Are 3-D mammograms really better? US puts scans to the test

December 7, 2017 by Lauran Neergaard
Are 3-D mammograms really better? US puts scans to the test
In this Nov. 21, 2017 photo provided by the Montefiore Health System, Dr. Tova Koenigsberg at The Montefiore Einstein Center for Cancer Care in New York shows an example of a traditional mammogram scan. U.S. health officials are beginning a huge study to compare traditional mammograms with 3-D versions, to see if the newer choice might really improve screening for breast cancer. (Montefiore Health System via AP)

A better mammogram? Increasingly women are asked if they want a 3-D mammogram instead of the regular X-ray—and now U.S. health officials are starting a huge study to tell if the newer, sometimes pricier choice really improves screening for breast cancer.

It's the latest dilemma in a field that already vexes women with conflicting guidelines on when to get checked: Starting at age 40, 45 or 50? Annually or every other year?

The issue: Mammograms can save lives if they catch aggressive breast cancers early. But they also can harm through frequent false alarms and by spotting tumors that grow so slowly they never would have posed a threat—overdiagnosis that means some women undergo unneeded treatment.

That trade-off is a key question as doctors begin recruiting 165,000 women nationally to compare potentially more beneficial 3-D mammograms—known scientifically as "tomosynthesis"—with standard two-dimensional digital mammography.

The 3-D mammograms have been marketed as being able to find more cancers.

"But the idea isn't so much finding more cancers as finding the cancers that are going to be life-threatening," said Dr. Worta McCaskill-Stevens of the National Cancer Institute, which is funding the new research to tell whether the 3-D scans truly pinpoint the tumors that matter most.

It's one of the largest randomized trials of mammography in decades, and scientists designed the research to do more than answer that key 3-D question. They hope the findings also, eventually, will help clear some of the confusion surrounding best screening practices.

"The most important thing about this study is that it's moving us to individualized screening as opposed to what we have now, which is one-size-fits-all screening," predicted study chair Dr. Etta Pisano, a radiologist at Boston's Beth Israel Deaconess Medical Center.

"We are going to have a much better understanding of how to screen women so that we do the least amount of harm."

WHO NEEDS A MAMMOGRAM?

That depends on whom you ask. Guidelines vary for women at average risk of breast cancer. (Those at increased risk, because of family history or genetics, already get different advice.)

The American College of Radiology recommends annual mammograms starting at age 40.

The American Cancer Society urges annual checks starting at 45 and switching to every other year at 55, though it says women 40 to 44 still can opt for a mammogram.

And the U.S. Preventive Services Task Force, a government advisory group, recommends starting at age 50, with mammograms every other year. It, too, says 40-somethings can choose earlier screening.

WHAT ABOUT 3-D MAMMOGRAMS?

Standard mammograms take X-rays from two sides of the breast. With tomosynthesis, additional X-rays are taken at different angles—not truly three-dimensional but a computer compiles them into a 3-D-like image. First approved by the Food and Drug Administration in 2011, they're not yet the standard of care in part because of questions that the new study aims to answer.

Some studies have found tomosynthesis detects more cancer with fewer false alarms; they're often advertised as particularly useful for younger women's dense breasts.

HOW TO DECIDE?

Understand that mammograms come with pros and cons, and weigh them, said Dr. Otis Brawley, the American Cancer Society's chief medical officer.

Breast cancer is far less common at age 40 than at age 50 and beyond. After menopause, tumors tend to grow more slowly and women's breast tissue becomes less dense and easier for mammograms to provide a clearer image.

Consider: For every 1,000 women screened every other year until their 70s, starting at 40 instead of 50 would prevent one additional death—but create 576 more false alarms and 58 extra unneeded biopsies, the task force estimated. Also, two extra women would be treated for tumors that never would have become life-threatening—that overdiagnosis problem.

As for what type to choose, some insurers, including Medicare, cover the 3-D version, and a small number of states mandate coverage. Other insurers may require women to pay $50 to $100 more out of pocket. Whoever ultimately pays, extra time to analyze the scans adds to the cost.

