MRIs May Drive More Women to Mastectomy

May 16, 2008— -- Women with breast cancer are increasingly opting for mastectomies over lumpectomies, a surgical procedure that removes only the cancerous tumor inside the breast, say researchers at the Mayo Clinic in Rochester, Minn.

The possibility that the growing use of magnetic resonance imaging for diagnosis is partly responsible for this increase is raising new concern over whether women are getting mastectomies needlessly. One leading breast cancer specialist called the MRI-driven boost in mastectomies "alarming."

Mayo Clinic researchers evaluated mastectomy rates at their institution between 1997 and 2006 in relation to the use of preoperative MRI -- a screening tool that is more sensitive than traditional mammography but also more likely to result in false positives for breast cancer.

Researchers sought to answer the question of whether the more sensitive MRI screening test would cause more breast cancer patients, frightened by the lumps and bumps this test picked up inside their breasts, to have the whole breast removed rather than just those lumps that were determined to be cancerous.

They found that among 5,464 women who had surgery for early-stage breast cancer, the mastectomy rates rose between 2003 and 2006, when the number of patients receiving an MRI doubled from 11 percent in 2003 to 22 percent in 2006.

The researchers reported that the number of mastectomies performed at their institution have increased by 13 percent over a period of three years. In 2003, researchers reported that mastectomy accounted for only 30 percent of early-stage breast cancer surgeries. The number rose to account for 43 percent of all breast cancer surgeries in 2006.

Moreover, researchers found that women who received an MRI to screen for breast cancer were significantly more likely to choose a mastectomy than those who did not receive an MRI. More than half of the patients who received an MRI -- 52 percent -- chose to undergo a mastectomy, compared with 38 percent of patients who did not have an MRI.