Most breast cancer (65-70%) occurs in women over
50 years of age. Only 1 in 2500 women develop breast
cancer by age 30 and only 1 in 200 women develop it
by age 40. Younger women who develop breast cancer
are more likely to have genetic risk factors. It is
almost as if there are two different types of breast
cancer, that occurring rarely, but before menopause
and that occurring more commonly, but after menopause.
A recent article, Vogel VG: Breast cancer in younger
women: Assessment and risk management. The Female
Patient 1999;24:81-86, looks at risk factors and what
can be done to prevent breast cancer if a woman is
at greatly increased risk for breast cancer.
Is it normal to be extremely anxious about the possibility
of developing breast cancer?
It is normal to be concerned about developing breast
cancer because this is a common (one in 9-11 lifetime
risk) cancer. However it is unhealthy to be overly
concerned about it. Many women develop a significant
degree of anxiety about possible cancer because they
overestimate their chance of getting it. Some studies
show that women overestimate their annual chance of
getting breast cancer by 20-60 fold. In fact some
women who are at increased risk for breast cancer
experience as much stress and anxiety as women actually
diagnosed with invasive breast cancer.
The best remedy to this excessive concern is to know
exactly what your specific risk rate is.
How can I tell if I'm at increased risk for breast
cancer?
Keep in mind that most factors that have been associated
with an increased incidence of breast cancer are just
that -- associations -- they are not necessarily cause
and effect. In other words, women who have these "associated"
risks may actually use or be exposed to other agents
or factors that are the causative or promoter agents.
Why not just start mammograms at a much earlier age,
say in the 30's to pick up cancer earlier?
Two reasons are usually cited for not just starting
mammograms earlier:
There are risks, complications, and discomforts due
to early and regular mammograms
Reductions in death and morbidity due to breast cancer
have not been shown to be worth the costs of mammogram
screening on a regular basis in women under 40
The disadvantages of routine mammograms at a younger
age include more years of radiation exposure to the
breast which may in turn promote a breast cancer,
physical pain from the breast compression during mammography,
the increased anxiety and unnecessary testing due
to many false positives (see Risk of False Alarm for
Breast Cancer), potential over treatment of diagnosed
lesions that are not life threatening, false reassurance
from negative studies that just happened to miss lesions
because they were too small or the breasts were too
dense to see them, and simply the anxiety naturally
occurring between scheduling the screening procedure
and receiving the results.
If I have a strong family history of breast cancer
should I get genetic testing?
If you have any relative who has had breast cancer
and is still alive, that person should be encouraged
to ask their doctor if they (not you) can undergo
genetic testing for known breast cancer associated
genes. Then if they have positive tests for genetically
linked breast cancer, you should have genetic counselling
and possibly testing.
If you have more than one first-degree relative (mother,
sister, daughter) with breast cancer, any female relatives
who developed breast cancer before menopause or age
50 or had both breasts involved, or any male relative
who developed breast cancer, then you need to see
a genetic counselor for advice about testing.
If I am at very high risk for breast cancer, can
I do anything to prevent it or lower my risk?
The most commonly used medicine to prevent breast
cancer recurrence or even to prevent the occurrence
of a new breast cancer is tamoxifen. It is effective
at reducing by about 50% the incidence of a new breast
cancer. It can have significant side effects and complications
so it is only used for women who are at high risk
for breast cancer. Side effects and complications
include:
increased endometrial cancer
increased heart attacks and strokes
increased blood clots
side effects from low estrogen blood levels such as
vaginal dryness, hot flashes, more frequent urinary
tract infections, and pain with sexual relations
There are some women, however, whose risk is so high
for breast cancer development that they need to consider
taking tamoxifen for prevention and risk the tamoxifen
side-effects and complications. These include:
a history of lobular carcinoma in situ (not invasive,
just confined to the upper skin layer) by previous
biopsy
a history of ductal carcinoma in situ by previous
biopsy
a history of atypical ductal/lobular hyperplasia by
previous biopsy
known genetic mutations, BRCA1, BRCA2 and others,
by genetic testing
a premenopausal woman with a 5 year probability of
breast cancer of more than 1.7% as determined by multivariate
risk prediction models
I have heard that some women who are at very high
risk for breast cancer actually have surgery to remove
the breasts in order to prevent cancer. Is that true?
Yes, it is true, but there are very few indications
for having a "prophylactic breast removal (mastectomy)."
It is better for women at high risk for breast cancer
to take tamoxifen and be under very close medical
surveillance with exams and imaging studies than to
undergo breast removal just to prevent breast cancer.
While some women who have undergone prophylactic mastectomy
report significant emotional relief, it is important
to remember that bilateral mastectomies only prevent
90% of subsequent invasive breast cancers.
The following women might consider prophylactic mastectomy:
those unwilling to consider tamoxifen therapy for
primary prevention
those who have been shown to be genetic carriers for
breast cancer predisposing genes
in the absence of genetic testing, those who have
a family history suggesting a genetic syndrome such
as bilateral disease, premenopausal breast cancer
in one or more first-degree relatives, or multiple
affected relatives in several generations
women with a high risk score or a lifetime risk of
breast cancer over 20%
women with a family history of breast cancer in a
first-degree relative plus a breast biopsy showing
atypical hyperplasia or in situ lobular or intraductal
cancer
those with an increased objective risk plus repeated
breast biopsies with significant scarring resulting
in difficult physical exams or mammogram examinations
showing multiple nodular densities
women with almost a major psychological disability
due to extreme fear of cancer
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