Miglioretti awarded $7.5 million to evaluate supplemental breast imaging

In In The News by Barbara Jacoby

Diana Miglioretti, UC Davis dean’s professor of biostatistics and an internationally recognized breast cancer screening expert, has received $7.5 million to determine the effectiveness of two supplemental breast screening and diagnostic workup strategies — digital breast tomosynthesis (3D mammography) and magnetic resonance imaging (MRI) — used with mammography for cancer detection. Miglioretti’s team also will work to determine whether effectiveness of the screening strategies depends on a woman’s breast density.

The award was one of four announced May 23 by the Patient-Centered Outcomes Research Institute (PCORI) Board of Governors that will examine various care options for treatment of a range of conditions and problems that impose high burdens on patients, caregivers and the health care system.

Miglioretti and her colleagues will use data from the Breast Cancer Surveillance Consortium (BCSC), the nation’s largest collection of information on breast imaging. The BCSC consists of six breast imaging registries across the U.S., including the Group Health Research Institute in Seattle, Wash., where Miglioretti is a senior investigator and leads the BCSC’s Statistical Coordinating Center.

Understanding the role of supplemental screening is extremely important because its use is growing rapidly, Miglioretti said, but too little evidence exists to prove it’s effective. Tomosynthesis, also known as 3D mammography, is of particular concern because about half of mammography centers now offer the technology, and many radiologists in the U.S. are using it to screen all women, with little understanding of which women may benefit or potentially be harmed. The technology is added to an existing mammography machine and turned on during a screening for the added 3D imaging.

“3D mammography holds great promise of improving breast cancer detection and decreasing the rate of false alarms,” said Miglioretti. “But some women may not benefit from tomosynthesis, and some may even experience more harms and unnecessary costs.”

Miglioretti noted that tomosynthesis costs about $50 extra per screening, which may not be covered by health insurance.

“We want to know whether performing the test adds clinical value, in particular in women with dense breasts,” she said.

Complicating the breast screening landscape is that more than half of states now have breast density laws that require notification of women if they have dense breasts. These laws aim to inform women of the increased risk of breast cancer and the fact that mammography is not as effective at finding cancers in women with dense breasts. An estimated two-thirds of pre-menopausal women and one-quarter of post-menopausal women have dense breasts, and many are now getting some kind of supplemental imaging beyond digital mammography.

“These laws require informing women if they have dense breasts on a mammogram, and yet we don’t know what to do differently for these women,” she said. “Mammography is still our best tool for detecting breast cancer in women with dense breasts. We want to see if adding tomosynthesis or MRI might improve cancer detection in these women.”

In addition to an examination of supplemental breast imaging for screening, Miglioretti and colleagues will study whether using breast MRI prior to surgery enhances surgical planning in women with a newly diagnosed breast cancer, particularly for women with dense breasts, and if it ultimately reduces the rate of breast cancer recurrence.

“This is another important area where there is insufficient evidence,” said Miglioretti. “Does pre-operative MRI find additional cancers that are life threatening? MRI is more sensitive than mammography, but it also leads to more false alarms and more biopsies.”

Collaborators on the PCORI award include co-principal investigators Karla Kerlikoskowske at UC San Francisco and Tracy Onega and Anna Tosteson at Dartmouth College.

The PCORI award is one of many that Miglioretti has received to use BCSC data for analysis of breast screening strategies to better inform clinical practice and help women make the best screening decisions. Her study, published in the Journal of American Medical Association Oncology in 2015, concluded that a screening mammogram once every two years is safe for postmenopausal women at average risk of breast cancer. The work helped inform the American Cancer Society’s revised mammography guidelines. Miglioretti and colleagues also developed the BCSC risk calculator (https://tools.bcsc-scc.org/BC5yearRisk/) being used to identify women with dense breasts at high risk of missed cancers.

Miglioretti, a professor in the UC Davis Department of Public Health Sciences, is also a scientific member of the UC Davis Comprehensive Cancer Center.

The PCORI board approved the breast screening research award pending completion of a business and programmatic review by PCORI staff and issuance of a formal award contract. PCORI is an independent, nonprofit organization authorized by Congress in 2010 to fund research that will provide patients, their caregivers, and clinicians with the evidence-based information needed to make better informed health care decisions.

The BCSC registries and registry leads participating in this study include  Carolina Mammography Registry in North Carolina, led by Louise Henderson; New Hampshire Mammography Network, led by Tracy Onega; San Francisco Mammography Registry in the San Francisco Bay Area, led by Karla Kerlikowske; Vermont Breast Cancer Surveillance System, led by Brian Sprague; Group Health Registry within Group Health Cooperative in Washington state, led by Diana Buist and Metro Chicago Breast Cancer Registry, within Advocate Health Care in metropolitan Chicago, led by Garth Rauscher. For more information about the Breast Cancer Surveillance Consortium, visit http://breastscreening.cancer.gov.