Recently, the Governor of Michigan signed into law a requirement that radiologists inform women if their mammogram reveals dense breasts. The law will take effect on June 1, 2015. With this act, Michigan became the 21st state to enact legislation on mandatory reporting of breast density found in breast cancer screening.

The surprisingly controversial law, having to do with a woman’s right to know if her mammogram result is unclear, may go national: Last July, Senators Dianne Feinstein (D-Calif.) and Kelly Ayotte (R-N.H.) introduced the Breast Density and Mammography Reporting Act. Similar legislation repeatedly has been put before Congress by Rep. Rosa DeLauro (D-CT) and co-sponsors.

Meanwhile the FDA may update its Mammography Quality Standard Act (MQSA) program to require reporting of breast density to women. So this is a big deal.

Elaine Schattner

Breast density is said to limit as many of half of screening mammograms. Although the widespreadness of dense breasts is a contestable point, as things stand millions of women are likely to receive notices about having the condition this year, in 2015. The question then is what should they do with this information, if anything?

Dense breasts are loaded with fibrous and glandular (“fibroglandular”) tissue. This benign condition is most common in premenopausal women but does occur in some women who are older. When radiologists review breast images, they may score the density from 1 to 4 (lowest to highest) or a – d, based on the American College of Radiology (ACR) BI-RADS scale.

A problem in screening women with dense breasts for cancer is that fibrous and glandular tissue are (literally) dense, rendering cloudy-white, blobby images in mammograms. Normal fat, by contrast, tends to appear dark gray or black in the images. The benign fibroglandular material tends to mask cancer, so a radiologist is less likely to see it. According to the NCI, breast density is the main cause of false negatives (when screening fails to detect cancer that is present) in mammography.

The issue reporting laws might address is two-fold. First – that women with dense breasts should be informed that their mammograms are cloudy and hard to read; they should understand that a negative study, one which fails to detect cancer, doesn’t mean they’re cancer-free. Second – that upon knowing they have dense breasts, women might choose additional screening such as by breast ultrasound, MRI, or a newer method.

As articulated by Nancy M. Cappello, Ph.D., who founded the non-profit organization AreYouDense, women have every right to know if they have dense breasts and if they’re at increased risk for a hidden tumor. She called the false reassurance of a negative mammogram a Happygram – referring to when a woman with dense breasts is told her screening mammogram is normal or doesn’t show breast cancer, but in fact the test is uninterpretable.

Cappello’s advocacy stems from personal experience. As detailed in the American Journal of Roentgenology (AJR), she received a diagnosis of Stage IIIC breast cancer involving 13 lymph nodes in her armpit. Her tumor was found by clinical examination weeks after a reportedly normal mammogram. Because she’d gone for regular screening, Cappello was surprised that doctors didn’t detect the malignancy at an earlier stage, when less treatment would have been needed and the prognosis would have been better. It was only after her diagnosis that Cappello learned she had extremely dense breast tissue. As reported, her physician and radiologist knew of the breast density but did not share this information with her, the patient.

Cappello lobbies hard for breast density reporting laws. “Women have the right to know about this issue,” she said by phone. “This work never ceases to amaze me. We encounter opposition from women, from radiologists, from obstetricians and gynecologists and from physicians’ trade groups.”

The situation is changing, Cappello notes. In Tennessee and Arizona, the legislation was initiated by physicians.

Not all doctors are pleased about the reporting mandates. Nor do all agree it’s advisable.

An editorial in the latest AJR by Dr. Marcia C. Javitt, a radiologist on faculty of the Uniformed Services University of the Health Sciences, cautions that breast density measurement is unreliable, subjective and inconsistent. About 50 percent of mammograms are limited by breast tissue, she writes. “If all of these women opt for adjunct screening procedures, a staggeringly high number of alternative screening studies in the United States could overwhelm the available resources.”
Dr. Etta Pisano is a breast imaging specialist and professor of radiology at the Medical University of South Carolina. “The first and most overwhelming reason why many radiologists oppose the legislation is because they think doctors should have a private relationship with their patients. The government is stepping where it doesn’t belong,” she said in a phone interview.

Apart from a “philosophical disagreement” about the government’s role in health care, there’s little data to support the benefit of mandatory breast density reporting, Pisano emphasized. “All it does is frighten patients without offering them a solution,” she said.
“There is no evidence to support additional imaging after mammography, either by sonogram or MRI among women with average risk for developing breast cancer,” she said. “So it’s not clear how finding out they have dense breasts would lead to better outcomes.”

“Ultrasound is a very operator-dependent technology,” Pisano considered. “If you’re going to apply screening across a population, you need to show it works across the population and not just in selected practices,” she said.

Not all insurance covers ultrasound, Pisano added. “The rate of false positives is high, which adds to the cost,” she said. “In my opinion, MRIs may be better than ultrasound at picking up small tumors when the mammogram is unclear, in women with increased risk,” she said. “But those are more expensive.”

“It doesn’t matter if your breasts are dense or not,” Pisano concluded. “Women should be vigilant.”

There does seem to be a consensus among radiologists that ultrasound aids breast cancer detection in women with dense breasts. A current review details a 2002 study involving over 11,000 women. In that analysis, sonograms proved a powerful addition to mammography in screening. Among women with dense breasts at average risk for breast cancer, combining mammograms with sonograms raised detection of invasive tumors by 42 percent, and led to detection of smaller cancers.

What’s appealing to many women about ultrasound is that it doesn’t involve radiation. Also, it’s relatively inexpensive – costing a few hundred dollars in most facilities. The problem is that ultrasound delivers a high number of false positives – abnormalities noted and warranting biopsy, that turn out to be benign. Many radiologists bemoan ultrasounds because they’re labor-intensive. For this reason, some companies like GE and SonoCiné are working to automate the ultrasound process and developing computer-assisted diagnostic tools.

Some radiologists favor breast MRIs, which are expensive and also have a high false positive rate. Others are investigating newer imaging technologies, such as molecular breast imaging (MBI). These screening tools, however, are expensive and comparatively untested.

As considered in the February AJR, the state laws vary. So far they all require that women with dense breasts be informed directly by radiologists – and not just their doctors – that the mammogram is limited by this condition. Some states require a statement about the linkage of dense breasts to increased cancer risk, although that association is controversial. Some states require that the letter mention the possible need for additional testing.

But only five states with reporting laws have provisions for insurance coverage of additional tests. This is a legitimate concern, acknowledged by pretty much everyone involved. The lack of insurance for follow-up ultrasound or MRI can leave women with dense breasts worried and unable to pursue the next step, should they choose further evaluation. This lack of insurance coverage may lead to economic disparity in mammography follow-up and, potentially, in early diagnosis of breast cancer.

What’s clear is that many women with dense breasts and cloudy mammograms won’t be sure what to do. Their doctors may not be sure what’s best and may disagree; many gynecologists and primary care physicians will toe the line that further screening isn’t worth it.

As of this time, the radiology community appears torn. Meanwhile, breast cancer remains the most common malignant cause of death in U.S. women under the age of 60 years.