3D Mammography Becoming Standard in Breast Cancer Screening, But Caution Advised

Constance D. Lehman, MD, PhD

Tomosynthesis, otherwise known as 3D mammography, is already recognized as the new standard of care in terms of breast cancer screening, explains Constance D. Lehman, MD, PhD.

However, she cautions that although the advanced technology enables closer examination of tissue and detects more cancers, oncologists should not become overly aggressive in treating patients.

“I think 3D mammography is the new mammography, with the synthetic views where you take those slices and create a 2D-like view,” Lehman says. “Everybody will be using it.” She said oncologists need to leverage the ability this gives them to see tissue better and adjust the ways they respond to lesions found on the 3D mammograms. Lehman is a professor of radiology and chief of Breast Imaging in the Department of Radiology at Massachusetts General Hospital.

Accurate Tomosynthesis Is Essential

Tomosynthesis can improve performance by improving both specificity and sensitivity, but the technology is associated with roughly twice the radiation of 2D mammography. “It is still an X-ray; it’s still a mammogram,” says Lehman. “The mammography unit looks identical, and it can take both 2D and 3D views.” This approach is early in evaluation and appears promising, Lehman says. The transition to tomosynthesis mammography also provides an opportunity to reassess or even challenge current paradigms for diagnostic evaluations of mammographic lesions, she says.However, Lehman says it is important for radiologists to accurately perform tomosynthesis so that patients do not end up overdiagnosed or overtreated.

Though the number of callbacks for repeat mammograms has decreased with the use of 3D mammography, the number of biopsies has not, she adds.

“Everyone is very excited because tomosynthesis finds more cancer,” says Lehman. “Overall, it can do that with fewer false positives. But, here’s the problem. There are fewer recalls with tomosynthesis, as there are more views of the breast being examined in one screening; however, the rate of biopsies has not decreased with the new technology, Lehman adds.

Patient populations who would be most appropriate for tomosynthesis have not yet been determined, Lehman says, adding that the belief that only women with dense breasts should have it is not entirely accurate. “It’s a little bit like when we moved from film-screen (mammography) to digital. Should you get digital? Yes, you should, and it’s a better tool,” says Lehman. “You just have to figure out how to manage it and work with it.”

Lehman’s biggest concern surrounding the technology is the possibility of surgical oncologists doing more excisions, and aggressively treating very low risk cancers. “We’re going to be misleading ourselves. We’re not looking at the full patient experience,” she says. “With MRI, we’re like, ‘this is great. We’re finding more cancer at an acceptable recall rate.’ But if you continue to follow that patient, you realize it’s creating more harm than benefit, so we really have to do the full cycle of patient care, and not just focus on whether the test was positive or negative.”

A multidisciplinary approach, involving the participation of members of radiology, surgery, and primary care, is needed for the management of patients following their 3D mammograms.

“In the 3D era, we don’t have to be as aggressive, but we need to be communicating. We need to have patients share in the decision-making. This includes offering them surveillance versus intervention. If we view them in the right way, collaboratively, so patients aren’t confused, I think we can have a really good paradigm for management of patients in the 3D era.” 3D mammography will likely play a prominent role as part of regular breast cancer screening, Lehman says.

In addition to mammography, magnetic-resonance imaging (MRI) is another screening tool, but one perhaps not appropriately used for detecting breast cancers. Lehman gave the lecture, “Rational Use of MRI in Routine Clinical Practice,” during Friday’s Surgical Track session.

“MRI can detect more cancers than we can see on mammography, ultrasound, or the combination of mammography and ultrasound,” says Lehman. “The challenge is, while we know it performs best in finding cancer, we need to better understand the actual impact on the patient.”

Concerns have been raised about the use of MRI and how it may lead to unnecessary treatment, she adds. “We’re worried that we are almost finding cancers too early, and we’re over treating,” Lehman says. “What about the patient who has just been diagnosed with breast cancer? It is all over the map whether those women get an MRI or not,” says Lehman. “It is so important that there is a multidisciplinary approach. It’s not just getting the MRI. It’s how they work together to decide how the breast MRI information is used and to make sure that it is not misused.”

And along with controversy surrounding aggressive treatment from cancers detected via tomosynthesis and MRI, opinions also vary widely on when women should undergo breast screening.

In their final set of breast cancer screening guidelines, the US Preventative Services Task Force recognized “adequate evidence” that mammography screening has reduced breast cancer mortality, but maintained that most of the benefit for women at average risk for breast cancer is derived by those aged 50 to 74 years who undergo screening every 2 years.

Though there is “astounding agreement” that screening mammography saves lives, Lehman adds there is, truly, a never-ending controversy over when and how often women should be screening.

“I have these discussions with women all the time. If they want to maximize the chance of early detection upfront, an annual mammogram started at 40 makes good sense. If it’s a woman who says, ‘I have no risk factors. I’m worried about all of these tests that I’m having. I just feel that I’d like to wait until 45 or 50. I talk to my doctor and she thinks that it’s a really good idea that I have a mammogram at least every 2 years starting at age 50.’ That’s fantastic, that’s great.”

In relation to the guideline recommendations, Lehman suggests experts focus on the agreement that mammography is a significantly important screening tool, and to engage and educate women on their options—with an individualized approach.

“I think that the more multiple disciplines to take and the more women who can talk together and clarify what they all agree on, the better off our patients are.”