The Genetics of Breast Cancer
You've probably heard that the risk of any woman developing breast cancer
is 1 in 10 by the time she is 80 years old. But for 5 to 10 percent of women
who get breast cancer, this risk is much higher (up to 85 percent over a
lifetime). The risk is higher for this small group of women because they are
born with an inherited change (mutation) in a cancer-causing gene that
makes them more likely to develop breast cancer.
As you read this information about breast cancer, please keep in mind that
only 5 to 10 percent of all breast cancer is hereditary.
Genes are found on our
chromosomes. You
received half of your
chromosomes from
your mother and the
other half from your
father. Each
chromosome is
composed of hundreds
to thousands of genes.
Genes are the
instructions that make
us who we are. Each
gene is composed of a
series of amino acids
that must be linked
together in a particular
order to make a specific
protein that has a
specific function in
your body.
diseases, such as heart
disease, diabetes or
cancer.
Genes also tell your
body which proteins to
make to meet your
body's needs and when
to stop making proteins
because you have
enough.
While there are many kinds of genes, we'll talk about two kinds that play a
significant role in triggering cancer: genes that encourage cell growth
(oncogenes) and genes that suppress or block tumor growth (tumor
suppressor genes). Oncogenes kick the cell's "grow" message into high
gear. When tumor suppressor genes don't do their jobs, they contribute to
cancer because they no longer act as "brakes" to turn off cell growth