Hutch News

More is not always better

New U.S. Preventive Services Task Force breast cancer screening guidelines seek to balance risk, benefit

Jan. 11, 2016
Breast screening

New breast cancer screening guidelines released by the U.S. Preventive Services Task Force are designed to balance mammography's benefits, that is, catching cancer early when it is easiest to treat, with its potential harms.

Getty Images file

Yes, you heard correctly. Another big set of breast screening guidelines is out this week, this one from the U.S. Preventive Services Task Force.

As with the guidelines released by the American Cancer Society last October, the Task Force guidelines are designed to balance mammography’s benefits (catching cancer early, when it is more treatable) with its potential harms: unnecessary biopsies, false positives that can freak women out, and overdiagnosis — leading to overtreating women who don’t actually have a deadly or dangerous form of the cancer.

For women inundated with recommendations regarding their breast health, there’s good news: the two sets of guidelines — both of them geared towards average-risk women with no symptoms — have more in common in their latest iteration than ever. In a nutshell, both the Task Force and the ACS are leaning towards a “less is more” philosophy with regard to mammography, with the Task Force opting for a little less screening than the ACS.  

Here’s a quick breakdown of the Task Force’s finalized guidelines, published Monday:

  • Women 50 to 74 years old should get mammograms every other year (the ACS suggests yearly exams for woman ages 45-54 and exams every other year after that).
  • If women want to start getting mammograms every other year at age 40, they are welcome to do so. The ACS’s guidelines are cool with that, too, although they recommend mammograms every year for younger women. Again, both organizations acknowledge the importance of individual choice.
  • There’s not enough evidence to know if mammograms after age 75 are more beneficial or more harmful overall. (The ACS suggests women continue to get mammograms as long as their health is good and they have a life expectancy of 10 years or longer.)
  • There’s also not enough evidence to make a recommendation for the use of 3D tomosynthesis instead of regular 2D mammography for breast screening, or to make a recommendation about using additional screening like ultrasound, MRI, 3D tomosynthesis, etc., for women with dense breasts. The ACS didn’t make any recommendations regarding 3D tomosynthesis or additional breast screening for dense breasts.

In 2009, the Task Force first recommended that mammograms start at age 50 rather than 40, spurring a heated national debate and prompting Congress to pass legislation ensuring mammograms would still be covered by insurance if women got them starting at age 40.

'Tailored screening'

Dr. Janie Lee, director of breast imaging at Seattle Cancer Care Alliance, said the new Task Force guidelines are similar to the 2009 version, but take a more “nuanced” view of individual women’s decisions, emphasizing the need for a more “tailored breast cancer screening based on risk and patient values.”  

“This update brings the recent recommendations of the [Task Force] and of the American Cancer Society closer together than they were in 2009,” she said. “It’s a tremendous step forward to recognize that the best screening option may be different from one woman to another. It reflects a shift away from a ‘one size fits all’ approach.”

Lee said the new guidelines confirm that regular screening with mammography saves lives and also recognize that a woman’s values will influence what is the best decision for her. In 2009, the emphasis was on the greater benefit for women in their 50s and 60s, she said, compared to women in their 40s. 

“Now the [Task Force] also recognizes that when women are making decisions about when to start screening, the women who focus most on receiving the benefits of screening will choose to start earlier, perhaps in their 40s, or to screen annually after they begin screening,” she said. 

Generally speaking, breast cancers in premenopausal women tend to be more aggressive and faster growing, while those found in older women, past menopause, are slower-growing.  So women, particularly those in their 40s and early 50s, have to weigh for themselves what’s most important to them. Screen early and often and there’s a better chance they’ll catch a cancer early (the benefit); unfortunately, they’ll also bump up their chance of false-positive biopsies and overtreatment (the harm).

Dr. Julie Gralow, a clinical researcher with Fred Hutchinson Cancer Research Center and breast cancer oncologist at SCCA, the Hutch’s treatment arm, emphasized that both sets of guidelines are designed for average-risk women.

“They’re irrelevant for people with a strong family history of cancer, who’ve already had breast cancer, who’ve had biopsies that show something that could lead to breast cancer or who’ve had radiation to treat something like lymphoma,” she said.

