Preoperative MRI Reduced Reexcision Rates in Early Breast Cancer

Women who underwent preoperative magnetic resonance imaging (MRI) before undergoing breast conservation therapy had lower reexcision rates than women who did not undergo MRI, according to the results of a study published in the American Journal of Roentgenology.

However, preoperative MRI was not associated with any improvements in recurrence or disease-free survival.

“Because rates of local recurrence are increased among patients with incompletely excised cancer, preoperative MRI has been used to maximize tumor excision within the breast,” wrote Janice S. Sung, MD, of the department of radiology at Memorial Sloan Kettering Cancer Center, and colleagues.  “However, the use of preoperative MRI remains controversial because of conflicting reports on its effect on both surgical and long-term outcomes.”

In order to explore this topic further, Sung and colleagues compared both short-term and long-term outcomes in women with early stage breast cancer matched by surgeon, clinical and histologic features.

This retrospective review included 174 women with early stage breast cancer who underwent preoperative MRI between 2000 and 2004. Short- and long-term outcomes in these women were compared with a control group of 174 women with early breast cancer who did not undergo preoperative MRI. Women were matched by age, histopathologic finding, stage and surgeon. Patients were followed for a median of eight years.

The results showed that patients in the preoperative MRI group were more likely to have dense breasts compared to those women who did not undergo preoperative MRI (28 percent versus 6 percent; P <0.0001). Additionally, these women were also more likely to have mammographically occult cancer (24 percent versus 9 percent; P=0.003).

After surgery, no differences were found between the two groups for final negative margins, lymph node involvement, lymphovascular invasion, extensive intraductal component status, positive hormone-receptor results and systemic adjuvant therapy.

Forty-five percent of patients in the control group required additional surgery compared with 29 percent of patients in the preoperative MRI group (P=0.02).

“A reduction in reexcision rates is potentially beneficial for patients by reducing the emotional anxiety associated with undergoing additional surgical procedures and by improving cosmesis with breast conservation,” the researchers wrote.

However, no difference in local or regional recurrence or in disease-free survival was found between women who underwent preoperative MRI and those who did not.

“To confirm our results, a prospective randomized clinical trial would have to be conducted at institutions performing high-quality breast MRI and where the surgical approach at initial lumpectomy is uniformly linked to the findings detected at breast MRI,” the researchers wrote. “Additional analyses also are needed to determine whether the 15 percent reduction in additional surgical procedures in our study is cost-effective enough to justify the use of preoperative MRI.”