Women at high risk (greater than 20% lifetime risk) should get an MRI

Women at high risk (greater than 20% lifetime risk) should get an MRI and a
mammogram every year. Women at moderately increased risk (15% to 20%
lifetime risk) should talk with their doctors about the benefits and limitations of
adding MRI screening to their yearly mammogram. Yearly MRI screening is not
recommended for women whose lifetime risk of breast cancer is less than 15%.
Women at high risk include those who:

· Have a known BRCA1 or BRCA2 gene mutation
· Have a first-degree relative (parent, brother, sister, or child) with a BRCA1 or BRCA2
gene mutation, but have not had genetic testing themselves
· Have a lifetime risk of breast cancer of 20% to 25% or greater, according to risk
assessment tools that are based mainly on family history (such as the Claus model -
see below)
· Had radiation therapy to the chest when they were between the ages of 10 and 30
years
· Have Li-Fraumeni syndrome, Cowden syndrome, or Bannayan-Riley-Ruvalcaba
syndrome, or have first-degree relatives with one of these syndromes
Women at moderately increased risk include those who:
· Have a lifetime risk of breast cancer of 15% to 20%, according to risk assessment
tools that are based mainly on family history (see below)
· Have a personal history of breast cancer, ductal carcinoma in situ (DCIS), lobular
carcinoma in situ (LCIS), atypical ductal hyperplasia (ADH), or atypical lobular
hyperplasia (ALH)
· Have extremely dense breasts or unevenly dense breasts when viewed by
mammograms
If MRI is used, it should be in addition to, not instead of, a screening mammogram. This
is because while an MRI is a more sensitive test (it's more likely to detect cancer than a
mammogram), it may still miss some cancers that a mammogram would detect.
For most women at high risk, screening with MRI and mammograms should begin at age
30 years and continue for as long as a woman is in good health. But because the evidence
is limited about the best age at which to start screening, this decision should be based on

shared decision making between patients and their health care providers, taking into
account personal circumstances and preferences.
Several risk assessment tools, with names like the Gail model, the Claus model, and the
Tyrer-Cuzick model, are available to help health professionals estimate a woman's breast
cancer risk. These tools give approximate, rather than precise, estimates of breast cancer
risk based on different combinations of risk factors and different data sets.
As a result, they may give different risk estimates for the same woman. For example, the
Gail model bases its risk estimates on certain personal risk factors, like current age, age at
menarche (first menstrual period) and history of prior breast biopsies, along with any
history of breast cancer in first-degree relatives.
The Claus model estimates risk based on family history of breast cancer in both first and
second-degree relatives. These 2 models could easily give different estimates using the
same data. Results from any of the risk assessment tools should be discussed by a woman
and her doctor when being used to decide whether to start MRI screening.
It is recommended that women who get screening MRI do so at a facility that can do an
MRI-guided breast biopsy at the same time if needed. Otherwise, the woman will have to
have a second MRI exam at another facility at the time of biopsy.
There is no evidence right now that MRI is an effective screening tool for women at
average risk. MRI is more sensitive than mammograms, but it also has a higher falsepositive
rate (it is more likely to find something that turns out not to be cancer). This
would lead to unneeded biopsies and other tests in many of these women, which can lead
to a lot of worry and anxiety.
The American Cancer Society believes the use of mammograms, MRI (in women at high
risk), clinical breast exams, and finding and reporting breast changes early, according to
the recommendations outlined above, offers women the best chance to reduce their risk of
dying from breast cancer. This combined approach is clearly better than any one exam or
test alone.
Without question, a breast physical exam without a mammogram would miss the
opportunity to detect many breast cancers that are too small for a woman or her doctor to
feel but can be seen on mammograms. Although mammograms are a sensitive screening
method, a small percentage of breast cancers do not show up on mammograms but can be
felt by a woman or her doctors. For women at high risk of breast cancer, like those with
BRCA gene mutations or a strong family history, both MRI and mammogram exams of
the breast are recommended.