A better detector for breast cancer

Compared to mammography and ultrasound, screening with MRI allows detection of more breast cancers in high-risk women

Photo courtesy of the University of Washington Dr. Connie Lehman was lead author of a study that found magnetic-resonance imaging is the best breast-imaging tool currently available for detecting cancer.

Magnetic-resonance imaging enables radiologists to accurately identify tumors missed by mammography and ultrasound, according to a multi-center study comparing the three screening methods in women at high risk for breast cancer. The findings of the study appear in the August issue of the journal Radiology.

"Women at high risk for breast cancer can benefit from undergoing screening MRI," said the study's lead author, Dr. Connie Lehman, director of radiology at the Seattle Cancer Care Alliance and professor of radiology at the University of Washington School of Medicine. "Of all the breast-imaging tools we have currently available, MRI is clearly the best at detecting cancer."

According to the National Cancer Institute, genetic predisposition accounts for five percent to 10 percent of all breast cancers. Women who are genetically at high risk for breast cancer need to begin screening at a younger age, because they often develop cancer earlier than women at average risk. However, women below age 50 are more likely to have dense breast tissue, which can limit the effectiveness of mammography as a screening tool. The American Cancer Society recommends that women with a high risk of developing breast cancer should be screened with MRI in addition to their yearly mammogram beginning at age 30.

"It is frightening to be told that you're at very high risk for developing breast cancer," Lehman said. "It's important that these women understand that there is something they can do to increase their chances of early detection in the event that they do develop breast cancer."

Based on their findings, the researchers estimate that, compared to mammography and ultrasound, screening with MRI will allow detection of 23 more cancers per 1,000 high-risk women screened.

While MRI has been shown to be an effective screening tool for women genetically predisposed to developing breast cancer, there is no evidence to support MRI screening in average-risk women. "Although MRI is a very powerful tool for detecting cancer, it is not perfect," Lehman said. "There are benign areas of breast tissue that can look suspicious but do not represent breast cancer and yet may lead to a biopsy."

The International Breast MRI Consortium and the Cancer Genetics Network funded the study.

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