reproduction of breast cells.

HER2-positive breast cancers are more aggressive than HER2-negative breast cancers. Both HR and HER2 status help your doctor to choose the right treatment options for you. HER2-positive breast cancer treatment methods could be different from HER2-negative cancers.

Difference Between HER2-Negative & HER2-Positive Breast Cancer

HER2 proteins are indicators which reveal whether your breast cancer cells will divide and replicate or not. HER2-negative breast cancer is more common and it indicates that cancer cells are not making a lot of HER2.

HER2-positive breast cancer indicates that the cells are making a huge number of these hormone receptors. Thus, HER2-positive cancers are more aggressive.  

6 Causes of HER2-Positive Breast Cancer

HER2-positive breast cancer is more common among young women compared with HER2-negative cases. Though the exact causes of HER2-positive breast cancers aren’t known, certain risk factors may uplift your risk.

• Females are more prone to this type of cancer
• Give birth for the first time after age 30
• Being an obese
• Leading a sedentary lifestyle
• If you have a history of receiving radiation therapy in your chest area
• Smoking or other tobacco products

If you have a family history of breast cancer, then this will uplift your risk of getting this cancer. But HER2-positive breast cancer is not an inherited disease.

Top 6 Symptoms of HER2-Positive Breast Cancer

You can’t determine whether you have HER2-positive breast cancer or not. After checking your symptoms, the doctor will reveal whether you have breast cancer or not. Further tests are required to confirm if it is HER2-positive or HER2-negative.

You may experience the below-mentioned symptoms,

• A new lump in your breast or armpit areas
• Clear, colored, or bloody nipple discharge
• Excessive pain in your breasts
• Changes in your nipples or breast skin, such as dimpling, reddening, etc.
• Inverted nipples
• Swelling or changes in the size or shape of your breast

Diagnosis of HER2-Positive Breast Cancer

Your doctor will diagnose breast cancer in the following ways.

• Physical exam
• Medical history
• Imaging tests such as an ultrasound or mammogram

Based on the findings, your doctor may recommend a breast biopsy to test a small amount of tissue.

You may need to perform a HER2 test with the preferred method (an immunohistochemistry (IHC) test). Though all breast cells possess these proteins, an unusually large amount may indicate HER2-positive breast cancer. This will also uplift your risks of getting HER2-positive metastatic breast cancer.

An IHC test result is ranked according to the following ways,

• 0 to 1+ IHC, indicating HER2-negative cancer
• 2+, an “equivocal” result meaning that further testing is needed
• 3+, which indicates HER2-positive breast cancer

Additionally, breast cancer is marked on a scale of 0 to IV based on:

• Tumor size
• Cancer cell grading
• Estrogen and progesterone receptor status
• spread to lymph nodes
• spread to distant organs

Top 11 Treatment Methods for HER2-Positive

Though HER2-positive breast cancer is more aggressive than HER2-negative, treatment methods are wider. Depending on the stage, your doctor will recommend the best method or a combination of therapies.

• Surgery
• Radiation
• Chemotherapy
• Targeted therapy
• Hormonal treatment

1. Surgery

Women who have breast cancer may need some form of surgery to eradicate the tumors. Depending on the size, location, and the number of tumors, your doctor will decide whether you need a breast-conserving surgery or mastectomy, or only the removal of the lymph nodes.

Check the benefits and drawbacks of both breast-conserving surgery and a total mastectomy before making the decision.

2. Radiation

This type of therapy attacks the remaining cancer cells after surgery. It can also be used to shrink tumors. This treatment uses high-energy x-rays to kill cancer cells. Radiation therapy can be given either externally via a machine, or internally via catheters or needles.

3. Chemotherapy

Chemotherapy drugs are used to kill cancer cells anywhere in the body. This therapy also prevents cancer from spreading. Chemotherapy is effective for HER2-positive breast cancer.

4. Targeted Treatments

Targeted treatments are designed for specific areas of cancer cells. In the case of HER2-positive breast cancer, these drugs aim at cells that are producing excessive HER2 protein.

The targeted treatments for HER2-positive breast cancer include:

5. Trastuzumab (Herceptin)

this drug blocks cancer cells from receiving chemical signals that stimulate growth. This drug attaches to the HER2 protein and thus, blocks the receiving of growth signals. Trastuzumab was the first drug which was approved to target the HER2 protein. This drug plays a pivotal role in the treatment of HER2-positive breast cancers.

6. Pertuzumab (Perjeta)

This drug attaches to a different part of the HER2 protein. It is given intravenously and is also used in combination with trastuzumab.

7. Ado-Trastuzumab Emtansine (Kadcyla)

This intravenous drug combines trastuzumab with a chemotherapy drug called emtansine. This drug will uplift the survival rate in those with metastatic breast cancer or breast cancer that’s returned. This drug can be used after receiving chemotherapy and HER2-targeted therapy, before surgery.

8. Fam-Trastuzumab Deruxtecan (Enhertu)

The FDA approved this fam-trastuzumab deruxtecan in late 2019. This drug also combines trastuzumab with a drug called deruxtecan. This medication is ideal for HER2-positive breast cancer that has spread to other parts of the body. It is also useful for women with HER2-positive breast cancer that surgery can’t remove.

9. Neratinib (Nerlynx)

This prolonged drug is useful in the early stages of HER2-positive breast cancer. It is recommended for women who have completed a treatment regimen that includes trastuzumab. The prime objective of this drug is to lessen the likelihood of a recurrence.

10. Lapatinib (Tykerb)

Lapatinib blocks proteins that are responsible for unrestrained cell growth. It is useful when metastatic breast cancer becomes resistant to trastuzumab.

11. Tucatinib (Tukysa)

This medication was approved by the FDA in 2020. This drug also works inside the cell to block signals that are responsible for uncontrolled growth.

The Survival Rate of Breast Cancer

The typical survival rate is 5 years. But no specific research has been published regarding the survival rates for HER2-positive breast cancer alone.

Can HER2-Positive Breast Cancer Recur After Treatment?

HER2-positive breast cancer is more aggressive and may return. But recurrence happens only after 5 years of treatment. Due to the recently developed targeted treatments, recurrence is not common.

Conclusion

Nearly 3.8 million women in the United States are having breast cancer. But with the advanced targeted therapies, people can combat the early stages of HER2-positive breast cancer. Though the side effects of the treatment will disappear after the completion of the treatment course, you can work with your healthcare professional to manage the long-lasting effects.

Though metastatic breast cancers are not curable, treatments will help you to manage the symptoms. If a particular treatment won’t work, then you can try a combination of treatments to improve your condition.