As the dust settles -- or doesn’t -- following the new breast cancer screening recommendations released by the U.S. Preventive Services Task Force (USPSTF) last November, physicians may not be advising patients much differently than before.

Thomas F. Koinis, MDThomas Koinis, MD, a Duke primary care physician who chairs the Commission on Health of the Public and Science for the American Academy of Family Physicians (AAFP), says what he’s seeing is that most physicians are following the guidelines of the organization they feel most comfortable with -- whether that’s USPSTF, the American Cancer Society, or the World Health Organization.

And so far there’s no indication that the USPSTF recommendations are curbing insurance coverage or medicare reimbursement of mammograms for women in their 40s.

Paul Kelly Marcom, MDBut the task force revisions raise valid concerns about the current limitations of mammography. “When you strip away the patina of emotion, the issue is that we’re still in the very early days of screening, not just for breast cancer but all cancers,” says Duke oncologist P. Kelly Marcom, MD.

“And if all the women in the United States actually did what was recommended for breast screening, there wouldn’t be enough radiologists to do the mammograms and read them. So we need to figure out how to use our resources more effectively, so that we are screening the women who need it and not the women who don’t.”

Most agree the current debate over the most appropriate age to begin breast cancer screening will be resolved by better identifying which individuals are at high risk -- and by advances in imaging technologies.

What’s most needed is a reduction in false-positive readings, which are more common among women ages 40 to 49 than in older women and are cited as a rationale for changing the USPSTF recommendations. (The breast tissue in younger women is often denser than that of older women, posing more difficulty in imaging.)

Jay A. Baker, MD“Nationally, about 80 percent of biopsies we conduct [based on mammogram results] are benign,” says Jay Baker, MD, chief of breast imaging at Duke, where the rate is about 65 to 75 percent.

“We know we could be doing a whole lot better in reducing unnecessary biopsies,” Baker says, “but radiologists are expected to pick up 100 percent of cancers, and the current culture dictates that we call back even the things we are certain aren’t going to be cancer.”

He says preliminary Duke studies (not yet published) suggest that removing such an unspoken mandate could eliminate as much as 40 percent of the false-positive recalls, while missing virtually none of the cancers.

Though there are many radiologists who call back as many as 10 to 15 percent of their cases for further investigation, Baker says that most research shows that “once you get past a recall rate of about 5 percent, you’re not catching more cancers -- you’re just calling more people back.”

While mammography remains the standard of care, researchers at Duke and other institutions are examining a variety of new and/or improved imaging technology, such as:

• Tomosynthesis. According to Baker, this technology is well on its way to complement and perhaps even replace mammography -- because it is mammography, in a sense. It’s a digital mammogram machine that has been modified to move in an arc over the breast to collect a series -- say, 25 -- of low-radiation images. The result is like a mix of a mammogram and a CT, providing better-quality, multi-dimensional images without more radiation. Early testing of the technology has been promising, but not conclusive, and it’s not yet approved by the FDA.
• Breast ultrasound and breast MRI. Both of these technologies are widely available, but not quite ready for widespread application as screening tools. The false-positive rates for ultrasound are 10 to 1, compared to 4 to 1 with mammogram. The high cost of MRI also makes it a poor choice for widespread use, though both MRI and ultrasound can help refine diagnosis in women at high risk or who have a lesion.
• Breast SPECT-CT (single photon emission computed tomography combined with computed tomography). Developed at Duke by Martin Tornai, PhD, this new machine is an ultra low-dose CT scanner that’s been miniaturized and tailored specifically to image the breast. It provides high-resolution 3-D imaging that can even register biochemical changes -- meaning that it could detect abnormalities much earlier than MRI. The SPECT component requires injection with radioactive dye, so it may only be appropriate for high-risk patients.
• Decision integration tools, also known as CAD (computer-assisted diagnosis). Because computers can store thousands of images of breast lesions, as well as information about whether those lesions turned out to be cancerous, this developing information technology could provide radiologists with a tool to refine their evaluation of breast images by comparing a new scan to a compendium of similar cases.

USPSTF Recommended Screening Guidelines

On November 16, 2009, the U.S. Preventive Services Task Force (USPSTF) recommended new guidelines on screening for breast cancer, including mammography and breast self- exams.

The controversial guidelines, in a reversal from previous recommendations (and the recommendations of several other groups), say the decision to start regular, biennial screening mammography before the age of 50 should be an individual one and take into account the patient’s risk factors and family history. They recommend regular screening, every other year, for all women between the ages of 50 and 74.