Gold standard in limbo as institute compares 2D, 3D mammography

KeepHealthCare.ORG – Gold standard in limbo as institute compares 2D, 3D mammography

Kimberly Durham, right, visiting Rocky Mountain National Park with her husband, Bob Stewart; daughter, Corri Stewart; and dog, Harpo, in September 2014. (Courtesy Photo)

In one day, Kimberly Durham became an outspoken booster of 3D mammography because conventional 2D mammography failed to detect multiple aggressive cancers in her left breast — even after magnetic resonance imaging confirmed it at the same appointment.

“That’s a problem, if you ask me, and I have insisted on 3D mammography ever since,” the 58-year-old Erie resident said. “… I was 50 at the time, and I wanted these years now when I have my grandchildren.”

But before 3D mammography gets gold standard of care status, the National Cancer Institute last fall launched the largest randomized clinical trial in decades to study the difference between conventional 2D mammography and 3D mammography.

Ultimately, NCI aims to study 165,000 healthy women — ages 45 to 74 — at about 100 mammography clinics nationwide and a few in Canada before publishing findings in 2025.

To detect breast cancer, traditional 2D mammography X-rays two sides of the breast. With 3D mammography, the scan uses those views along with X-rays shot from other angles to create a more detailed, computer-generated, 3D-like image.

About 30 percent of U.S. clinics offering mammography today already provide the 3D option, said Dr. Worta McCaskill-Stevens, director of NCI’s Community Oncology Research Program, which funded and launched this Tomosynthesis Mammographic Imaging Screening Trial.

“People think that new technology is the way to go,” she said of 3D mammography, which the Food and Drug Administration approved in 2011. “But in the world of medicine, we are trying to personalize treatment. We think of this trial as a way to personalize mammography in finding the cancers that are going to be life-threatening.”

‘Right sizing’ mammography

Because 3D mammography brings greater sensitivity to breast cancer screenings, some patients and clinics already consider it the gold standard for everyone, according to Dr. Etta Pisano, a radiologist at Beth Israel Deaconess Medical Center in Boston and the study chair of the ECOG-ACRIN Cancer Research Group that developed the trial with NCI.

“There are clinics where they don’t offer 2D mammography anymore for that reason. But that’s just marketing until we scientifically prove that 3D is a better tool than 2D at catching aggressive cancers that are the really bad actors,” she said.

“So, the sensitivity question is not the question we’re asking now,” Pisano continued. “There is always a trade-off. Anytime you have increased sensitivity, you usually have decreased specificity. What we’re looking to do now is learn enough to ‘right size’ mammography.”

To that end, she said that 3D mammography might not be a “one-size-fits-all” screening for breast cancer because it can increase false positives and unnecessary biopsies of suspicious cells. Because it is frequently performed along with 2D mammography, it also increases radiation exposure, though radiation related to either exam is comparatively small and within national guidelines for screening mammography.

“We don’t know if 3D is better at finding the fastest growing cancers — the ones where early diagnosis makes a big difference in their chance for cure, or whether it is mainly finding the slower growing tumors,” Pisano added.

The study also aims to sift out what kind of woman benefits most from this type of screening — possibly someone such as Durham, the Erie breast cancer survivor with dense breast tissue.

The dense breast tissue factor

About half of women have what doctors consider dense breasts, and dense breast tissue challenges 2D mammography most, Pisano said.

It can only capture a flat, two-dimensional image akin to the moon’s flat appearance in the sky, as opposed to a 3D mammography view with much more depth to see better around all the fibrous artifacts that can hide aggressive cancers that begin as tiny tumors.

To raise awareness around this risk factor, Dr. Taj Kattapuram — a Centura Health radiologist at Avista Adventist Hospital in Louisville and the Colorado Radiological Society’s legislative chair — lobbied for a bill that became law last October.

It requires radiologists to notify women of their breast density level along with their mammogram results.

Durham knows dense breast tissue is a factor that already puts her at a slightly greater risk of developing breast cancer and at greater risk of unclear traditional 2D mammography screenings.

“So, I am obsessed, absolutely, with getting 3D mammograms,” she said. “When we moved to Colorado in 2014 from the East Coast, I had to go all the way to Aurora to find the pink bus that I knew had it,” she said.

Many local clinics and hospitals offering mammography services since have invested in the 3D technology.

The Women’s Imaging Center at Longmont United Hospital — an American College of Radiology Breast Center of Excellence for 10 consecutive years — began offering 3D mammography in 2014, Director Dr. Horacio Gutierrez said.

“While women with dense breasts and high-risk women may benefit more from 3D mammography, we recommend 3D annual screening mammography to all women beginning at age 40,” he said. “We believe that 3D mammography is the new standard of care.”

Boulder Community Health’s Foothills Hospital in Boulder — also designated as an American College of Radiology Breast Center of Excellence — invested in 3D mammography in 2015 and again in 2017 with plans to add more units, BCH spokesman, Richard Sheehan, said.

Other clinics and hospitals countywide — such as SCL Health’s Good Samaritan Medical Center in Lafayette and Centura Health’s Avista Adventist Hospital in Louisville — also offer 3D mammography.

UCHealth’s Longmont Clinic, meanwhile, uses 2D mammography only, spokeswoman Kelly Tracer said.

“We are planning to upgrade the system so we can offer our Longmont-area patients three-dimensional mammography,” she said. “Unfortunately, due to the heavy load this type of equipment demands of a facility’s infrastructure, we have run into technological hurdles that have caused delays.”

She added that the University of Colorado School of Medicine and UCHealth have been approved to participate in the clinical trial underway now to compare both types of mammography.

The trial has opened enrollment at three Colorado clinics thus far: The Women’s Imaging Center in Denver; Radiology Imaging Associates in Englewood; and the Penrose-St. Francis Healthcare in Colorado Springs.

3D discussion broadening insurance coverage and health literacy

Thought the trial will continue enrolling clinics for another 15 months and won’t publish final results for seven years, some states already have moved to mandate full coverage for 3D mammography.

The Affordable Care Act covers all 2D mammography breast cancer screenings. Medicare announced full coverage of 3D mammography about five years later in 2015. Last summer, Anthem Blue Cross Blue Shield followed suit.

But the Colorado Department of Public Health and Environment, which targets low-income women with health navigators to promote health literacy and self-advocacy around breast cancer screening, is in a wait-and-see mode, spokesman Dave Brendsel said.

“CDPHE has identified some early indication of positive outcomes from use of 3D mammography, but we believe there is not yet definitive evidence to promote its use with our clients,” he said.

Consequently, the department offers no printed or online materials dedicated specifically to the risks and benefits associated with both 2D and 3D mammography.

Breast cancer survivor Durham knows the jury is out.

“And I know this,” she said between trips out of state to visit her kids and grandkids, “I got treated at Stage 1, when I had a 90 percent chance of recovering, instead of getting treated a year later, when that chance of recovery could have dropped to 20 percent.”

Pam Mellskog can be reached at [email protected] or at 303-746-0942.


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