Mammograms Not As Good For Second Breast Cancers

Women who have already had breast cancer have a higher risk of getting a second, new breast cancer than other women.  In addition, they are probably seen more often and get more x-rays and mammograms than women who have not had cancer.  Despite this, screening mammograms (mammograms taken to look for unknown problems) are worse at finding new cancers in women who have already had breast cancer, according to a new study in the Journal of the American Medical Association.  According to this large study, mammograms were 10% worse at finding new cancers in breast cancer survivors than in other women.

Mammograms find most of the breast cancers in all women, and  miss some cancers in all women.  However, mammograms performed worse in breast cancer survivors, despite the fact that these women have more evaluations and a higher rate of new cancers. 

Mammograms had detected 76.5 percent of the cancers in women who had never had breast cancer and 65.4 percent in those who had previously had the disease.

This study does not explain why mammograms perform worse in breast cancer survivors, but researchers theorize that the changes that come from surgery and radiation used to treat the first cancer may cause distortions and scarring that may hide new cancers.  Despite having more missed breast cancers, breast cancer survivors in this study actually had more biopsies than women without a history of breast cancer.

Women who have had breast cancer should most definitely continue to get yearly screening mammograms; that is still the best way to find a new cancer in early stages. Further studies will be needed before additional testing can be recommended on a routine basis for breast cancer survivors.

The study “does raise the question, however, as to whether supplemental screening with other modalities, notably ultrasound or MRI, is appropriate in a certain subset of these women,” according to Carol Lee, MD, chair of the American College of Radiology’s commission on breast imaging. “However, this study does not directly address that question.”

Both breast cancer survivors and the physicians who care for them need to remain vigilent to detect new cancers.