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
For 1, Good For 2, Good
For 3, Good For 4, Good
For 5, Good For 6, Good
For 7, Good For 8, Good
For 9, Good For 10 (Genetics
Quiz), Good For 11, Good
For 12, Good For 13, Good
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
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
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
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.
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
8:15 - Opening Ceremonies (Optional)
9:00 - 5K Run / Race
9:05 - 1 Mile Family Walk (**The Marrs Family be at this
9:15 - 5 K Non-Competitive Run / Walk
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
LAST name followed
by first initial or first name:
many women are
diagnosed with breast cancer in an average year?
2. What are three risk factors associated with development of breast
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. *****************************************************************