What is Biology Good For?
Treating Breast Cancer: Herceptin

This assignment is optional. Read this essay and answer the questions at the bottom for 3 extra credit points. It is not necessary to visit the links in the text unless you are interested in more information.)

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On September 25, 1998 the U.S. Food and Drug Administration (FDA) approved Herceptin as a biologic approach for the treatment of metastatic breast cancer (cancer that has spread beyond the breast and lymph nodes under the arm). This approval was the result of over 15 years of scientific investigation and clinical testing that was done at Genentech, the UCLA Medical Center, and other labs around the world.

What is Herceptin?

Herceptin (generic name trastuzumab) is a monoclonal antibody that has been genetically engineered to bind to a specific protein called HER2 (or the HER2/neu protein), a protein receptor over-expressed on the surface of some breast cancer cells. Herceptin binds only to cells expressing the HER2 protein on the cell surface. Once bound to the cells, Herceptin slows the growth and spread of these tumors.

What is HER2?

HER2 (Human Epidermal growth factor Receptor 2) is a protein found on the surface of cells that plays a key role in regulating cell growth. When the HER2 gene is altered, extra HER2 proteins may be produced. This over-expression of HER2 causes increased cell growth and reproduction, often resulting in more aggressive tumor cells. Appromimately 25-30% of breast cancers over-express HER2 (produce excess amounts of HER2).

Does Herceptin work for all breast cancers?

No. Herceptin is very effective in the treatment of HER2-positive breast cancer, but HER2 protein over-expression affects only 25% to 30% of breast cancer patients. However, a tumor with HER2 over-expression is very aggressive in its ability to grow and metastisize, and as such, these tumors are often not responsive to standard breast cancer treatments like chemotherapy. Herceptin is used to control the spread of these particularly agressive HER2-overexpressing tumors that have not responded to traditional chemotherapy.

Pathologists test tumor tissue for HER2 over-expression at the time of breast biopsy or surgery, or on stored tumor tissue from previous biopsy. To test for HER2 over-expression, the tumor tissue is stained by a specific solution. Depending on the level of staining, the tumor tissue sample may be classified as HER2 positive. If the tumor cells should test positive for HER2 overexpression, Herceptin treatment is considered. Today, over 200,000 HER2 diagnostic tests are performed per year.

In clinical studies, Herceptin slowed the growth of tumors and in some cases, made tumors disappear altogether! On average, Herceptin by itself results in a 14% reduction of tumor size. Tumors disappeared completely in some patients (3%) who had disease limited to skin and lymph nodes! In combination with the chemotherapy drug Taxol, women who received Herceptin with chemotherapy had tumors were that reduced by 50% or more in size compared to chemotherapy alone. The one-year survival rate for women who received herceptin with chemotherapy was 79% compared to a survival rate of 68% for chemotherapy alone.

What are the risks of Herceptin?

Herceptin can cause weakening of the heart muscle, resulting in congestive heart failure. Heart damage is more common when Herceptin is used in combination with the chemotherapeutic drugs anthracycline and cyclophosphamide (AC). Therefore, Herceptin is not approved for use with AC regimens. Heart function should be checked before starting treatment, and monitored during treatment. If heart problems are detected, Herceptin therapy may be discontinued.

What are the side effects of Herceptin?

Typically, Herceptin is administered intravenously (through the vein) in an outpatient clinic setting. In combination with chemotherapy, Herceptin increases the frequency of the following chemotherapy-associated side effects:

Side effects of Herceptin are most common with the first dose. With subsequent doses, side effects are less likely. Side effects are treatable.

References for this Good For:
Genentech Inc., Herceptin backgrounder. The site is divided into separate sections for patients and health care professionals.Lots of breast cancer resources. Imaginis: Breast Cancer
A great book!!: Her-2: The Making of Herceptin, A Revolutionary Treatment for Breast Cancer. Written by Robert Bazell, the scientific correspondent for NBC News, and an excellent science writer for the layperson or scientist. "This book chronicles the dramatic discoveries, strong personalities, scientific investigation, money, politics, ego, corporate decisions, patient activism, and luck involved in getting Herceptin from the lab to the market." (Now out of print, but get out your library card and put a hold on it at the IMCPL if you are interested).

 

IUPUI Race for the Cure - Saturday, April 21 - Team IUPUI Registration
Do you have an Aunt, Mother, Grandmother, Sister, or Friend who is a breast cancer survivor (or whose life has been lost to breast cancer)? The annual IUPUI Race for the Cure raises money for Breast Cancer Research. The race is Saturday, April 21. Cost is $18 per person (includes T-shirt and lots of other goodies donated by area businesses). Print out the on-line registration form, and call Kim Burrows (SL314, School of Science 274-0579) or Kelly Young (Community Outreach Director, 274-7711) to deliver your registration and payment. Hope to see you there!!!!!

8:15 - Opening Ceremonies (Optional)
9:00 - 5K Run / Race
9:05 - 1 Mile Family Walk (**The Marrs Family be at this one!**)
9:15 - 5 K Non-Competitive Run / Walk

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Questions: 3 points extra credit. Click on the links for more information! One sentence should be enough to answer each question . Once you hit 'submit', you will receive a Thank You confirmation page.

Please type your Student ID Number:
LAST name followed by first initial or first name:

1. How many women are diagnosed with breast cancer in an average year?
2. What are three risk factors associated with development of breast cancer?
3. Why isn't Herceptin used to treat all breast cancers?

You may change your mind as often as you wish. When you are satisfied with your responses click the SUBMIT button. You will receive a "THANK YOU" page as a confirmation that your response has been sent to me. *****************************************************************