HER-2 Positive Breast Cancer: An Overview

What Is HER-2 Positive Breast Cancer?

HER2-positive breast cancer grows faster and is more aggressive than other breast cancers because the cancer cells have an abnormal level of a protein called HER2 (human epidermal growth factor receptor 2). This helps the cancer cells multiply quickly and increases the chances of the cancer returning.

Normally, HER2 helps control cell growth, but when its levels are too high, it causes uncontrolled cell division.

Early detection and targeted treatments that specifically block the HER2 protein can greatly improve outcomes. These treatments help slow down or stop the rapid growth of cancer cells and have significantly improved survival rates.

This type of cancer can also appear in other organs, such as the stomach, ovaries, bladder, and gastrointestinal tract. Around 20 % of all breast cancer cases are HER2-positive, and this subtype tends to be more aggressive with a higher chance of coming back.

What Are the Symptoms of HER2-Positive Breast Cancer?

HER2-positive breast cancer is often asymptomatic in its early stages, but some symptoms may be recognized. If you experience any of the following, consult your doctor immediately:

• A change in the size or shape of your breast.

• Clear or bloody discharge from the nipple.

• A small lump or mass, even the size of a pea.

• A hard or marble-like lump under the skin.

• Thickening or lumps near the breast or underarm that last through the menstrual cycle.

• A patch of skin on the breast that feels like an “orange peel”.

• Any new breast changes, such as puckering, redness, swelling, or discoloration.

What Causes HER2-Positive Breast Cancer?

• The pathogenesis of HER2-positive breast cancer involves the human epidermal growth factor receptor 2 (HER2) gene, which leads to the production of excessive HER2 protein on the surface of cancer cells. This abnormality in the HER2 gene is usually acquired during the development of breast cancer cells.

• The HER2 protein is essential for cell survival, division, and growth.

• The amount of HER2 protein is strictly controlled in healthy cells.

• But the HER2 gene is amplified or overexpressed in HER2-positive breast cancer, which results in an excess of HER2 protein.

• As a result, the HER2 pathway receives more signals, which encourages the unregulated growth and division of cancer cells.

How Is HERS-2 Positive Breast Cancer Diagnosed?

The most commonly used diagnostic test is immunohistochemistry (IHC), which assesses the protein expression of HER2 on tumor cells. Another test is fluorescent in situ hybridization (FISH), which detects HER2 gene amplification.

Both tests provide essential information to classify breast cancer as HER2-positive or HER2-negative. Early diagnosis and appropriate treatment interventions contribute to better prognosis and quality of life for patients with HER2-positive breast cancer.

1. Immunohistochemistry (IHC)

Procedure: IHC is a test that utilizes specialized antibodies to detect the HER2 protein on cancer cells. A small piece of the tumor is taken, stained with these antibodies, and then checked under a microscope. The amount and pattern of staining indicate the presence of HER2 protein.

Result :The results are scored as 0, 1+, 2+, or 3+:

• 0 or 1+ - HER2-negative.

• 2+ → borderline (needs another test like FISH).

• 3+ → HER2-positive (high HER2 protein).

2. Fluorescent In Situ Hybridization (FISH)

Procedure: FISH is a more advanced test that looks at the HER2 gene itself. It uses fluorescent (glowing) DNA (deoxyribonucleic acid) probes that attach to the HER2 gene inside the cancer cells. Under a special microscope, doctors can see how many copies of the HER2 gene are present.

Result: The number of HER2 genes is compared to a reference gene on chromosome 17.

• If the HER2 gene copies are much higher than normal, the cancer is HER2-positive.

What Are Treatments for HER2-Positive Breast Cancer?

HER2-positive breast cancer is highly treatable today. Doctors often use a combination of treatments. The exact plan depends on the stage of the cancer, the patient’s age, and overall health.

1. Targeted Therapy

Targeted therapy is the most important treatment for HER2-positive breast cancer. It focuses on blocking the HER2 protein so cancer cells cannot grow.

Common drugs include:

• Trastuzumab (Herceptin).

• Pertuzumab (Perjeta).

• Ado-trastuzumab emtansine (Kadcyla).

