Breast cancer is second to lung cancer as the leading cause of death among women in the
United States. Over 40,000 women were estimated to die of breast cancer in 2016. Early
detection is key to improved survival, and overall prognosis is directly linked to the
stage of disease at the time of diagnosis. The 5-year relative survival rate has
increased since the mid 1970's, in part owing to improvements in early breast cancer
detection with screening mammography. Screening with mammography is associated with a
16-40% relative reduction in breast cancer mortality among women aged 40-74 years old,
and mammography is the most cost-effective method of breast cancer screening. However,
cancers can be missed at mammography, particularly in women with dense breasts. Screening
with mammography alone may be insufficient in the screening of women who are at high risk
of breast cancer. The need for more effective screening strategies to supplement
mammography in these groups of women has led to the use of dynamic contrast-enhanced
(DCE) breast MRI. Of the available modalities for evaluation of the breast, MRI has been
found to have the highest sensitivity for the detection of breast cancer, irrespective of
breast density.
On the basis of evidence from nonrandomized trials and observational studies, breast MRI
is indicated as a supplement to mammography for patients at high risk with greater than
20% relative lifetime risk. This cohort of women includes those with: a known BRCA1 or
BRCA2 genetic mutation, an approximately 20-25% or greater lifetime risk of breast cancer
according to risk assessment tools, a strong family history of beast or ovarian cancer, a
history of being treated for Hodgkin's disease and certain genetic syndromes (i.e.
Li-Fraumeni syndrome, Cowden syndrome or Bannayan-Riley-Ruvalcaba syndrome). However, for
women at intermediate risk, including those with dense breast tissue, screening MRI in
the United States is not cost-effective. The cost-effectiveness of screening breast MRI
depends on estimated breast cancer incidence and examination cost. The rationale for
limiting supplemental screening breast MRI to those at greatest risk is in part due to
its high cost.
Investigators have looked at ways of reducing the cost of breast MRI to improve access to
it as a supplement screening method for women who are not necessarily in the highest risk
group. One way to achieve the efficiency and rapid throughput found with screening
mammography is to shorten screening breast MRI protocols, decrease image acquisition
time, and shorten image interpretation time. Study results have suggested that shorter
protocols and shorter acquisition times can be achieved with maintenance of diagnostic
accuracy comparable to that obtained with conventional MRI protocols. Use of these
abbreviated MRI protocols could result in lower cost and faster throughput, increasing
availability and providing women with dense breasts or at intermediate risk (lifetime
risk, 15-20%) greater access to breast MRI.
