Mammography Still the 'Gold Standard' for Breast Cancer.
"Many consider [digital mammography] to be a major technical advance over traditional mammography, but studies to date have not demonstrated a meaningful improvement in screening accuracy," the report says. The FDA approved one digital mammography device last year.
Panel member Janet Baum, MD, associate professor of radiology at Harvard Medical School, says the jury's still out on digital mammography.
"It may be better information to some patients [with dense breasts]," Baum tells WebMD.
There also are other alternatives that may prove effective as screening tools, such as high-frequency ultrasound waves that bounce off the tissue and can then be assembled into a map. A new 3-D ultrasound displays tissue in depth, not just a single slice.
Magnetic Resonance Imaging, or MRI, has been used to look inside the body with great accuracy since the mid-80s. Now it might be used to seek out breast tumors that require minimal surgery. Still, this approach may not be as effective in separating out nonmalignant vs. malignant tumors.
For decades, researchers have thought it would be possible to illuminate cancers by shining a light source against the breast and looking at the differences in wave transmission through the tissue. The latest effort involves using techniques that can measure the chemical and molecular components of the breast.
Another option, this one being developed at Harvard, is a handheld scanner that contains pressure scanners that can be moved gently across the breast. The image is generated in as little as 20 seconds without painful compression of the tissue.
To expedite the development of new breast cancer screening approaches, the panel suggests more studies in a variety of areas, with funding coming from several sources. The report also urges Congress to create greater access to mammography through the CDC's screening program. State legislatures also could pick up some of the tab for more poor women through the Medicaid program, the IOM says.
"We're urging that funding be raised to enable them to reach at least 70% of women who don't have access because they have no method of paying," Lashof tells WebMD.
In addition, the IOM wants to see the development of cancer specimen or tumor banks that can help identify genetic changes or biomarkers in breast malignancies at all stages of development. That could lead to a blood test that might eliminate the need for mammography.
The NCI's Kramer says that it's hard to know when to launch a large clinical trial, particularly since new technologies are always being developed. Whatever the machine, he argues that lower mortality is the crucial measure of any screen. "Often the tests are embraced before their medical benefits and harms have been tested," he says.
The panel didn't look at the question of when to begin screening. The federal government currently recommends that women have the procedure every one to two years starting in their 40s. The panel did say, though, that there should be further studies to define more accurately the risks and benefits of mammograms for women over age 70.