Reducing the burden of cancer is important to women who have a
mutation in the BReast CAncer
susceptibility genes BRCA1 or BRCA2. It is estimated that 50-85%
of these women will develop breast cancer by age 70; many will develop
breast cancer before age 50. Women who have a BRCA mutation also
have an increased risk of ovarian cancer. BRCA1 mutation carriers
have a 40% chance of developing ovarian by age 70. Women with a
BRCA2 mutation have about half this risk.
Breast Cancer Screening and Prevention
Ovarian Cancer Screening and Prevention
- Surveillance for ovarian cancer is recommended to
begin at age 35 (or five to ten before the earliest age at which
an ovarian cancer has been diagnosed in the family). Current
recommendations for ovarian cancer screening of women at high
genetic risk include:
- Pelvic examination once or twice a year.
- A transvaginal ultrasound and CA-125
blood test every 6-12
months, starting at age 35, or 5 to 10 years earlier than the
earliest age of first ovarian cancer diagnosis in the family.
Note that the effectiveness of this screening schedule has
not been proven.
There are also medical and surgical approaches to reducing the
risk of ovarian cancer in high-risk women:
- Surgical prevention is called risk-reducing (or “prophylactic”)
salpingo-oophorectomy (RRSO). This involves removal of the
ovaries and fallopian tubes before there is clinical evidence
that cancer has developed. It has been estimated that this
procedure results in a 95% reduction in the risk of ovarian
cancer in women who carry a mutation. It is recommended that
high-risk women consider this procedure when they complete
their childbearing. Surgical removal of the ovaries from a
woman who is still regularly having her periods results in
loss of fertility and menopausal symptoms, such as hot flashes.
The risks and benefits of menopausal hormone therapy for women
who have undergone RRSO have not been clearly defined in women
with a BRCA mutation. Tubal ligation (“tying
the tubes”) may also help reduce the risk of ovarian
cancer without removing the ovaries. It does not reduce cancer
risk as much as RRSO does, but it avoids immediate menopause.
The Premature Menopause Pamphlet, Health Care Maintenance for
Women Undergoing Risk-Reducing Ovarian Surgery provides useful
information for women who have undergone RRSO, as well
as for their health care providers.
- Tubal ligation (“tying the tubes”) may also
help reduce the risk of ovarian cancer without removing the
ovaries. It does not reduce cancer risk as much as RRSO does,
but it avoids immediate menopause.
- Medical prevention is for women who do not want or
are not yet ready to have surgery to remove their ovaries. The
use of oral contraceptives (birth control pills) has been shown
to reduce the risk of ovarian cancer by about 50% among women
in the general population, but information about the potential
risks and benefits of oral contraceptives among BRCA1/2 mutation
carriers is limited. While the risk of ovarian cancer may be
reduced, the risk of breast cancer may be increased with oral
contraceptive use in high-risk women.
Imaging of the Breast:
Mammography and breast magnetic resonance imaging (MRI) are currently
the best available tools for detecting early breast cancer. Mammography
may fail to detect some breast cancers. Importantly, mammography
may miss some breast cancers in younger women. This is of concern
because much of the BRCA1- and BRCA2-related breast cancer occurs
before age 50. In postmenopausal women, it is easier to detect
a cancer by mammography, which appears as a white mass, or associated
with white calcium spots, contrasted against a dark background.
Before menopause, a woman's breasts are made up of relatively more
supporting tissue (which appears "dense" or white on
a mammogram) and less fatty tissue (which appears "radiolucent" or
||The picture on the left is a mammogram of a woman
with a breast lump. The location of the breast lump is indicated
by the white dot on the mammogram. The mammogram failed to
show the large breast cancer (indicated with the arrow), which
was clearly seen on the MRI study of the breast (picture on
Computer-assisted mammography reading and digital mammography are now being
studied as ways to improve the accuracy of mammography interpretation. Annual
breast MRI, an imaging technique that does not involve radiation exposure,
is now routinely recommended as a way to improve detection of early breast
cancers when screening women at high genetic risk of breast cancer
Sampling Breast Duct Cells:
Over 95% of breast cancers develop from the cells
that line the breast milk ducts.
There has been much interest in looking for ways
to screen breast duct cells for early, pre-cancerous changes. Evaluating
the breast in this way is still very much a research tool. While
this approach may have promise, the benefit of this type of screening
has not been proven. Breast
duct lavage, in which cells are washed
from the breast duct, nipple
aspiration, which uses gentle suction
to collect fluid from the nipple, and needle
biopsy of the breast,
are examples of techniques used to obtain breast duct cells and
fluid for research purposes.
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information about breast
cancer and gene