BRIEF REPORT Relationship of breast MRI to recurrence rates in patients undergoing breast-conservation treatment Maureen V. Hill 1 • Julia L. Beeman 1 • Khushboo Jhala 2 • Stefan D. Holubar 1 • Kari M. Rosenkranz 1 • Richard J. Barth Jr. 1 Received: 11 March 2017 / Accepted: 14 March 2017 Ó Springer Science+Business Media New York 2017 Abstract Purpose The effect of pre-operative MRI on the in-breast tumor recurrence rate (IBTR) of patients undergoing breast-conservation treatment (BCT) remains uncertain. We began to routinely perform pre-operative MRI in 2006. Our goal was to determine the effect of pre-operative MRI on IBTR. Methods Retrospective review of a prospective database of all patients undergoing BCT (n = 1396) from 2000 to 2010. IBTR were calculated using Kaplan–Meier estimates. Results 664 (47.6%) patients underwent pre-operative MRI. The use of MRI increased from 13.9% in 2000–2005 to 80.7% in 2006–2010. Ten percent of patients who underwent MRI were found to have an additional ipsilat- eral cancer, with a mean diameter of 1.6 cm. The IBTR for patients with and without MRI were 4% vs. 8% at 8 years (p = 0.04). In multivariate analysis, radiation therapy and endocrine therapy were associated with decreased IBTR, but MRI was not (RR 0.77 (0.45–1.28)). For 1030 patients with invasive cancer, the IBTR at 8 years with and without MRI was 4.2% vs. 7.3% (p = 0.28). For 366 DCIS patients with and without MRI, the IBTR was 3.6% vs. 10.9% (p = 0.06). In the subgroup of DCIS patients who did not receive radiation, the IBTR with and without MRI was 0% vs. 18.2% (p = 0.08). Patients with an additional cancer found by MRI had a higher IBTR at 8 years (10.1% vs. 3.3%, p = 0.02). Conclusions In a study analyzing BCT patients from one time period who rarely had a pre-operative MRI and a subsequent time period where most patients had MRI, the use of MRI was associated with a decrease in the IBTR on univariate, but not multivariate analysis. Patients who had additional cancers detected had a significantly higher IBTR. Keywords Breast MRI Á Breast cancer recurrence Á In-breast tumor recurrence Introduction The role of pre-operative magnetic resonance imaging (MRI) in patients with newly diagnosed breast cancer remains controversial. One rationale for its use is to enable surgeons to identify additional sites of cancer in the ipsi- lateral breast. It has been well established by meta-analyses involving thousands of patients that the superior sensitivity of MRI enables additional lesions to be found in 16–20% of patients [1, 2]. These studies have also shown that approximately 2/3 of these lesions will be malignant: resulting in the detection of additional ipsilateral malig- nancies in 11–14% of patients. An unresolved key question is whether these MRI-de- tected cancers need to be excised, or whether adjuvant therapies will be sufficient to prevent their growth. If these additional MRI-detected cancers were all small, one could plausibly hypothesize that adjuvant therapy might be suf- ficient. However, several studies evaluating the size of additional MRI-detected cancers have found that the median tumor diameter ranges from 10 to 15 mm [3–5]. Surgical excision, not radiation and/or hormonal treatment, is standard therapy for cancers of this size. & Richard J. Barth Jr. Richard.J.Barth.Jr@hitchcock.org 1 Section of General Surgery, Dartmouth Hitchcock Medical Center, 1 Medical Center Drive, Lebanon, NH 03756, USA 2 Geisel School of Medicine at Dartmouth, Hanover, NH, USA 123 Breast Cancer Res Treat DOI 10.1007/s10549-017-4205-9