HER2+ Breast Cancer

Studies show that approximately 25% of breast cancer patients have tumors that are HER2+. HER2 stands for Human Epidermal growth factor Receptor 2. It is very important to find out your cancer’s HER2 status. This is because HER2+ tumors tend to grow and spread more quickly than tumors that are not HER2+. In addition, the treatment of HER2+ breast cancer is different than the treatment of breast cancer that is not HER2+. Women who are uncertain of their cancer’s HER2 status should talk to their doctor.

HER2+ breast cancer is aggressive, so it is important to find out your cancer’s HER2 status.^1-3 This can help your doctor choose which treatments may be right for you.

How is HER2 positive breast cancer different?

HER2 stands for Human Epidermal growth factor Receptor 2. Each normal breast cell contains copies of the HER2 gene, which helps normal cells grow. The HER2 gene is found in the DNA of a cell, and this gene contains the information for making the HER2 protein. ⁴

The HER2 protein, also called the HER2 receptor, is found on the surface of some normal cells in the body. In normal cells, HER2 proteins help send growth signals from outside the cell to the inside of the cell. These signals tell the cell to grow and divide. ⁴

In HER2+ breast cancer, the cancer cells have an abnormally high number of HER2 genes per cell. When this happens, too much HER2 protein appears on the surface of these cancer cells. This is called HER2 protein overexpression. Too much HER2 protein is thought to cause cancer cells to grow and divide more quickly. This is why HER2+ breast cancer is considered aggressive. ^1-3

HER2+ breast cancer is aggressive, so it is important to find out your cancer’s HER2 status.^1-3 This can help your doctor choose which treatments may be right for you.

Higher risk of breast cancer returning (recurrence)

• Women with HER2+ breast cancer:
• May be less likely to respond to certain breast cancer treatments
• May be more likely to have a recurrence (return) of their cancer

Women who are uncertain of their cancer’s HER2 status should talk to their doctor.

Inheriting the HER2 gene

Your tumor’s HER2 status is not hereditary. This means that HER2 status is not passed down from your parents, and you can’t pass it on to your children. However, there is a relationship between the genes in a person’s DNA and breast cancer in general. Ask your doctor for more information about the relationship between genes and breast cancer. ⁴

HER2/neu-positive, HER2-overexpressing, and HER2+ breast cancer

HER2/neu is another name for HER2, which stands for Human Epidermal growth factor Receptor 2. HER2-overexpressing means there is too much HER2 protein/receptor on the surface of the cancer cells. HER2/neu-positive breast cancer and HER2-overexpressing breast cancer are exactly the same as HER2+ breast cancer. ⁴

Who is Herceptin for?

Herceptin is approved for the adjuvant treatment of HER2-overexpressing, node-positive or node-negative (ER/PR-negative or with one high-risk feature)^† breast cancer. Herceptin can be used several different ways:

• As part of a treatment regimen including doxorubicin, cyclophosphamide, and either paclitaxel or docetaxel
• With docetaxel and carboplatin
• As a single agent following multi-modality anthracycline-based therapy

Herceptin in combination with paclitaxel is approved for the first-line treatment of HER2-overexpressing metastatic breast cancer. Herceptin as a single agent is approved for treatment of HER2-overexpressing breast cancer in patients who have received one or more chemotherapy regimens for metastatic disease.

† High-risk is defined as ER/PR positive with one of the following features: tumor size >2 cm, age <35 years, or tumor grade 2 or 3.

What important safety information should I know about Herceptin?

Herceptin treatment can result in heart problems, including those without symptoms (reduced heart function) and those with symptoms (congestive heart failure). The risk and seriousness of these heart problems were highest in people who received both Herceptin and a certain type of chemotherapy (anthracycline). Your doctor will stop or strongly consider stopping Herceptin if you have a significant drop in your heart function.

You should be monitored for decreased heart function before your first dose of Herceptin, and frequently during the time you are receiving Herceptin and after your last dose of Herceptin. If you must permanently or temporarily stop Herceptin due to heart problems, you should be monitored more frequently. In one study with Herceptin and certain types of chemotherapy, an inadequate blood supply to the heart occurred.

Some patients have had serious infusion reactions and lung problems; fatal infusion reactions have been reported. In most cases, these reactions occurred during or within 24 hours of receiving Herceptin. Your Herceptin infusion should be temporarily stopped if you have shortness of breath or very low blood pressure. Your doctor will monitor you until these symptoms go away. If you have a severe allergic reaction, swelling, lung problems, inflammation of the lung, or severe shortness of breath, your doctor may need to completely stop your Herceptin treatment.

Worsening of low white blood cell counts associated with chemotherapy has also occurred.

Herceptin can cause low amniotic fluid levels and harm to the fetus when taken by a pregnant woman.

The most common side effects associated with Herceptin were fever, nausea, vomiting, infusion reactions, diarrhea, infections, increased cough, headache, fatigue, shortness of breath, rash, low white and red blood cells, and muscle pain.

Because everyone is different, it is not possible to predict what side effects any one person will have. If you have questions or concerns about side effects, talk to your doctor.

Please see the Herceptin full Prescribing Information including Boxed WARNINGS and additional important safety information.

• References:
• 1. Slamon DJ, Godolphin W, Jones LA, etal. Studies of the HER-2/neu Proto-oncogene in human breast and ovarian cancer. Science. 1989; 244:707-712.
• 2. Slamon DJ, Clark GM, Wong SG, Levin WJ, Ullrich A, McGuire WL. Human breast cancer: correlation of relapse and survival with amplification of the HER-2/neuoncogene. Science. 1987; 235: 177-182.
• 3. Paik S, Hazan R, Fisher ER, etal. Pathologic findings from the national surgical adjuvant breast and bowel project: prognostic significance of erbB-2 protein overexpression in primary breast cancer. J Clin Oncol. 1990; 8:103-112.
• 4. Pegram M, Slamon D. Biological rationale for HER2/neu(c-erbB2) as a target for monoclonal antibody therapy. Semin Oncol. 2000; 27 (suppl9): 13-19.

Source: http://www.herceptin.com/her2-breast-cancer/testing-education/what-is.jsp