Breast MRI Doesn’t Increase Unnecessary Mastectomies

Increased use of MRI to evaluate newly diagnosed breast cancers has not resulted in an increase in contralateral prophylactic mastectomy (CPM), show findings of a study presented this week at RSNA 2012.

Researchers undertook the study to identify which patient and MR factors were associated with a patient’s decision to undergo CPM. “The 11-fold increase in CPM from 1998 to 2007 and current rate of 5 percent led researchers to theorize that women undergoing numerous breast cancer tests and treatments may choose to remove the other breast as a means of not having to deal with the disease again in the future,” Habib Rahbar, MD, said in a release. Rahbar is an acting assistant professor in the Department of Radiology at the University of Washington, in Seattle.

Researchers reviewed the results of 934 women who were enrolled in the American College of Radiology Imaging Network (ACRIN) 6667 trial, MRI of the Contralateral Breast. All had been newly diagnosed with breast cancer and had undergone an MRI of the opposite breast before surgery.

The results showed that 86 women (9.2 percent) underwent CPM and, compared with those who did not, the CPM group tended to be younger, premenopausal, diagnosed with ductal carcinoma in situ (DCIS), have greater breast density, and have a family history of breast cancer. MRIs that showed possible abnormalities or suggested the need for further follow-up did not have an impact on the decision for CPM.

Considering that the cure rate for DCIS is high, approaching 100 percent, the results are surprising, said Rahbar. “It will be important to conduct additional studies to assess the effects of specific counseling techniques employed with women diagnosed with DCIS, as well as those with dense breasts, in order to better understand the multifactorial decision to undergo CPM,” he added.