BREAST CANCER SCREENING and BREAST DENSITY Q & A:
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You Should Know About Breast Cancer.
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is breast density significant?
contain more glandular and connective tissue. Less dense
breasts are mainly made up of fat tissue. Every woman
has different amounts of the different types of tissue
in her breasts. Breast cancer itself is made up of dense
tissue. This means that on a mammogram, a tumor is
harder to spot in dense tissue than in fatty tissue,
because the tumor looks a lot like the tissue around it.
An analogy is often used to describe the way dense
tissue looks on film, "It's like looking for a polar
bear in a snow storm." Breast cancers are readily seen
in fatty tissue with up to 98% sensitivity in film
Dense breast tissue itself is a risk factor for breast
cancer, with the risk 4-6 fold higher in women with
extremely dense breasts compared to fatty breasts, and
breast cancer is more likely to develop in denser areas of
the breast. Extremely dense (>75% dense) or
heterogeneously dense (51-75% dense) is present
in over half of women younger than age 50 years and
one-third of women age 50 years and
often is cancer missed using standard film mammography, in
women with dense breasts?
film mammography, only 30-55% of breast cancers are
detected in women with dense breasts. That's why digital
mammography is so helpful. But regardless, mammography is
still an important piece of early detection. Please read
What is the prevalence of dense breast tissue in
to the American College of Radiology Imaging Network
(ACRIN), 40% of all women undergoing screening mammography
have dense breasts. Breasts tend to become less dense as
women get older, but some women continue to have dense
breast tissue throughout life. Over half of women younger
than 50 and one-third of women older than 50 have dense
do you know if you have dense breasts?
a mammogram can tell you for sure. Look for the terms
"heterogeneously dense or very dense", or "extremely dense"
in your mammogram report, which would indicate dense
Most mammography reports use the following terminology to
categorize and describe breast density: describing four
different categories: (1) entirely fat; (2) scattered
fibroglandular densities; (3) heterogeneously dense; and
(4) extremely dense. The BIRADS classifications (American
College of Radiology Breast Imaging Reporting and Data
System) are used as a part of a radiologist's mammographic
I have dense breasts; what do I do differently, if
depends on what you are doing now, but these are important
factors to consider in addition to nationally recommended
diligent with recommended monthly self breast exams and
yearly mammography and clinical exams.
• DO NOT skip a year with your annual mammogram. Have
prior exams sent to your current facility.
This will allow small changes to be seen.
is difficult if the previous year's film is not available.
• Go to a facility which specializes in breast
imaging, when possible, to make sure you have experts who
spend most of their time in this area.
• Go to a facility with digital mammography, when
possible, if you fit the guidelines (see below).
• Make sure you talk to your doctor about following up
any suspicious, palpable lump with further imaging.
• See a breast surgeon or surgeon specializing in this
area to follow up on suspicious areas, when unsure.
• Trust your intuition
• Ask for whole breast ultrasound screening if it is
offered at your facility and they have the equipment and
the expertise to do it.
is important about digital mammography and where can I have
a recent study with nearly 50,000 women participating, they
found that digital mammography was more sensitive than film
in finding cancers in women with dense breasts. Sensitivity
for women with dense breasts was only 55% for film and 70%
for digital, though these are in the most perfect research
conditions. Digital mammography allows the radiologist to
see images more clearly and to manipulate the image to see
it better (brightness, contrast, size, and orientation).
Digital mammography is becoming more widely available.
Because of it's popularity, you may need to request
your imaging facility. Still, choosing a facility with
specialization in breast imaging is the most important
the study say who would benefit most from digital
mammography was significantly better in screening women who
fit any of these three categories:
• Under age 50 (no matter density)
• Any age with heterogeneously (very dense) or
extremely dense breasts
• Pre- or perimenopausal women of any age (defined as
having last menstrual period within 12 months of mammogram)
was no benefit for women who fit ALL the following
• Over age 50
• Don’t have dense breasts
• Not menstruating
is ultrasound important?
be used to evaluate masses that are hard to see on a
mammogram. Especially for women with dense breasts,
ultrasound is helpful in characterizing lumps or other
areas of concern. The Avon/ACRIN 6666 Trial showed that
when added to a screening mammogram, among women who were
at increased risk of breast cancer and had dense breast
tissue, ultrasound increased detection.
effective is it?
has proven to increase the number of cancers detected by
67-100% in studies at single institutions. In addition,
smaller invasive cancers have been found with this
technology, usually before the cancer has spread to the
lymph nodes. For those at high risk for breast cancer who
are not recommended for MRI, it may improve detection of
breast cancer over mammography alone.
MRI is more sensitive and better for those at high
risk, but is costly
and insurance may not pay for it. Ultrasound is less
costly, doesn’t involve radiation, and may be easier
for many women to tolerate and obtain. Breast MRI’s
involve IV contrast being injected into the veins while
lying still for 30-60 minutes.
Why isn't ultrasound screening used instead of mammography?
still important for women with dense breasts because they
are good at showing calcifications which are sometimes
produced by early breast cancers.
Ultrasound is used to diagnostically evaluate areas of
concern, right now.
Screening ultrasound looks at the
entire breast the way screening mammography does now, but
is not routine in most clinics. Most technologists are not
trained in whole breast ultrasound screening and when done,
is a lengthy process. Technologists are mostly trained
screening, where they are looking at a single area of
use of screening ultrasound in high risk women has been
under investigation with the AVON/ACRIN 6666 trial with Dr.
Wendie Berg as the Principal Investigator. The first
results of the AVON/ACRIN 6666 trial showed that accuracy
in women with dense breasts was 78% with digital mammograhy
only, and 91% accuracy with mammograpy AND
Twenty eight percent more cancers were detected than with
With any test,
there is a risk of finding something that needs to be
biopsied but is not due to cancer. You may want to check
whether your insurance covers screening ultrasound.
About a third of
U.S. facilities offer screening ultrasound, so it is
reasonable to request it, if offered by your breast imaging
facility (if they have good equipment and the expertise to
Approximately 211,000 new diagnoses of breast cancer each
• Approximately 58,00 new diagnoses of non-invasive
• 40,000 women will die this year of breast cancer-one
every 13 minutes in the U.S.
• Every 2 minutes someone is diagnosed
• Majority of breast cancers occur in women over 50,
but women at any age can have breast
The number one risk
factor for breast cancer is BEING A
second is GETTING OLDER!
cent of the time there are no identifiable risk
a woman is diagnosed. You can reduce your risk for disease
and improve the quality of your life, but there are no
guarantees, or fool-proof formulas for preventing disease.
to take for
early detection of cancer.
thanks to Wendie Berg, MD, PhD, FACR, Breast Imaging
Consultant and Study Chair for the American
College of Radiology Imaging Network
(ACRIN) Protocol on Screening Breast
Ultrasound, for reviewing the material presented
for content and accuracy
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