There has been an explosion of information about the genetic basis for
breast cancer, both in the scientific literature as well as in the
media. Women are confronted each month with magazine headlines asking,
"Do you have a breast cancer gene?" Increased information is now
available about inherited breast cancer .The issues are complicated and
include:

• The genes involved
• Who should be tested
• What can be done if the test is positive

What Is Known About Hereditary Breast Cancer?
Women in the United States have a one in eight risk of developing breast
cancer at some time in their life. A smaller number of women (5-10
percent), have a greater risk to inherit a defective breast cancer gene.
The first gene, of this type, which plays a role in inherited breast
(and ovarian) cancer is called BRCA1. It was first identified in 1990. A
second gene, BRCA2, has also been discovered. Approximately 1 in 500 to
1 in 800 women carry a BRCA1 mutation. Some ethnic groups may have a
much higher rate of BRCA1 abnormality. Women with an abnormal form of
the BRCA1 gene (a mutation) have up to an 86 percent lifetime risk of
breast cancer and up to 50 percent risk of ovarian cancer.

The degree of risk for women with BRCA2 mutations is similar. The breast
cancers in these women often occur at an earlier age than for women
without the mutations (20 years earlier on the average). Both breasts
are often affected. Breast cancer is unusual in men, but a father may
carry a BRCA1 or BRCA2 mutation and pass them on to his children.

One difficulty in testing for BRCA mutations is that over 100 different
alterations have been identified in the BRCA1 gene alone .The testing
required to detect any of the many potential mutations is quite
laborious and expensive.

What Should You Know About Genetic Testing for Breast Cancer?
Less than 10 percent of all breast cancers are caused by a mutated BRCA
gene, so most women do not need to be concerned about having a "cancer
gene". A woman might be a candidate for genetic risk assessment,
testing, and counseling if one or more of the following criteria are
present:

• A woman has two or more first degree relatives (mother, sisters) who have been diagnosed with breast (or ovarian) cancer
• The cancer was diagnosed at an earlier than usual age (generally, younger than 50 years of age) for breast cancer
• A relative had bilateral(both sides) breast cancer
• Breast (or ovarian) cancer appears in more than three generations of the family

It is important to emphasize that just because breast cancer has
occurred in a family, it does not necessarily mean it is inherited. Both
sides of a woman's family should be examined, not just her mother's
side. The mutated gene may be passed down on the father's side of the
family, as well as, the mother's.

Testing for mutated cancer-associated genes is still a very new
technology and it has some limitations. The test results are not always
100 percent interpretable (easy to explain). The test may indicate a
mutation that has not previously been seen, therefore, the actual
meaning of the mutation is not known.

A number of ethical, legal, and psychological implications are
associated with genetic testing. All of these implications should be
seriously discussed and considered before deciding to begin genetic
testing. The question always remains-"What actions should be taken if a
mutated gene is identified?"

The issue of genetic testing is far more complex than obtaining a simple
blood test. Always follow a detailed process of assessment, evaluation
and counseling with a trained professional before beginning the actual
genetic testing. Never take BRCA testing lightly.

What Are the Treatment Options for Women with BRCA Mutations?
Cancer management has always emphasized the treatment of cancer after it
has been diagnosed. The idea of cancer prevention, however, provides
some encouraging options for the breast patient. Only high- risk
patients were offered hormone blockers or surgery to prevent breast
cancer. Prophylactic (preventive) mastectomies were sometimes performed
in high-risk patients, but four out of five patients undergoing this
form of surgery would never have developed cancer anyway. The
identification of a subgroup of patients found to be BRCA positive now
enables the physician to direct treatment options towards patients who
have an 86 percent chance of developing breast cancer and a 50 percent
chance of developing ovarian cancer during their lifetime. A recent
article in the New England Journal of Medicine (May 15, 1997) found that
a prophylactic mastectomy could significantly increase life expectancy
in women with BRCA mutations.

Recently, the results of the Breast Cancer Prevention Trial have shown
that Tamoxifen may be effective in reducing the risk of breast cancer in
high- risk women (i.e. women with a significant family history of breast
cancer). This information adds a new and important tool for the
treatment of patients at significant risk of breast cancer

There are no current uniform standards for managing high-risk patients.
The increased understanding of tumor biology and patient outcomes should
offer some reasonable decision-making patterns for the future. A
bilateral (both sides) mastectomy with reconstruction becomes a very
real option if a patient can be assured that she will develop breast
cancer in her lifetime. Waiting until the cancer is diagnosed is far
more risky and expensive. A pill that blocks female hormones (Tamoxifen)
may lower the overall risk of cancer and can serve as an effective form
of prevention in some patients.

Women who do not carry a BRCA gene still remain at the general
population's standard risk of one in eight. Routine follow-up
appointments are more appropriate treatment in these patients than
surgery.

Prevention of ovarian cancers is slightly more complicated. Removal of
the ovaries prevents only about 85 percent of these cancers. The optimal
treatment of these patients is still in a stage of evolution.

The new ability to specifically target those patients at high-risk to
develop breast cancer is an exciting breakthrough in the area of
preventive cancer management.