3-D Mammograms screening

Traditional screening mammography is a lifesaving tool, which has helped to reduce breast cancer deaths in the United States by nearly 40% since 1990.1 The benefit would be even greater if more women chose to have screening mammograms.

In recent years, agencies that advise insurance companies, such as the U.S. Preventative Services Task Force, have tried to discourage younger women from undergoing routine screening and to recommend that older women undergo less frequent screening because of so-called “harms” of false-positives. False positives are abnormal findings on a mammogram that require further evaluation, most often non-invasive testing such as additional mammograms and possibly ultrasound. Fewer than 2% of women who have a mammogram will require a needle biopsy. Arguably, these “harms” pale in comparison to the consequences of missing an early breast cancer, which could mean that a woman has to undergo surgery, perhaps lose her breast, be infused with chemotherapy, and maybe even die prematurely.

 

3-D mammography

Newer screening technology called digital breast tomosynthesis (DBT), or 3-D mammography, is now available that both reduces false positives and improves early cancer detection. Ironically, there has been little support for mandated insurance coverage of this technology, which addresses the traditional shortcomings of conventional 2-D mammography.

Conventional screening mammography involves taking two images of each breast from different angles. In approximately the same time, DBT acquires images from multiple angles and produces approximately 55 images of each. Although a woman will barely notice the difference during her exam, DBT is a revolutionary technology that produces exquisitely detailed images of the breast. DBT allows us to peel back the breast tissue, layer by layer, to reveal small cancers hidden deep inside the breast. DBT also reduces the possible confusion caused by normal overlapping tissues, which can lead to false positives in conventional mammography.

The statistics from screening studies of DBT involving over half a million women indicate that it reduces false positive rates by approximately 15% to 37% and increases cancer detection by 10% to 35%.2-8 The cancers that are found by DBT are predominantly invasive cancers rather than “in situ” cancers or DCIS. Invasive cancers are the most important cancers to find because, if left untreated, they have the potential to shorten a patient’s life span.

DBT has demonstrated benefit for all women over the age of 40. For the approximately 40% of women with heterogeneously dense breasts, which is a particularly challenging population for conventional mammography, DBT has shown the potential to yield the greatest benefit.

 

Requests for DBT are being denied

The U.S. Food and Drug Administration has approved DBT, but it is not yet considered the standard of care for breast cancer screening. The California Chronic Care Coalition has asked the California Department of Managed Health Care (DMHC) to instruct health plans to classify DBT as an essential benefit. The California Radiological Society estimates the DMHC has received more than 4,000 Independent Medical Review (IMR) requests from patients whose health plans have denied covering 3-D mammograms, more than any other IMR in DMHC history. Ninety-four percent of IMRs filed result in the health plan reversing its decision and covering the screening service.

As patients become more aware of the benefits that DBT brings, they are asking for it. DBT costs $56 more than a traditional mammogram according to the Centers for Medicare and Medicaid Services. The cost to treat a Stage 4 breast cancer patient is nearly $224,000.

Physicians are adopting DBT nationwide as they replace older traditional 2-D units because it is clearly a superior technology. While conventional 2-D mammography continues to be the primary breast cancer screening method, experts predict that DBT will likely replace it within the next decade. DBT can identify a cancer up to 7 years before it will become large enough to identify during a self-exam. When found early, the 5-year survival rate for breast cancer is greater than 95%. Additionally, finding breast cancer early enables more women to select treatment options that allow them to keep their breasts.


References
  1. Howlader N, Noone AM, Krapcho M, Miller D, Bishop K, Altekruse SF, Kosary CL, Yu M, Ruhl J, Tatalovich Z, Mariotto A, Lewis DR, Chen HS, Feuer EJ, Cronin KA (eds). SEER Cancer Statistics Review, 1975-2013, National Cancer Institute. Bethesda, MD, http://seer.cancer.gov/csr/1975_2013/, based on November 2015 SEER data submission, posted to the SEER web site, April 2016.
  2. Skaane P, Bandos AI, Gullien R, et al. (2013) Comparison of digital mammography alone and digital mammography plus tomosynthesis in a population-based screening program. Radiology 267(1):47–56
  3. Ciatto S, Houssami N, Bernardi D, et al. (2013) Integration of 3D digital mammography with tomosynthesis for population breast- cancer screening (STORM): a prospective comparison study. Lancet Oncol 14(7):583–589
  4. Rose SL, Tidwell AL, Bujnoch LJ, et al. (2013) Implementation of breast tomosynthesis in a routine screening practice: an observational study. AJR Am J Roentgenol 200(6):1401–1408
  5. Friedewald SM, Rafferty EA, Rose SL, et al. (2014) Breast cancer screening using tomosynthesis in combination with digital mammography. JAMA 311(24):2499–2507
  6. McCarthy AM, Kontos D, Synnestvedt M. (2014) Screening outcomes following implementation of digital breast tomosynthesis in a general-population screening program. J Natl Cancer Inst 106(11):dju316
  7. Durand MA, Haas BM, Xiapan Y. (2014) Early clinical experience with digital breast tomosynthesis for screening mammography. Radiology 274:1313–1319
  8. Lourenco AP, Barry-Brooks M, Baird GL, Tuttle A, Mainiero MB. (2014) Changes in recall type and patient treatment following implementation of screening digital breast tomosynthesis. Radiology 274:1403–1417
  9. Haas BM, Kalr V, Geisel J, et al. (2013) Comparison of tomosynthesis plus digital mammography and digital mammography alone for breast cancer screening. Radiology 269(3):694–700
Kimberly Ray, MD
Kimberly Ray, MD, is an Associate Professor of Clinical Radiology and Associate Chief in the Breast Imaging section in the Department of Radiology and Biomedical Imaging at the University of California, San Francisco. Dr. Ray received her medical degree from the University of California, Irvine in 2001, and she completed a one-year internship from Loma Linda University Medical Center in California, in 2002. She finished a four-year Diagnostic Radiology residency from the University of California, Irvine in 2006, followed by a fellowship in Breast Imaging from UCSF in 2007.

2 COMMENTS

    • As an academic radiologist, I have no financial interests in any imaging equipment companies. There is in fact a large body of scientific evidence demonstrating that early detection with mammography decreases mortality from breast cancer. Randomized controlled trials, the gold standard for evaluating medical interventions, have shown a reduction in breast cancer deaths of 15-30% in women aged 40-74 years invited to screening mammography.(1) These trials necessarily underestimate the mortality benefit because not all women invited to participate actually complied with screening. Moreover, mammographic technique has significantly improved over the past few decades. Subsequent population based studies have shown a 40% reduction in breast cancer deaths for women 40 and older who participated in mammography screening programs. No doubt advances in breast cancer therapy have also contributed to reduction in breast cancer deaths. But therapy is more effective when cancer is found early, and less extensive surgery and fewer toxic systemic therapies are required for earlier stage disease.

      1. Smith R, Duffy S, Gabe R, Tabar L, Yen A, and Chen T. The randomized trials of breast cancer screening: what have we learned? Radiol Clin North Am 2004;42(5):793-806.

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