Breast MRI – Should all women get this test?

Patients often ask me: “Should I get an MRI?” (magnetic resonance imaging).  The answer from me is: “Only if you need it.” 

Why should we NOT all get breast MRI?  After all, we know that mammograms and ultrasounds do fail to pick up some breast cancers.  MRI is the latest, most expensive modality in breast imaging.  It’s the best, is it not?  Well, clearly, the advantage of MRI is that it can see everything and anything.  The disadvantage of MRI also is that it can see everything and anything.  When an “abnormality” is detected on MRI, sure it could turn out to be breast cancer.  But it can also turn out to be one of the many completely benign conditions, such as fibroadenoma, cyst, fibrocystic, infection, breast engorgement from menses or lactation, bruising from trauma, scar from previous surgery or needle biopsy, previous radiation, etc.  The only sure method of telling cancer from benign is to subject the patient to an invasive biopsy to obtain tissue from the MRI breast abnormality.  So, if you want to get a breast MRI, you should be mentally prepared for the biopsy that will be recommended by your doctor if the MRI shows an “abnormality”.  Because the MRI is so good at seeing everything and anything, there is a good chance that an “abnormality” will be revealed.  Afterwards, we call these benign biopsies unnecessary because the “abnormality” is a false positive finding.  But before the biopsy result comes back as benign, it certainly was very necessary, because no patient and definitely no doctor wants to let an “abnormality” go unchecked.

The answer to who needs an MRI is not always simple.  The current guidelines advise breast MRI for the following women:

1) Lifetime breast cancer risk 25% or higher

2) BRCA (breast cancer gene) carrier

3) First-degree relative of a BRCA carrier, if the first-degree is not tested for the gene

4) Previous radiation to chest between age 10 and 30 (for non-breast cancer reasons)

5) New diagnosis of breast cancer

6) Silicone breast implants

There are certain women who may need a breast MRI, although these women may not meet any of the above criteria.  The decision for a breast MRI should be made jointly with a physician, on an individual patient basis, so that the “pros” and the “cons” can be discussed ahead of time.  It should be emphasized that MRI is an adjunct to mammography, not a replacement.  Normal-risk women age 40 or higher should have yearly mammogram and physical examination.  High-risk women should have an individualized plan, based on the individual’s specific breast cancer risk(s) and other non-breast medical condition(s).