After cancers of the skin, breast cancer is the most common cancer among women, accounting for nearly one in four cancers diagnosed in American women today. Breast cancer death rates are higher than those for any other cancer besides lung cancer. For women ages 40 to 59, the main cause of death is cancer of the breast.
Although these statistics are sobering, breast cancer death rates have declined by almost 20% over the past decade, in part due to increased screening for breast cancer, which typically uncovers the disease at a time when the chance for successful treatment is higher.
Several imaging techniques can detect breast lumps before a woman or her doctor can feel them. Mammography, which allows doctors to uncover an abnormal breast mass up to two years before it can be detected by touch, remains the gold standard imaging technique for breast cancer.
Mammography relies on a two-dimensional x-ray image. However, this technology has limitations because the female breast is three-dimensional and composed of different structures—including milk ducts, blood vessels, and ligaments—located at various levels within it. When scanned and viewed as a flat, two-dimensional image, the mammography scan can be confusing to interpret and doesn’t always reveal every cancer. This confusion is a major reason why normal tissue may appear abnormal and why small breast cancers may be missed.
There is now a new imaging technology that is changing the way doctors screen for breast cancer and it is improving the accuracy of diagnosis. Called breast tomosynthesis or 3D mammography, the diagnostic technology was approved by the Food and Drug Administration in 2011. Breast tomosynthesis does not currently replace traditional two-dimensional mammography testing but instead it is preformed at this time along with the conventional mammogram to provide a more accurate view of the breast.
During the tomosynthesis portion of the exam, the x-ray arm of the machine makes a quick arc over the breast, taking dozens of images at a number of angles. Later combined to make a three-dimensional rendering of the entire breast, the images can be viewed by a radiologist at a computer workstation to check areas of concern.
If cancers are found when they are small, treatment options are generally less traumatic and the chance for cure is greater. What 3D technology offers doctors and mammography technicians is a much greater opportunity to discover small cancer cells obscured by surrounding tissue that may not be visible on standard mammograms. This is particularly the case in women with dense breasts, in which tumors often escape detection. Preliminary study results of 25,000 women reported a 47% increase in cancer detection when tomosynthesis was used.
3D mammography also reduces the much-feared callbacks for women. Due to a lack of diagnostic clarity, one in 10 women typically is asked to return for additional testing following a routine mammogram screening that has raised concern. However, in a recent study of 7,500 women, the recall rate of women screened with breast tomosynthesis and traditional mammography combined was 6.6% compared to 11.1% for traditional mammography alone.
It’s for reasons like this and others that one day, in response to greater use and patient demand, experts believe that breast tomosynthesis is expected to fully replace conventional mammography.
Where Are They Now
There are now three different devices that can provide 3D breast imaging available to consumers in the US. Quick adoption, fewer recalls, and simultaneous market penetration have supported the market growth. However, integration of this new technology has been slow due to the lack of reimbursement from most insurance agencies and lack of a standard approach to acquiring these 3D images, despite its continued superiority over the current standard of 2D imaging. In 2017, the state of Texas issued legislation requiring commercial insurance providers to cover breast tomosynthesis, in addition to the covered 2-D version. Enactment of this legislation could move the country in a direction toward more widespread adoption and utilization of the technology.