Six Questions to Ask About Mammograms

Regular mammograms are the best way to detect breast cancer at the earliest possible stage. Mammograms identify cancer before symptoms (such as feeling a lump) occur. Early cancers found on a mammogram are often small, confined to the breast (meaning they haven’t spread to other areas), and can be the easiest to treat.

Recently, questions arose about whether the benefits of mammography outweigh some possible risks. Mammograms can identify abnormalities that are not cancer. This can result in additional testing, visits, and sometimes procedures, which can cause stress and anxiety. Mammography also exposes women to a small amount of radiation.

In response, a U.S. task force convened to evaluate research related to breast cancer screening. They announced, and some professional organizations agreed, that women don’t need to start regular mammograms until age 45 or even 50. And, rather than have screenings every year, the new guidelines recommended mammograms every other year for some women, depending on their age and breast cancer risk.

The latest guidelines caused an uproar among women and doctors who believe screening mammograms save lives. Duke radiologist Jay Baker, MD, strongly agrees that screening is beneficial. He said the new guidelines underestimate the value of early detection and overestimate the risk of potential harm. 

If you are at average risk for breast cancer, Dr. Baker said screening should start at age 40. “The most lives and the most years of life are saved by starting screening at age 40,” he said.

According to the Society for Breast Imaging, breast cancer risk starts increasing around age 40. One in six breast cancers occurs in women between the ages of 40 and 49. And, a 2014 study found that most women in their 40s who developed breast cancer were not considered at high risk. Ninety percent of patients had no family history of breast cancer, and 86% did not have dense breast tissue, which is also a risk factor for breast cancer.  Other studies confirm that about 30% of the total years of life lost to breast cancer are from women who were diagnosed in their 40s.

Bottom line: Start regular mammograms at age 40. If you feel a lump in your breast, schedule a mammogram immediately, no matter your age.

Annual screening saves lives and results in a 25 to 40% decrease in lives lost, said Dr. Baker. The Society for Breast Imaging reports that the longest running breast screening trials in history show that regular mammography screening – meaning once a year --- cuts breast cancer deaths by almost a third in all women age 40 and over.

Annual mammograms are also important If you have been told you are at high risk for breast cancer – either because of a family history, because you have been told you have dense breasts, or because you have a genetic mutation such as BRCA 1 or 2.

Bottom line: Annual mammograms increase the likelihood of catching breast cancer at the earliest stage and reduce the risk of dying prematurely of breast cancer.

While some data suggest women over age 74 no longer need mammograms, Dr. Baker said most of the research has simply not included women 75 years and older. Rather, he said research shows there are benefits to annual screening mammograms as long as you are in good health, and have about eight to ten years of life expectancy.

Bottom line: Continue annual mammograms as long as you are healthy and have several good years of life ahead.

Three-dimensional mammography, also known as breast tomosynthesis, is a new form of digital mammography. Unlike standard digital mammograms, which create a two-dimensional view from the top and sides of your breast tissue, 3D mammograms take image slices from many angles. A computer then reconstructs those slices into a 3D image of your breast.

Research indicates 3D mammograms find 15 to 30% more breast cancers, and result in up to 40% fewer false positive results. Data also shows 3D mammography does a better job at finding breast cancer in dense breast tissue.

3D mammography is available at the Duke Cancer Center in Durham and Duke Women’s Cancer Care in Raleigh. Check with your insurance company as there may be an out of pocket expense associated with 3D mammography.

Bottom line: Talk to your doctor about whether you will benefit from a 3D mammogram. 

Duke offers mammography in several convenient locations. Saturday appointments are also available. When choosing where to have your mammogram, consider whether the doctors reading your screens are dedicated breast imaging radiologists. Data show breast imaging radiologists find more breast cancer and have fewer false positives.