Herceptin®
Herceptin is a new anti-cancer drug just approved in the US in the fall
of 1998 for use against certain types of breast cancer. It is the
first of a new type of treatment; a genetically engineered, man-made cancer
anti-body. As such it is not a chemotherapy and does not have the
side effects of chemotherapy. The catch is that it only works for
patients whose cancer cells are HER2/neu positive. This mouthful
means that it only works if the patient’s cancer has an excess of a specific
protein present on its surface. Apparently about 20% of breast cancer
is HER2/neu positive. The Herceptin anti-body, once injected into
the blood stream, attaches itself to the cancer cells that are HER2/neu
positive and once attached, the bodies normal immune system recognizes
the cancer cells as bad and goes after them. Basically the attached man
made anti-body marks the cancer cells for destruction in the same way that
our own naturally produced anti-bodies do for infections. This is
great because one typically does not naturally produce anti-bodies to breast
cancer as the cells are too similar to normal cells. To determine
if one is HER2/neu positive, one needs to have a pathology test done on
a sample of cancerous tissue such as that removed during a lumpectomy (or
perhaps even a sample from a biopsy, if there is enough). The test
done is sometimes called a DAKO test as this is the name of the kit used
to do the test. HER2/neu testing is not generally available in Canada.
HER2/neu is also called c-erb B2. Apparently these are two different
scientific names for the gene sequence relating to this special protein
that is produced in excess. I obtained samples of Dulce's tumor that
had been removed a year before I found out about Herceptin. Tumor
samples are typically preserved in paraffin by the pathologists who examine
them after surgery. You can get them years later. Unfortunately,
in our case Dulce was HER2/neu negative and thus Herceptin was not an option.
But I personally know of patients with advanced metastatic breast cancer
where Herceptin produced amazing results. I would recommend that
every breast cancer patient investigate whether Herceptin is an option.
Kevin...
I had Dulce’s lumpectomy sample tested in Seattle by
Dr. Rodney Schmidt
Pathology Department
University of Washington Medical Center
Seattle, Washington
Tel: (206) 548-6400 Fax: (206) 548-4928
Dulce’s oncologist in Seattle was:
Dr. Julie Gralow
Oncology Department
University of Washington Medical Center
Seattle, Washington
Tel: (206) 543-9598 Fax: (206) 616-8553
Herceptin is produced by the company Genentech:
Tel: (650) 225-1000 Fax: (650) 225-6000
Web: www.genentech.com
www.genentech.com/pressrelease/1998/09_25_98.html