Researchers in Chicago and Seattle are advising young women at high genetic risk of developing breast cancer to ditch their annual mammogram in exchange for two MRs every six months.

Presenting their findings at the annual San Antonio Breast Cancer Symposium, the scientists from the University of Chicago Medicine and the University of Washington argued that twice-a-year MR scans are more effective at detecting early breast cancer in women with high-risk genetic profiles than an annual mammogram alone.

"Women with mutations in BRCA1 or BRCA2 have very different needs for surveillance for breast disease than women with no mutations in these genes,” study co-author Mary Claire King, professor of genome sciences and of medicine at the University of Washington and the American Cancer Society Research Professor for Breast Cancer, said in a statement. “This is particularly true for healthy young women with mutations. It's truly critical to offer intensive surveillance to still-healthy women with BRCA1 or BRCA2 mutations."

Annual dynamic contrast-enhanced magnetic resonance scans, along with annual mammograms, are recommended by the American Cancer Society to women at high risk of developing breast cancer, with many advised to begin undergoing exams starting at age 30.

Researchers compared the efficiency of MR to mammography in the cases of 295 women who possessed a greater than 20 percent lifetime risk of developing breast cancer. One of 11 known breast-cancer-related genetic abnormalities was found in 53 percent of enrollees, with 75 percent carrying BRCA1 mutations and 61 possessing BRCA2 mutations. Women diagnosed with breast cancer or ductal carcinoma in situ before 35, or who had a mother or sister diagnosed with breast cancer before age 50 (before 40 for those of African descent) were also included. The mean age for participants at the beginning of the study was 43.3 years.

Participants were subjected to a panel of genetic tests examined by a physician or genetic counselor to identify genes associated with predispositions to breast cancer. A clinical breast exam and a DCE-MR scan were then conducted every six months, as well as a digital mammogram every 12.

Researchers identified four cases of ductal carcinoma in situ and 13 early stage breast cancers, fifteen of which were found in participants with pathogenic mutations. Eleven possessed BRCA1 while three had BRCA2 and one involved CDH1. All cancers detected were smaller than a centimeter with the mean tumor size measured at 0.61 centimeters. Cancer in all cases did not spread to the lymph nodes.

Following this, patients with cancer were followed continuously between six months and 11 years, experiencing decreases in anxiety levels and reporting improvements in their quality of life. All are alive today and free of systemic disease.

Though able to detect invasive breast cancers faster and rule out suspicious abnormalities detected on mammograms due to its higher sensitivity, MR is often too expensive for routine screening, a fact which led 27 percent of patients to withdraw from the study within five years. Other withdrawals were attributed to prophylactic mastectomy, moving away or changes in healthcare providers.

Olufunmilayo Olopade, the Walter L. Palmer Distinguished Service Professor and associate dean for Global Health at the University of Chicago Medical Center, says that further evaluations of this approach may lead to more affordable coverage for MR breast imaging, enabling faster and less invasive, personalized assessments and detection of early stage breast cancer.

"This study demonstrates for the first time that aggressive breast cancers can be caught early, without excessive recalls or biopsies," she said in a statement.

Researchers performed 2,111 DCE-MRs, an average of seven per participant, and 1,223 mammograms, four per participant, citing high levels of surveillance and high-quality care in the prevention of breast cancer in the majority of women, despite most participants carrying genetic mutations. Continual screening was offered to patients who completed five years of study.

Support was provided by the National Cancer Institute; the Dr. Ralph and Marian Falk Medical Research Trust; Susan G. Komen; the Breast Cancer Research Foundation; and the Housewares Charity Foundation.

The findings are available in the journal, Clinical Cancer Research.

Researchers did not respond for comment.