Min Sun Bae MD, PhD, Presenter: Nothing to Disclose

Woo Kyung Moon, Abstract Co-Author: Nothing to Disclose

Nariya Cho MD, Abstract Co-Author: Nothing to Disclose

Su Hyun Lee MD, Abstract Co-Author: Nothing to Disclose

Won Hwa Kim MD, PhD, Abstract Co-Author: Nothing to Disclose

Sung Eun Song MD, Abstract Co-Author: Nothing to Disclose

A Jung Chu MD, Abstract Co-Author: Nothing to Disclose

Sung Ui Shin MD, Abstract Co-Author: Nothing to Disclose

To determine whether preoperative MRI findings differ according to breast cancer subtype and to examine the relationship between the pattern of recurrence and breast cancer subtype in women treated with breast conserving therapy (BCT).

A total of 102 primary breast cancer patients (mean age, 45 years; range, 22-78 years) treated with BCT who had preoperative breast MRI and locoregional recurrence after BCT between September 2003 and December 2012 were included in the study. Patients who underwent neoadjuvant chemotherapy or surgical excision prior to MRI were excluded. Two breast imaging radiologists blinded to the clinicopathologic data assessed fibroglandular tissue (FGT) and background parenchymal enhancement (BPE) on MRI using BI-RADS criteria. Presence of multifocal/multicentric disease and lymph node involvement were evaluated. The pattern of recurrence and detection method were examined. Breast cancer subtypes were defined as luminal (ER+ and PR+), HER2+ (ER-, PR-, and HER2+), and triple-negative (TN; ER-, PR-, and HER2-). MRI and clinical features were compared between the breast cancer subtypes.

The 102 cases were classified as 56 (55%) luminal, 17 (17%) HER2+, and 29 (28%) TN subtype. Women with dense breasts were more likely to have luminal subtype compared to HER2+ or TN subtypes (95% vs (71%, 79%), p = 0.013). Multifocal/multicentric disease was more frequently detected by MRI in HER2+ subtype, compared to luminal or TN subtypes (59% vs (20%, 21%), p = 0.002). Ipsilateral breast cancer recurrence was more frequently observed in HER2+ subtype, compared to luminal or TN subtypes (88% vs (50%, 62%), p = 0.018). Compared to luminal subtype, HER2+ and TN subtypes were more likely to be associated with clinically detected recurrence (11% vs (41%, 41%), p = 0.002). There were no significant differences in BPE and lymph node involvement between subtypes.

Preoperative breast MRI is more likely to detect multifocal/multicentric disease in HER2+ breast cancer and FGT on MRI is more likely to be associated with luminal breast cancer. Patients with HER2+ and TN breast cancers more frequently have clinically detected recurrence.

The use of preoperative breast MRI and the postoperative imaging follow-up strategy could be tailored according to breast cancer subtype in women treated with BCT.

Bae, M, Moon, W, Cho, N, Lee, S, Kim, W, Song, S, Chu, A, Shin, S, Preoperative MRI Features and Patterns of Recurrence according to Breast Cancer Subtype in Women Treated with Breast Conserving Therapy .  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14017769.html