Getting regular screening mammograms after age 40 is one of the best ways to detect breast cancer early, when it's most treatable. But reading screening mammograms is not a perfect science. Sometimes cancers are missed. And sometimes areas that aren't cancer might be identified as cancer ("false positive"). A study looked at whether certain characteristics of mammogram centers might affect the accuracy of screening mammogram readings.
An accurate reading means that:
- Mammograms of women with breast cancer are read as abnormal, identifying the breast cancer. This type of accuracy is called "sensitivity."
- Mammograms of women without breast cancer are read as normal, meaning no breast cancer is present. This type of accuracy is called "specificity."
- Mammograms read as abnormal have truly identified a breast cancer. This type of accuracy is called "positive predictive value."
Of 44 mammogram centers studied, centers with the following characteristics were more likely to have accurate screening mammogram readings:
- Doing only screening mammograms, not both screening and diagnostic mammograms. A diagnostic mammogram is done to confirm a suspected cancer diagnosis.
- A mammogram reader who specializes in breast imaging, rather than a general radiologist.
- Having only one person read the mammograms. Mammogram centers that had two doctors review mammograms, either together or one after the other, were more likely to have inaccurate readings.
- Doing periodic audits of reading accuracy. This means that staff members check the medical records of women after they had a screening mammogram at that center to see what happened and whether the mammogram readings were accurate.
By better understanding the center characteristics linked to more accurate screening mammogram readings, mammography centers may be able to make changes to improve accuracy. These results also may help doctors recommend a screening mammography center.
Still, it's important to know that other factors not mentioned in this study have been linked to more accurate mammogram readings. One of the most important factors is whether the doctor reading the mammogram has access to previous mammogram images and then compares the new images to the older ones.
Many women in the United States have trouble finding a mammography center that is conveniently located, affordable, and has easy and timely scheduling. In this case, asking center staff members to take any and all steps to make sure the reading is accurate -- such as comparing new images and old images -- may be all that can be done to increase the chances of getting an accurate reading. Women with several mammogram centers to choose from have the option of asking their doctors for a recommendation, based on reading accuracy.
Read more about mammograms and other approaches to breast cancer screening in the Breastcancer.org Screening and Testing section.