Breast self-exam and screening mammograms are two of the best tools available to diagnose breast cancer early, when it's most treatable. Still, mammograms aren't perfect. Mammograms can identify an abnormality that looks like a cancer, but turns out to be normal. This "false alarm" is called a false positive. False positives usually require more testing, and sometimes a biopsy.
A study found that when a radiologist compares the most recent mammogram with earlier mammograms, false positives can be reduced by 44%. The key was to ALWAYS compare current and earlier mammograms, instead of comparing mammograms only when the radiologist thinks it might help. Comparing mammograms also can help radiologists identify problem areas that might otherwise be missed, but this study didn't address that issue.
The shift from film mammograms to digital mammograms may make it difficult for radiologists to compare mammograms, at least for a little while. But in time digital mammography should make it easier for earlier mammograms to be available for comparison. This is because the images are stored electronically on a computer (rather than on film) and could be retrieved anytime and anywhere.
What can you do to decrease the risk of a false positive? Speak up. When you get your mammogram, tell the technician or radiologist that you want to be sure the images are compared with earlier mammograms. If you're getting your mammogram in a different place than before, talk to the staff to make sure they have access to your earlier images. When you get your results, ask whether they were compared with your earlier mammograms. If there was no comparison, talk to your doctor to make sure it's done.
The National Digital Medical Archive has a service called myNDMA. This service allows women to electronically save digital medical images, including digital mammograms, in a secure place. The images can be made available, with your permission, for retrieval and review by doctors.