• Trastuzumab deruxtecan

These medicines attach to HER2 and stop cancer cells from receiving growth signals. They can also help the body’s immune system destroy cancer cells. They have greatly improved survival rates.

2. Chemotherapy

Chemotherapy is often used together with targeted therapy for HER2-positive breast cancer to improve treatment effectiveness and achieve better outcomes. It helps kill fast-growing cancer cells throughout the body.

Common chemotherapy drugs include:

• Docetaxel.

• Cyclophosphamide.

• Doxorubicin.

Often, chemotherapy will be given before surgery to reduce the tumor size or after surgery to reduce the chances of the cancer returning.

3. Hormone Therapy

If the tumor has hormone receptors (estrogen or progesterone receptors), hormone therapy may also be used. These medicines block hormones that help cancer grow.

Examples:

• Tamoxifen.

• Aromatase inhibitors.

Hormone therapy is usually given for several years to lower the chance of the cancer coming back.

4. Surgery

In most cases, surgery is performed by your doctor to remove the tumor.

Types of surgery include:

• Lumpectomy: Removal of the tumor and a small area around it.

• Mastectomy: Removal of the entire breast.

5. Radiation Therapy

Radiation therapy uses high-energy rays to kill remaining cancer cells. It is often done after a lumpectomy. This helps lower the risk of recurrence.

What Are the Risk Factors of HER2-Positive Breast Cancer?

The risk factors for HER2-positive breast cancer are mostly the same as those for general breast cancer. These factors may raise the risk of breast cancer, but the disease can still occur even in their absence.

The most common risk factors include:

• Age: The risk increases as you get older.

• Family History: The close relations of breast cancer increase your risk.

• Genetic Mutations: Mutations in genes, such as BRCA1 or BRCA2 (breast cancer gene 1 and 2 ), can predispose an individual to the risk.

• Hormonal Factors: The risk can be upgraded by beginning early, late menopause, or the use of hormone replacement therapy.

• Lifestyle Factors: Being overweight and drinking alcohol regularly can increase your chances.

• Radiation Exposure: If you have received radiation therapy to the chest earlier in life (for example, for lymphoma), this may increase the risk.

People who are assigned female at birth (AFAB) are more prone to getting breast cancer, but it can also rarely happen in people who are assigned male at birth (AMAB), too. Other medical conditions, like atypical ductal hyperplasia (a breast condition that is not cancer but increases risk), can also add to the likelihood.

Even though these factors increase risk, the outlook for HER2-positive breast cancer is much better today. When it is found early and treated properly, many people have a good life expectancy. The outcome depends on the cancer stage, the person’s age, and the specific type of tumor.

Can HER2-Positive Breast Cancer Be Prevented?

There is no guaranteed way to prevent HER2-positive breast cancer. The gene change usually happens randomly. But you can lower your overall risk of breast cancer by following a few preventive steps, like those mentioned below.

Ways to Reduce Risk:

• Get regular breast exams.

• Have screening mammograms as recommended.

• Maintain a healthy weight.

• Eat a balanced diet rich in fruits, vegetables, and whole grains.

• Exercise often.

• Limit alcohol intake.

• Avoid smoking.

Let us keep in mind that early detection helps and provides the best chance for successful treatment. Knowing your body and reporting any new breast changes can make a big difference.

Conclusion

To conclude, breast cancer that is positive with HER2 and early identification and prompt treatment are significant factors in enhancing effects and health. Frequent self-exams of the breast, frequent mammography screening of the breast, and prompt analysis of any changes in the breast facilitate the diagnosis of the disease at the stage of maximum effectiveness of treatment.

If you notice a lump, skin change, nipple discharge, persistent breast pain, or anything unusual, consult an oncologist on iCliniq without delay to receive the right diagnosis and targeted treatment.

Key Takeaways

• Early detection of HER2-positive breast cancer greatly improves survival and treatment success.

• Any breast lump, nipple discharge, or skin change should be checked by a specialist as soon as possible.

• Targeted therapy, combined with timely treatment and regular follow-up, is essential for better recovery and long-term health.