Women with a high genetic risk for breast cancer run a better chance of having it detected with magnetic resonance imaging than with mammography and other methods, researchers said on Tuesday.

The kind of breast cancer involved is caused by mutations of the genes BRCA1 and BRCA2, believed responsible for 5 percent to 10 percent of all breast cancer cases. Women with the mutations have a significantly higher risk of breast cancer.

Researchers at Canada’s Toronto-Sunnybrook Regional Cancer Centre said they studied 236 women with the mutations aged 25 to 65 who underwent annual screenings from 1997 to 2003 using all methods.

They found that 17 cancers in the group were detected by MRI compared to 8 by mammography, 7 by ultrasound and 2 by semiannual clinical breast examinations.

“Our results support the position that MRI-based screening is likely to become the cornerstone of breast cancer surveillance for BRCA1 and BRCA2 mutation carriers, but it is necessary to demonstrate that this surveillance tool lowers breast cancer mortality before it can be recommended for general use,” the report added.

The study was published in this week’s Journal of the American Medical Association, which also carried an editorial by two researchers at Memorial Sloan-Kettering Cancer Center in New York.

The findings combined with another recent study “strongly suggest that women with (these) mutations should be offered such screening,” the commentary said.

But it said women and their doctors should be aware that the results of such screening “may be substantially less than described if different imaging protocols are followed or if experienced radiologists and suitable technology, including the capability to perform magnetic resonance-guided biopsies, are not available.”

SOURCE: Journal of the American Medical Association, September 15, 2004.