Characteristics of multifocal and multicentric breast cancers detetected by preoperative MRI.

Abstract

67 Background: Many newly diagnosed breast cancer patients undergo preoperative MRI to define the extent of their disease, as well as to evaluate the contralateral breast. The purpose of this study was to determine the number of patients who were diagnosed with a second malignancy detected solely on MRI at our institution, to compare them to a control group of patients who had an MRI not leading to a diagnosis of cancer, and to compare tumor characteristics of the primary and secondary tumors. Methods: A breast center database was searched for all newly diagnosed breast cancer patients who underwent preoperative MRI from January 2005 to March 2010. Among those who were diagnosed with a biopsy-proven second malignancy based on suspicious MRI findings, pathology and imaging reports were reviewed and data regarding patients and tumors was collected. Results: Out of 624 patients with newly diagnosed breast cancer who had a preoperative MRI, 53 (8.5%) had a second tumor identified solely by MRI. Of these, 40 were ipsilateral, 12 were contralateral, and 1 bilateral. Thirty seven percent were multifocal and 56% were multicentric. Patients who had an MRI were younger than those who didn’t, but there was no difference by age or race for those who had a second tumor found compared to those who didn’t. Tumor size, nodal status, PR status, and Her2 status were significantly associated with the group who had a second tumor. Among the group with additional tumors found on MRI, histology, ER/PR status and grade were strongly correlated between the primary and the secondary lesion. Conclusions: Tumors that were larger, node positive, lobular histology, hormone receptor positive, or HER2-negative had a higher chance of having a second tumor on preoperative MRI. [Table: see text]