THE NEW STUDY

About 100 mammography clinics across the U.S., and a few in Canada, will enroll healthy women ages 45 to 74 who already are planning to get a routine mammogram. They'll be randomly assigned to get either the regular or 3-D version for five years. Most will be screened annually but post-menopausal women who don't have certain cancer risk factors will be screened every other year.

Researchers will track every woman's results including samples from biopsies plus genetic and other tests, as well as how any cancer patients fare. The giant database hopefully will help them tease out more information about which women benefit most from what type and frequency of screening.

"Mammography has been provocative over many decades. It's important that women have a better understanding of how mammography is important for them based upon their age and other risk factors," said McCaskill-Stevens.

Explore further: Women prefer getting mammograms every year

Related Stories

Women prefer getting mammograms every year

November 21, 2017
Women prefer to get their mammograms every year, instead of every two years, according to a new study being presented next week at the annual meeting of the Radiological Society of North America (RSNA).

Abbreviated breast MRI may be additional screening option for dense breasts

November 28, 2017
Among women with dense breast tissue, for whom traditional mammograms are less effective at detecting cancer, who request additional screening after a negative mammogram, abbreviated breast MRI (AB-MR) may be a valuable cancer ...

TMIST breast cancer screening trial begins to enroll nearly 165,000 women

September 26, 2017
The Tomosynthesis Mammographic Imaging Screening Trial (TMIST), the first randomized trial to compare two types of digital mammography for breast cancer screening, is now open for enrollment. The study was developed by the ...

Why physicians recommend 3-D mammograms

November 1, 2017
For women over the age of 40, getting a yearly screening mammogram is an essential part of maintaining their breast health. While most mammograms are normal, occasionally a second screening will need to be performed. Getting ...

Task force: Mammograms an option at 40, do more good at 50

January 11, 2016
Mammograms do the most good later in life, a government task force declared Monday in recommending that women get one every other year starting at age 50. It said 40-somethings should make their own choice after weighing ...

Screening with tomosynthesis or ultrasound detects more cancers in dense breasts

March 9, 2016
Adding either tomosynthesis (a form of 3D mammography) or ultrasound scans to standard mammograms can detect breast cancers that would have been missed in women with dense breasts, according to an interim analysis of a trial ...

Recommended for you

From the ashes of a failed pain drug, a new therapeutic path emerges

November 16, 2018
In 2013, renowned Boston Children's Hospital pain researcher Clifford Woolf, MB, BCh, Ph.D., and chemist Kai Johnsson, Ph.D., his fellow co-founder at Quartet Medicine, believed they held the key to non-narcotic pain relief. ...

Repurposing FDA-approved drugs can help fight back breast cancer

November 16, 2018
Screening Food and Drug Administration (FDA)-approved compounds for their ability to stop cancer growth in the lab led to the finding that the drug flunarizine can slow down the growth of triple-negative breast cancer in ...

Traditional chemotherapy superior to new alternative for oropharyngeal cancers

November 16, 2018
A drug increasingly used in combination with radiotherapy to treat a type of cancer that forms in the tonsils or the base of the tongue is inferior to a previously favored option, according to a large, clinical trial led ...

New 'SLICE' tool can massively expand immune system's cancer-fighting repertoire

November 15, 2018
Immunotherapy can cure some cancers that until fairly recently were considered fatal. In addition to developing drugs that boost the immune system's cancer-fighting abilities, scientists are becoming expert at manipulating ...

Anti-malaria drugs have shown promise in treating cancer, and now researchers know why

November 15, 2018
Anti-malaria drugs known as chloroquines have been repurposed to treat cancer for decades, but until now no one knew exactly what the chloroquines were targeting when they attack a tumor. Now, researchers from the Abramson ...

Standard chemotherapy treatment for HPV-positive throat cancer remains the most effective, study finds

November 15, 2018
A new study funded by Cancer Research UK and led by the University of Birmingham has found that the standard chemotherapy used to treat a specific type of throat cancer remains the most effective.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.