In Most Cases, MRI Not Indicated for Breast Cancer Screening

Q:  I'm still getting yearly screening mammograms, but I heard that breast MRIs are better at detecting breast cancer and have a lower radiation level than mammograms.

Should I start getting yearly MRIs instead?

A:  Breast MRIs have very limited indications and have not been approved as a screening modality for most patients.

Screening MRIs are only indicated for those who are considered very high risk. You are considered high risk if you have a known gene mutation that significantly increases the risk for breast cancer (BRCA 1 or 2), if you are a probable carrier of this gene because of family history, or if you have a calculated lifetime risk of breast cancer greater than 20-25% (this is something your doctor can calculate for you).

"For most women at high risk, screening with MRI and mammograms should begin at age 30 years and continue for as long as a woman is in good health," according to the American Cancer Society. "But because the evidence is limited regarding the best age at which to start screening, this decision should be based on shared decision making between patients and their health care providers, taking into account personal circumstances and preferences."

The American Cancer Society also states that women who have received radiation to their chest for Hodgkins disease may be candidates for screening breast MRIs.

Most often, the screening MRI is still combined with the mammogram in these higher-risk patients.

MRIs are quite costly, so it is important to check with your doctor to make sure you meet the indications for a screening MRI prior to having one completed or you could be stuck with a very large bill if your insurance company does not cover it.

Fear of radiation should not stop you from getting regular mammograms. Studies have shown that the screening benefit of yearly mammograms far outweighs the risk of adverse effects from the amount of radiation you receive during the test.

Deidre L. Faust, MD, is a Staff Physician (Internal Medicine) at the Medical College of Wisconsin's Plank Road Clinic. Her column appears in the Milwaukee Journal-Sentinel.