Breast MRI and the New American Cancer Society Guidelines for Breast Cancer Detection

Patient Expert

In March 2007, the American Cancer Society announced that breast MRI and mammogram, when used together, give doctors a better chance of finding breast cancer early in high-risk women, when it's easier to treat, when survival outcomes are more hopeful. Learn more about this breast exam.

My technician recently told me, just before sending me gliding through an MRI tube, that MRI scans were once an uncommon breast exam. He performed the breast scans only a few times per month, when radiologists needed to get a better read on potential breast cancers than they could from mammography alone.

Now my tech performs the highly sensitive breast exam, which uses magnetic and radio waves to create layers of black and white breast images, all the time. He told me his MRI suite--with just two machines--now has a companion facility on the same hospital grounds, due to increased demand.

There is more need for breast MRIs, he said, and with the new American Cancer Society (ACS) recommendation--certain women with high risk of developing breast cancer should get MRI scans in addition to their yearly mammogram--it seems the demand for these machines will keep climbing.

In March 2007, the ACS announced that breast MRI and mammogram, when used together, give doctors a better chance of finding breast cancer early in high-risk women, when it's easier to treat, when survival outcomes are more hopeful.

MRI--also known as magnetic resonance imaging--uses a large magnet and radio waves to measure several properties of tissue in the breast. It creates very precise images and can sometimes detect cancers that may never be seen on mammograms. It can miss some cancers too. MRI scans cannot pick up on tiny specks of calcium, also known as microcalcifications, which account for some of the cancers detected on mammograms.

False positives are another downside to MRI. The scans are more likely to show spots in the breast that may not be cancer. Since there is no definite way of knowing whether or not a spot is cancerous, a biopsy or other invasive breast exam procedure becomes necessary. To protect women with average risk of breast cancer from the pitfalls of false positive results, MRI is only recommended for women at high risk for the disease.

These high-risk women--profiled below--should begin getting MRIs and mammograms beginning at age 30, according to the new ACS guidelines.

Women defined as high-risk are as follows:

  • Women with a BRCA1 or BRCA2 gene mutation--this predicts a high likelihood of breast cancer diagnosis.
  • Women with a first-degree relative--parent, sibling, child--with a BRCA1 or BRCA2 mutation.
  • Women with a lifetime breast cancer risk scored at 20 to 25 percent or greater, based on accepted risk assessment tools that consider family history and other factors.
  • Women who had radiation therapy to the chest between the ages of 10 and 30.
  • Women with Li-Fraumeni syndrome, Cowden syndrome, or Bannayan-Riley-Ruvalcaba syndrome, or with a family history of these syndromes.

Breast MRI might be beneficial for other groups of women--those with a lifetime risk of 15 to 20 percent, those with dense breasts, those with a personal history of breast cancer--but there is currently not enough evidence to recommend for or against the scans for these populations.

There is also some evidence that MRI might help detect breast cancer in patients' opposite breasts. Published in the New England Journal of Medicine, a study of 969 newly-diagnosed breast cancer patients turned up 30 opposite-breast early-stage tumors that were not found during physical exams or mammograms. Only three tumors were missed.

It is important to note that some doctors, regardless of evidence and recommendations, may prescribe MRI scans for women they believe would benefit from the screening. I am one such woman--sent by my oncologist to the MRI clinic every six months because he believes my personal history of breast cancer is enough to warrant all testing available. I am happy to submit to every test available. It makes me feel safe to be in the revolving medical system--and in the MRI tube too, despite the cost: about $1,600: $260 of it my patient responsibility.

MRI scans are safe and while the examination may not be advisable for some--those with metal implants, severe lung disease, uncontrollable gastroesophageal reflux, and claustrophobia--they are appropriate for many.

The entire breast MRI experience lasts for about one hour--about half of the time the (potential) breast cancer patient rests on her back and the other half she rests on her stomach, with both breasts hanging freely into cushioned areas. The whole process begins with the placement of all personal belongings--watch, wallet, credit cards with magnetic strips, jewelry--in a secure space. Then the patient dresses in a hospital gown, enters the MRI area, reclines on a flat surface, which is automatically led into a tube. Once the scan begins, a loud thumping sound rings out for bursts of time. Other than the sound, there are no other sensations.

Some MRI scans require an injection of contrast material to help identify certain tissue structures. In this case, the patient is moved out of the tube so an IV can be started. Then it's back into the tube for more noise--and not much else. There is always a panic-type button a patient can press to alert the technician of a problem.

Once the MRI is complete, the patient can resume normal activities. A physician will make contact with test results as soon as they become available.

MRI procedures are evolving every day. In addition to its role in screening, MRI is becoming the latest, greatest alternative to surgical breast biopsy.

Typically used when areas of concern cannot be seen well enough for mammogram or ultrasound-guided biopsy, MRI-guided biopsy allows a doctor to place a needle into a suspicious area and remove a sample that would have been otherwise hard to target. The procedure requires only topical numbing and leaves little scarring. It's quicker, less expensive, and has fewer complications than surgical biopsy. It's another one of the techniques my MRI technician says is becoming more and more common.

Life has changed for my technician whose job is becoming consumed with MRI procedures. He says he thinks this new trend is important. I suspect women at high risk for breast cancer and those in need of swift and painless biopsies would agree.