2013 – As concerns over the efficacy of screening patients with dense
breast mounts, California-based breast imagers and breast cancer risk
specialists launch a website to help navigate the new challenges posed by
breast density notification laws, according to a recent study.
While mammography remains the gold standard for breast screening,
mammograms miss about 20% of breast cancers present at screening.
The main cause of these false-negative results is high breast density, which is
usually collectively referred to as fibroglandular tissue. A phenomenon known
as masking, in which the surrounding dense breast tissue obscures a cancer, may
occur during mammography.
In response, several states have adopted laws requiring patient and
referring physician notification when the interpreting radiologist determines
that the pattern of fibroglandular tissue on a patient’s mammogram is
In California, mandatory reporting requirements took effect on April 1,
2013. The law requires that patients with dense breast tissue on screening
mammography receive notification in writing, with advice on discussing their
screening options with their primary physician.
“The legislation was prompted by breast cancer advocacy groups
motivated to educate women regarding the limitations of mammography,” said Jafi
A. Lipson, M.D., assistant professor of radiology at Stanford University School
of Medicine in Stanford, Calif.
This legislation could have significant impact on patient care as
approximately 50% of women undergoing screening mammography classified as
having either “heterogeneously dense” or “extremely dense” breasts.
As more states implement the law, the mandate is gaining momentum on
the national stage. On January 18, 2011, federal legislation for dense breast
notification was introduced in Congress, but it has yet to be enacted. Also, the
U.S. Food and Drug Administration (FDA) is considering adding a breast density
reporting amendment to the MQSA. This means that women would receive
standardized nationwide notification about their breast tissue density after
their mammograms. The FDA said it would consider the proposed rule in December
For California alone, this could mean 2 million notification letters a
year, and a significant increase in supplementary screening with MRI and
ultrasound, according to the study.
The broad classification of breast density under California law does
not take into account the varying risk levels among patients with different
breast densities. When risk is expressed relative to average breast density,
the risk for the 40% of women with heterogeneously dense breasts is about 1.2
times greater than average and the risk for the 10% of women with extremely
dense breasts is about 2.1 times greater than average. Therefore, breast
density is a risk factor, but not a strong one.
“While additional screening for women with extremely dense
breasts could prove beneficial, supplemental screening of the approximately 40%
of California women with heterogeneously dense breasts would result in very
substantial additional cost to the healthcare system,” Dr. Lipson said. “There
also is concern that the increased use of supplementary screening will
ultimately expose some patients to more harm, in the form of false-positive
results, than good.”
address these challenges, Dr. Lipson and colleagues in the California Breast
Density Information Group (CBDIG) created an online document to answer
frequently asked questions about the efficacy, benefits and harms of
supplementary screening tests.
“Increased patient awareness may be considered a benefit, although
there are also potential harms of notification, including awareness without a
clear path forward for women and care providers, increased unsubstantiated
anxiety, potential for misunderstanding or overestimation of density-associated
risk and increased propensity to over-screen,” Dr. Lipson said.
recommends an individualized risk-based approach for guiding the
decision-making process. Women with a high risk of breast cancer, such as those
with the BRCA genetic mutation, are more likely to benefit from additional
screening with MRI or ultrasound, or with tomosynthesis—a promising supplementary
screening technology. For women with intermediate risk, the decision to have a
screening MRI should be made on a case-by-case basis using a shared
of additional screening are diminished in women who are not high risk, while
the potential harms remain the same.
“Studies show a small number of added cancers are found with
supplementary screening breast ultrasound,” Dr. Lipson said. “However, this is
at the price of a large number of benign breast biopsies.”
researchers suggested that women who request supplementary breast screening may
be rapidly triaged for assessment based on their individual risk factors.
legislature did not mandate insurance coverage for any supplementary breast
cancer screening tests, and there are no insurance billing codes for screening
breast ultrasound or tomosynthesis. Only one state, Connecticut, has a
notification law and an insurance mandate, so many women who desire certain
types of supplementary screening may be asked to pay out of pocket.
www.rsna.org and www.appliedradiology.com
Lipson JA, Price ER, Hargreaves J, et al. The California Breast Density
Information Group: A collaborative response to the issues of breast density, breast
cancer risk, and breast density notification legislation. Radiology. 2013;10.1148/radiol.13131217.