Herceptin: What is it?
Herceptin is a new drug to treat breast cancer that has spread
beyond the breast, among other things. Herceptin is the latest
genetic engineered medication.
Herceptin works by interfering with a gene that contributes to an
especially aggressive form of breast cancer in some women. This
gene is called the HER2 gene. About a quarter to a third of women
with breast cancer have this gene several times in their cells. The
gene produces biological factors that cause cells to divide.
Normally, cells divide everyday. But, cancer is the unusual,
abnormal division of cells. It is a division pattern that is out of
control and that encroaches on and destroys organs and their
ability to function. When several copies of this gene that promotes
cell division are present, it promotes abnormally fast growth rates...
rates which lead to the development of cancer.
Herceptin interferes with this process. It seeks out the offending
cell dividing stimulating substances that are produced by the
HER2 gene and are found on the surface of cancer cells. It binds to
them, and blocks their action.
Herceptin could benefit breast cancer patients in more ways than
one. Not only does it hold the promise of halting but breast cancer,
but it does it without the horrific side effects of traditional cancer
drugs. Past generations of cancer drugs simply worked by
attacking any rapidly dividing cell. This attacked the cancer cell,
but also did a number on the stomach and caused hair to fall out.
They also caused mouth sores and immunity to plummet.
Herceptin does none of this. Fever and chills are the most
common side effect so far. Also, it works on breast cancer that has
spread, which is much more deadly than when it is limited to the
breast. To date, the effective treatments for this are few and far
What is still being worked out through research is how to integrate
Herceptin with existing treatments, how long to use it, and
quantifying how well it works. A recent study looked at women who
took Herceptin only to treat their breast cancer. Sixteen percent
had slowed progression, 4% had complete remission, and 12 had
partial remission. A total of 32% had improvement.
Another study looked at Herceptin combined with older treatments
compared to the older treatments alone was even better. The
percentage of women who had progression of their cancers stop
went from 10% to 25%. The time it took to progress went from 4.6
to 7.6 months. The percentage who had a partial response went
from 32% to 48%.
While that may be far from a cure, it is a tremendous improvement
from the past. Before these types of breast cancer were quickly
and uniformly fatal, with poor quality of life due to the side effects of