HER2 Negative vs. HER2 Positive

Attribute	HER2 Negative	HER2 Positive
Definition	HER2 Negative refers to breast cancer cells that do not have an overexpression of the HER2 protein.	HER2 Positive refers to breast cancer cells that have an overexpression of the HER2 protein.
Treatment	HER2 Negative breast cancer is typically treated with hormone therapy, chemotherapy, and targeted therapies.	HER2 Positive breast cancer is typically treated with targeted therapies like trastuzumab (Herceptin), pertuzumab (Perjeta), and ado-trastuzumab emtansine (Kadcyla), in addition to hormone therapy and chemotherapy.
Prognosis	HER2 Negative breast cancer generally has a better prognosis compared to HER2 Positive breast cancer.	HER2 Positive breast cancer tends to have a more aggressive behavior and a poorer prognosis compared to HER2 Negative breast cancer.
Prevalence	HER2 Negative breast cancer accounts for approximately 80% of all breast cancer cases.	HER2 Positive breast cancer accounts for approximately 20% of all breast cancer cases.
HER2 Testing	HER2 Negative breast cancer is determined through HER2 testing, which measures the levels of HER2 protein in the cancer cells.	HER2 Positive breast cancer is determined through HER2 testing, which detects an overexpression of the HER2 protein in the cancer cells.

Introduction

HER2, also known as human epidermal growth factor receptor 2, is a protein that plays a crucial role in cell growth and division. It is found on the surface of certain cancer cells and can be either negative or positive. Understanding the attributes of HER2 negative and HER2 positive is essential in diagnosing and treating breast cancer. In this article, we will explore the differences between these two types of breast cancer and their implications for patients.

HER2 Negative

HER2 negative breast cancer refers to tumors that do not overexpress the HER2 protein. Approximately 80% of breast cancers fall into this category. HER2 negative tumors tend to grow at a slower rate compared to HER2 positive tumors. They are also less likely to spread to other parts of the body, making them generally associated with a better prognosis.

Patients with HER2 negative breast cancer often have different treatment options compared to those with HER2 positive breast cancer. Hormone therapy, such as tamoxifen or aromatase inhibitors, is commonly used for HER2 negative tumors that are hormone receptor positive. Chemotherapy may also be recommended, depending on the stage and characteristics of the tumor.

HER2 negative breast cancer is typically diagnosed through a combination of imaging tests, such as mammograms or ultrasounds, and a biopsy to analyze the tumor tissue. Genetic testing may also be performed to determine the presence of specific gene mutations that could impact treatment decisions.

While HER2 negative breast cancer generally has a more favorable prognosis, it is important to note that each case is unique, and individual factors such as tumor size, grade, and lymph node involvement can influence the overall outcome.

HER2 Positive

HER2 positive breast cancer, on the other hand, refers to tumors that overexpress the HER2 protein. Approximately 20% of breast cancers fall into this category. HER2 positive tumors tend to grow more rapidly and are more likely to spread to other parts of the body, leading to a higher risk of recurrence and a potentially worse prognosis.

Patients with HER2 positive breast cancer often have targeted therapy options available to them. One such treatment is trastuzumab (Herceptin), a monoclonal antibody that specifically targets the HER2 protein and inhibits its activity. Other targeted therapies, such as pertuzumab (Perjeta) and ado-trastuzumab emtansine (Kadcyla), may also be used in combination with trastuzumab to further improve treatment outcomes.

In addition to targeted therapy, patients with HER2 positive breast cancer may also receive chemotherapy and hormone therapy, depending on the specific characteristics of the tumor. The use of these treatments aims to reduce the risk of recurrence and improve overall survival.

Diagnosing HER2 positive breast cancer involves similar methods as HER2 negative breast cancer, including imaging tests and a biopsy. However, additional testing is performed to determine the HER2 status of the tumor, such as immunohistochemistry (IHC) or fluorescence in situ hybridization (FISH).

It is important to note that advancements in targeted therapies have significantly improved the prognosis for patients with HER2 positive breast cancer in recent years. With the right treatment approach, many patients can achieve long-term remission and improved quality of life.

Conclusion

In conclusion, understanding the attributes of HER2 negative and HER2 positive breast cancer is crucial in guiding treatment decisions and predicting patient outcomes. While HER2 negative breast cancer is generally associated with a better prognosis and may have different treatment options, HER2 positive breast cancer requires targeted therapies to inhibit the overexpression of the HER2 protein and improve treatment outcomes. Early detection, accurate diagnosis, and personalized treatment plans are essential in providing the best possible care for patients with either type of breast cancer.