BREAST CANCER MRI hailed for some high-risk cases

The study involved women with one of two particular genetic flaws.
LONG ISLAND NEWSDAY
For women who carry either of two genetic flaws known to lead to breast cancer, an MRI is far more accurate in the detection than other screening methods, including mammography, researchers are reporting today.
The finding, in the Journal of the American Medical Association, is being hailed as significant because women with mutations in genes known as BRCA1 and BRCA2 have a higher lifetime risk than the general population. The risk has been estimated as high as 85 percent from age 25 onward.
But use of an MRI "is not for the general population," said Dr. Ellen Warner, lead investigator of the study. Women with the genetic predisposition undergo annual screening and clinical breast examinations starting at age 25. Even with such surveillance, sometimes tumors are found at an advanced stage, she said. An estimated 10 percent to 15 percent of all breast cancer cases involve BRCA1 and BRCA2 mutations.
The high sensitivity of magnetic resonance imaging could improve early detection for this population, for whom prophylactic mastectomy is the only other option, said Dr. Warner, an oncologist at the Toronto Sunnybrook Regional Cancer Centre.
Support for MRIs
Drs. Mark E. Robson and Kenneth Offit of Memorial Sloan-Kettering Cancer Center in New York City wrote in a journal editorial that the findings suggest women at risk should be screened using MRI.
"A technology assessment by one large insurance carrier has already supported the rationale for MRI screening of BRCA mutation carriers and other women at high hereditary risk of breast cancer," the doctors wrote.
Dr. Melanie Palomares, a cancer specialist in the department of clinical genetics at the City of Hope National Cancer Center in Duarte, Calif., said specialists there already use MRI as the primary screening tool for women at high risk. But because it also finds a high number of "false positives," which can lead to unnecessary biopsies, it is not used for the general population.
MRI's high degree of resolution makes it valuable for high-risk women, she said, because abnormalities found usually are cancer.
The study included 236 women ages 25 to 65 with BRCA1 or BRCA2 mutations who underwent one to three annual screening examinations involving MRI, mammography and ultrasound. During the study, 22 cancers were detected. Of these, 77 percent were spotted by MRI, 36 percent by mammography and 33 percent by ultrasound. Only 9.1 percent were found by clinical breast examination.