The ability to identify a woman
with a germ-line mutation in
BRCA1 or BRCA2, through
clinical genetic testing, allows that
woman's physician to implement preventive
strategies that may spare her
from developing breast or ovarian
cancer. Unfortunately, the most effective
strategies currently are also the
most drastic; namely, prophylactic
mastectomy and/or prophylactic
oophorectomy.
That high-risk women would even
consider prophylactic surgery is directly
related to their high likelihood
of developing cancer. While the lifetime
risk of breast cancer in the general
population is 13.4%, in a BRCA1 mutation
carrier, it ranges from 50% to
80%.[1-4] Similarly, the lifetime risk
of ovarian cancer in the general population
is 1.7%, and in BRCA1 mutation
carriers, it is 20% to 40%.[1-4]
For BRCA2 mutation carriers, the estimates
for breast and ovarian cancer
risk remain substantially above those
of the general population but slightly
lower than those for BRCA1 mutation
carriers.[2-4]
Importance of Genetic
Counseling/Testing
For physicians who manage highrisk
women, the importance of genetic
counseling and genetic testing
cannot be overemphasized. Clinical
genetic testing allows a substantially
more precise estimate of a woman's
risk of breast and/or ovarian cancer
than family history alone. Women who
test positive for a deleterious BRCA1
or BRCA2 mutation need appropriately
aggressive management for the
prevention and/or early detection of
breast and ovarian cancer. Women
who test negative for a known deleterious
mutation in their family ("true
negatives") can be reassured that they
are not at increased risk of breast and/
or ovarian cancer, despite the substantial
family history.
Consider a parent with a known
BRCA mutation: Each child has a
50/50 chance of inheriting the mutation.
By relying on family history
alone, our ability to assess each individual's
risk is limited. Recommending
such procedures as prophylactic
mastectomy for an unaffected individual
based on family history alone
is problematic.
In their article, Levine and Gemignani
define the patients who should
be considered for genetic counseling.
Medical and gynecologic oncologists
play a key role in selecting women
who should be referred for genetic
counseling. Genetic counselors are
trained in creating family cancer pedigrees,
in identifying possible genetic
syndromes, and in discussing the pros
and cons of genetic testing. Not all
patients who are referred for genetic
counseling are recommended for genetic
testing. In general, genetic testing
is most beneficial when the
following two criteria are met: First,
the testing is performed on an affected
family member, ie, someone who
has a personal history of cancer, and
second, the pedigree is at least mildly
to moderately suggestive of a hereditary
breast ovarian cancer syndrome.
Communication between the
genetic counselor and medical/gynecologic
oncologist is crucial. The
knowledge that one carries a BRCA1
or BRCA2 mutation not only has an
impact on unaffected family members,
but can also affect the management of
the patient with the newly diagnosed
cancer. For example, in a young woman
with breast cancer and a substantial
family history of premenopausal breast
cancer, identification of a BRCA1 mutation
may affect the decision to undergo
a bilateral mastectomy rather
than a unilateral mastectomy.
The decision to undergo genetic
testing should be made after appropriate
counseling about the benefits
and limitations of the tests. Certainly,
many moderate-risk women will undergo
testing and receive inconclusive
test results. In addition, a number
of women will choose to undergo prophylactic
oophorectomy without
pursuing genetic testing first. However,
providing an accurate assessment
of an individual's cancer risk
allows the physician to better counsel
the patient as to the risks and benefits
of prophylactic surgery, as well as the
alternatives.
Prophylactic Surgery in the
Management of High-Risk Women
As reviewed in the paper by Levine
and Gemignani, prophylactic
mastectomy and prophylactic salpingo-
oophorectomy confer substantial
protection against the development of
breast and ovarian cancer in truly highrisk
patients.[5-7] Besides surgical
prophylaxis, current options to
decrease the risk of ovarian cancer
are limited. Although oral contraceptives
have been shown to decrease the
risk of ovarian cancer in the general
population, conflicting reports have
emerged regarding the efficacy of
oral contraceptives in high-risk women.[
8,9] Furthermore, one study
showed a slight increased risk of breast
cancer among BRCA1 mutation
carriers under age 30 who use oral
contraceptives.[10]
Given that there are no effective
screening strategies for ovarian cancer,
prophylactic salpingo-oophorectomy
is a reasonable option for
high-risk women who have completed
childbearing. An additional benefit
of prophylactic salpingo- oophorectomy
is a decrease in the risk of breast
cancer by approximately 50% among
BRCA1 and BRCA2 mutation carriers.[11]
The operative procedure
should include total removal of the
ovaries and fallopian tubes, and the
pathologic assessment should include
a full histologic examination of the
specimens to rule out occult tumors.[
12,13] The long-term medical
effects of surgical menopause and its
effect on quality of life have not been
adequately studied.
A BRCA1 or BRCA2 mutation often
is identified after a diagnosis of
breast cancer. In high-risk women,
prophylactic mastectomy of the contralateral
breast has been shown to
decrease risk of a second primary.[14]
Even in unaffected women with
BRCA1 or BRCA2 mutations, prophylactic
mastectomy has become an
acceptable option for the prevention
of breast cancer.[15] Immediate breast
reconstruction is often performed.
Conclusions
Although there is hope that new
chemopreventive and screening strategies
will be discovered, prophylactic
surgery will likely remain an option
for the prevention of breast and ovarian
cancer in BRCA1 and BRCA2
mutation carriers. Women with a
suspicious family history should be
identified and referred for genetic
counseling, and appropriate patients
should be offered genetic testing.
Women who are found to be mutation
carriers should be offered a coordinated
plan for the prevention of breast
and ovarian cancer. Many of these
patients have had firsthand experience
with breast or ovarian cancer via a
relative who was diagnosed and treated.
Although the decision to undergo
prophylactic surgery cannot be made
lightly, the ability to prevent cancer
in these high-risk individuals represents
a positive step forward.
