Imaging Appearance and Clinical Impact of Preoperative Breast MRI in Pregnancy-Associated Breast Cancer

Abstract

OBJECTIVE: The purpose of this study is to describe the imaging features of pregnancy-associated breast cancer (PABC) on breast MRI and to consider the impact of preoperative MRI on patient management. MATERIALS AND METHODS: A retrospective review of medical records from January 1994 to May 2014 identified 183 women who presented with a new diagnosis of breast cancer during pregnancy or within 1 year postpartum. MR images were available for 53 of these patients, all of whom were included in the study. Clinical history and available breast images were reviewed. The clinical impact of preoperative breast MRI was also recorded. RESULTS: Of the 53 women, nine (17%) presented during pregnancy and 44 (83%) presented during the first year postpartum. The sensitivity of MRI was 98% (52/53). Among the 53 patients, the most common findings of PABC on MRI included a solitary mass (29 patients [55%]), nonmass enhancement (12 patients [23%]), and multiple masses (eight patients [15%]). For 12 patients (23%), MRI showed a pathologically proven larger tumor size or greater extent of disease than did mammography or ultrasound, with an additional eight patients (15%) having findings suspicious for greater extent of disease but having unavailable pathologic data. Breast MRI changed surgical management for 15 patients (28%), with four patients (8%) requiring a larger lumpectomy, seven (13%) no longer being considered candidates for lumpectomy, two (4%) having contralateral disease, and two (4%) having unsuspected metastasis. CONCLUSION: Breast MRI had a high sensitivity for PABC in our study population. MRI may play an important role in PABC because it changed the surgical management of 28% of patients.