Oct. 28, 2014
Tomosynthesis Improves Cancer Detection in Women with Dense Breast Tissue
New Study Shows Cost-Effectiveness for Combining Digital Mammography and Tomosynthesis
when Screening Women with Dense Breasts
SEATTLE – As of October 2014, 19 states have enacted laws requiring women to be directly
informed if they have dense breasts and would benefit from supplemental screening. However,
the recommended type of supplemental screening for women with dense breasts remains unclear.
With 15 additional states considering similar laws and federal legislation introduced, physician
scientists at the University of Washington and Seattle Cancer Care Alliance (SCCA) investigated
the potential impact of supplemental screening for women with dense breast tissue. The study’s
findings are published this month online in the journal Radiology.
The study found that adding tomosynthesis (3D mammography) to routine biennial digital
mammography screening among U.S. women with dense breasts could improve health outcomes
at a reasonable cost relative to digital mammography screening alone. This is the first
comparative effectiveness study performed at the national level using an established model, and
it could influence future screening recommendations for women with dense breast tissue who
comprise nearly half of all women in the United States.
“We felt that this analysis would help inform timely policy and practice decisions given both
increased attention to screening for women with dense breasts and rapid adoption of
tomosynthesis in routine practice,” said Christoph I. Lee, M.D., M.S.H.S., lead author of the
study, assistant professor in the Department of Radiology and Health Services at the University
of Washington and staff radiologist at SCCA. “While screening ultrasound is currently being
touted as the additional test of choice for women with dense breasts, it requires significant
increases in manpower and leads to a larger number of false positives. Digital breast
tomosynthesis, in contrast to ultrasound, offers operational and ease-of-use advantages since it is
an integrated part of newer-generation mammography units.”
Mammography remains the only screening test proven to decrease mortality from breast cancer.
However, mammography is less accurate in women with dense breasts for whom cancers may be
masked by overlapping breast tissue. Moreover, dense breasts compared to average-density
breasts are associated with a moderate increased relative risk for developing breast cancer
independent of the masking effect. Given that nearly half of the U.S. screening population has
dense breasts, an increasingly large number of women may be encouraged to consider
supplemental screening beyond conventional mammography.
According to Constance Lehman, M.D., Ph.D., chief of breast imaging at the University of
Washington, and director of imaging at Seattle Cancer Care Alliance, “Prior research has
reported improved diagnostic accuracy with tomosynthesis, with both fewer false positives and
higher cancer detection rates. However, until this study, we had little understanding of the
impact of that improved performance on patient outcomes and costs.”
For this study, researchers used a breast cancer simulation model previously used to guide the
U.S. Preventive Services Task Force recommendations for breast cancer screening. The team
estimated the comparative clinical effectiveness and cost effectiveness of biennial screening with
both digital mammography and tomosynthesis versus digital mammography alone among U.S.
women ages 50 to 74 years with dense breasts, using data and metrics from the National Cancer
Institute’s Breast Cancer Surveillance Consortium, Medicare reimbursement rates, and medical
literature. They found that one breast cancer death would be prevented and 810 false-positive
exams avoided per 2,000 women screened over 12 rounds of screening, and that the incremental
cost per quality-adjusted life year (QALY) gained by adding tomosynthesis to digital
mammography screening was $53,893, well below the established threshold for cost
effectiveness ($100,000 per QALY gained).
“The population outcomes we report show the promise of tomosynthesis, but it is critical to
emphasize the need for primary data on tomosynthesis performance in U.S. community settings,”
said Anna Tosteson, Sc.D., a co-author and James J. Carroll Professor at the Geisel School of
Medicine at Dartmouth. “As such evidence becomes available, population modeling will be
needed to elucidate the most clinically effective and efficient approaches to screening women
with mammographically dense breast tissue.”
The study team currently uses effectiveness data from European trials to estimate the effects of
adding tomosynthesis among the U.S. population. “While this modeling study suggests that there
is a high likelihood that breast tomosynthesis will be cost-effective in the U.S., further primary
data from ongoing and planned studies will be very important to reduce uncertainty regarding the
model estimates, ” said Scott Ramsey, M.D., Ph.D., another study co-author and co-director of
the Hutchinson Institute for Cancer Outcomes Research.
“Overall, this study provides women, physicians, payers and policymakers in the U.S. with much
needed information regarding the balance between potential benefits and harms of combined
mammography and tomosynthesis screening for women with dense breast tissue,” Dr. Lee said.
Drs. Lee, Lehman, and Ramsey are researchers in the Hutchinson Institute for Cancer Outcomes
Research (HICOR) at Fred Hutch in Seattle. The study was supported in part by the National
Cancer Institute (NCI) and in part by a Radiology Research Academic Fellowship, co-sponsored
by GE Healthcare (Waukesha, Wisconsin) and the Association of University Radiologists. The
sponsors had no role in the study concept, study design, data analysis, interpretation, or reporting
of the results. The authors had full control of the data and information submitted for publication.
For more information on research happening at SCCA and Fred Hutch for women with dense
breasts, please visit http://www.seattlecca.org/clinical-trials/breastcancer-NCT02042456.cfm.
Editor’s note: Please contact Linda Brooks, Senior Manager Media Relations of the
Radiological Society of North America, at lbrooks@rsna.org to obtain an embargoed copy of the
paper “Comparative Effectiveness of Combined Digital Mammography and Tomosynthesis.”
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“Comparative Effectiveness of Combined Digital Mammography and Tomosynthesis Screening
for Women with Dense Breasts.” Collaborating with Dr. Lee were Mucahit Cevik, M.S.,
Oguzhan Alagoz, Ph.D., Brian L. Sprague, Ph.D., Anna N.A. Tosteson, Sc.D., Diana L.
Miglioretti, Ph.D., Karla Kerlikowske, M.D., Natasha K. Stout, Ph.D., Jeffrey G. Jarvik, M.D.,
M.P.H., Scott D. Ramsey, M.D., Ph.D., and Constance D. Lehman, MD, Ph.D.
About Seattle Cancer Care Alliance
Seattle Cancer Care Alliance is a cancer treatment center that unites doctors from Fred
Hutch, UW Medicine and Seattle Children’s. Our goal, every day, is to turn cancer patients
into cancer survivors. Our purpose is to lead the world in the prevention and treatment of
cancer. SCCA has five clinical care sites: an outpatient clinic on the Fred Hutch campus, a
pediatric inpatient unit at Seattle Children’s, an adult inpatient unit at UW Medical Center, a
medical oncology clinic at EvergreenHealth, and medical and radiation oncology clinics at
UW Medicine / Northwest Hospital & Medical Center. Additionally, proton therapy services
are provided at SCCA Proton Therapy, A Procure Center. For more information about
SCCA, visit www.seattlecca.org.
Media Contact:
Stephany Rochon
Nyhus Communications for Seattle Cancer Care Alliance
206.323.3733
SCCA@Nyhus.com