Gralow, as well as SCCA, follows the American Cancer Society’s approach of annual mammograms from age 45 to 54 with screening every other year after that.

Dr. Christoph Lee, an SCCA radiologist and public health researcher with the Hutchinson Institute for Cancer Outcomes Research, said the new approach taken by the two sets of guidelines stems from a better understanding of both the benefits and harms of mammography.

“Everyone agrees that screening mammography saves lives but what’s becoming more and more apparent is that for a minority of women, screening mammography also causes some harm,” he said, citing false positives, biopsies, overtreatment and increased radiation exposure from additional and unnecessary mammography. 

Another reason 'less is more'

And according to a new modeling study published Monday in the journal Annals of Internal Medicine by Lee and others, too many mammograms could put certain women at a slightly elevated risk for breast cancer.

Researchers from SCCA, the University of California Davis School of Medicine, the Group Health Research Institute in Seattle and other institutions, used simulation models for breast cancer risk from radiation exposure to estimate how many women could get radiation-induced breast cancer from a variety of screening approaches — including mammography.

The bottom line? Digital mammograms posed a very small risk for most women, and the benefits of screening still outweigh the risks. Screening annually starting at age 40 — as past guidelines had recommended — prevents 968 breast cancer deaths for every 100,000 women and is projected to induce 16 deaths from radiation-induced cancer, their model found. Starting regular screening mammograms every other year at age 50, as the new Task Force guidelines recommend, would drop the risk for those extra cancers fivefold.

Lee said it all had to do with the amount of radiation the women received.

“Think about it logically,” he said. “If you start having mammograms later or you screen less often, you’re exposed to less radiation so there’s less radiation-induced cancer.”

The risk of radiation-induced breast cancer was also slightly higher for women with larger breasts and those with breast implants. While most women get four images taken per mammogram, women with larger breasts may require more to cover the entire area.

Although the research team didn’t explicitly set up a modeling scenario for women with breast implants, Lee said these women receive “double the amount of projections and views during mammograms as the average woman” so were also at potential risk.

However, he also emphasized the overall safety of the screening procedure.

“Mammography is a very safe technology,” he said. “We’re well under the limit set by the government for maximum threshold for radiation exposure even with additional views. This should not be a large concern for women.”

Change in your breast? Get it checked out!

Although safe, the experts agreed that mammography was imperfect.

“It’s the best tool we have but it’s far from perfect,” said Gralow. “We do need better screening methods and we also need to figure out how to diagnose the aggressive breast cancers where it does matter and back off the quiet ones [such as some ductal carcinomas in situ, a noninvasive form of breast cancer] where it’s never going to be a problem.”

Gralow and Drs. Christoph and Janie Lee also stressed how crucial it was for women to discuss the various screening options with their health care providers. Equally important: being breast-aware.

“No one knows your breasts and your body better than yourself,” said Gralow. “So if you find anything worrisome — a lump, a thickening of the skin, a spot where the skin looks a little puckered, anything weird in the armpit or the nipple — get it checked out right away. That is one way to get early detection of breast cancer. Mammography isn’t the only way.”

What do you think about the new mammogram guidelines? Tell us on Facebook.

Diane Mapes is a staff writer at Fred Hutchinson Cancer Research Center. She has written extensively about health issues for NBC News, TODAY, CNN, MSN, Seattle Magazine and other publications. A breast cancer survivor, she also writes the breast cancer blog doublewhammied.com. Reach her at dmapes@fredhutch.org.

Are you interested in reprinting or republishing this story? Be our guest! We want to help connect people with the information they need. We just ask that you link back to the original article, preserve the author’s byline and refrain from making edits that alter the original context. Questions? Email senior writer/editor Linda Dahlstrom at ldahlstr@fredhutch.org.

Solid tumors, such as those of the breast, are the focus of Solid Tumor Translational Research, a network comprised of Fred Hutchinson Cancer Research Center, UW Medicine and Seattle Cancer Care Alliance. STTR is bridging laboratory sciences and patient care to provide the most precise treatment options for patients with solid tumor cancers.


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