ACS issues guidelines for MRI scanning of breasts

According to new guidelines issued by the American Cancer Society, women with cancer detected in one breast should undergo annual MRI (magnetic resonance imaging) scanning to rule out growth of cancerous tissues in the opposite breast.

The recommendations follow a study that shows MRI scanning to be more sensitive than mammography in detecting tumors in women with an inherited susceptibility to breast cancer.

The new guidelines urge women with a strong family history of the disease or those showing a genetic predisposition or other high-risk factors to undergo MRI breast screening.

Process of using low-dose X-rays to examine the human breast, mammography is used to spot dense masses like tumors.

Unlike mammography, MRI generates more detailed images using magnet and radio waves and can detect cancers that are not visible on mammograms. MRIs are also better at showing increased or abnormal blood flow in the breast, an early sign of cancer but picked up by mammogram.

MRI scans are 90 percent more efficient in detecting cancers in the opposite breast that are invariably missed in ordinary mammograms, a specialized type of X-ray, the study featuring in the New England Journal of Medicine reveals.

The study conducted at the University of Washington Medical Center examined 1,000 women diagnosed with cancer in only one breast.

Not exposed through mammography, MRIs of the second breast found possible tumors in 121 women, while biopsies confirmed cancer in 30 cases, results of the study reports.

However, it is important to note that although Magnetic resonance imaging is 27-36 percent more sensitive than mammography, it is not perfect. MRI scanning is less specific than mammography and carries an error rate of about 5 percent, thereby causing undesirable financial and psychological burdens.

Where, a mammogram costs roughly between $100 and $150, an MRI can cost $2,000 or more at some medical centers.

The new guidelines recommend an annual MRI for breast cancer for women who:

• Have BRCA gene mutation that increases breast cancer risk.

• Are untested for the gene mutation but have a close relative who has it.

• Have an estimated 20 percent or higher lifetime risk for breast cancer based primarily on family history.

• Received radiation therapy to chest for Hodgkin's disease between ages 10-30.

• Have a disease that heightens breast cancer risk, such as Li-Fraumeni and Cowden syndromes.