ACS guidelines may be excluding high-risk women from MRI screening

American Cancer Society guidelines call for the use of MRI screening for women based on lifetime risk for breast cancer, but the results of a recent study showed that those guidelines may miss some women with a substantial risk for BRCA mutation.

ACS guidelines recommend MRI for women who are BRCA mutation carriers, the first-degree relatives of BRCA mutation carriers who have not undergone genetic testing and women with a lifetime risk of ≥20% for breast cancer, according to the BRCAPRO breast cancer risk assessment model or other models dependent on family history.

Researchers from Massachusetts General Hospital and the University of Texas set out to determine whether those guidelines excluded other high-risk women.

The researchers conducted a retrospective analysis of 18,190 women who received mammography screening at Massachusetts General Hospital from 2003 to 2005.

Based on BRCAPRO, 78 women in the cohort had a ≥20% lifetime risk for breast cancer. All of those women had a ≥10% risk for carrying a BRCA mutation. Another 374 women had a ≥10% risk for carrying a BRCA mutation but a <20% lifetime risk for breast cancer.

The researchers said BRCAPRO predicted that 27 of the 78 women with a ≥20% lifetime risk for breast cancer would also carry BRCA mutations.

Among 1,035 Jewish patients, 23 had a lifetime risk of ≥20%, including eight predicted to carry BRCA mutations. Another 96 Jewish women had a lifetime risk for breast cancer of <20% but a >10% risk for mutation.

Based on these results, the researchers concluded that, when applied across a large population, the ACS guidelines could exclude a high number of women at high risk for breast cancer. – by Jason Harris

Cancer. 2008;doi:10.1002/cncr.23913.

The ACS has set up guidelines, but those guidelines, if followed strictly, are not necessarily capturing all the patients who are at high risk. The problem is, especially at large institutions, women are receiving more MRIs than ever — patients are walking in and demanding them. What the ACS did in trying to limit the procedure to high-risk patients is a good thing, but their criteria, as Hughes et al suggested, might not be enough. We need to further refine the criteria for when breast MRI is indicated. The researchers brought up a very good point, and additional studies are needed to determine exactly how to define high-risk patients.

– Meena S. Moran

Assistant Professor of Therapeutic Radiology
Yale University School of Medicine