The Impact of Preoperative Breast Magnetic Resonance Imaging on Surgical Management in Symptomatic Patients With Invasive Lobular Carcinoma

Brian M Moloney; Peter F McAnena; Éanna J Ryan; Ellen O Beirn; Ronan M Waldron; AnnaMarie O Connell; Sinead Walsh; Rachel Ennis; Catherine Glynn; Aoife J Lowery; Peter A McCarthy; Michael J Kerin

doi:10.1177/1178223420948477

The Impact of Preoperative Breast Magnetic Resonance Imaging on Surgical Management in Symptomatic Patients With Invasive Lobular Carcinoma

Breast Cancer (Auckl). 2020 Aug 14:14:1178223420948477. doi: 10.1177/1178223420948477. eCollection 2020.

Authors

Brian M Moloney^{1

2}, Peter F McAnena^{2

3}, Éanna J Ryan³, Ellen O Beirn³, Ronan M Waldron^{2

3}, AnnaMarie O Connell¹, Sinead Walsh¹, Rachel Ennis¹, Catherine Glynn¹, Aoife J Lowery^{2

3}, Peter A McCarthy¹, Michael J Kerin^{2

3}

Affiliations

¹ Department of Radiology, Galway University Hospital, Saolta University Health Care Group, Galway, Ireland.
² Discipline of Surgery, Lambe Institute for Translational Research, School of Medicine, National University of Ireland Galway, Galway, Ireland.
³ Department of Surgery, Galway University Hospital, Saolta University Health Care Group, Galway, Ireland.

Abstract

Objective: Due to an insidious proliferative pattern, invasive lobular breast cancer (ILC) often fails to form a defined radiological or palpable lesion and accurate diagnosis remains challenging. This study aimed to determine the value of preoperative magnetic resonance imaging (MRI) for ILC and its impact on surgical outcomes.

Methods: Consecutive symptomatic patients diagnosed with ILC in a tertiary centre over a 9-year period were reviewed. The time from diagnosis until surgery, initial type of surgery/index operation (breast-conserving surgery [BCS]/mastectomy) and the rates of reoperation (re-excision/completion mastectomy) were recorded. Patients were grouped into those who received conventional imaging and preoperative MRI (MR+) and those who received conventional imaging alone (MR-).

Results: There were 218 cases of ILC, and 32.1% (n = 70) had preoperative MRI. Time from diagnosis to surgery was longer in the MR+ than the MR- group (32.5 vs 21.1 days, P < .001) even when adjusting for age and breast density. Initial BCS was performed on 71.4% (n = 50) of MR+ patients and 72.3% (n = 107) of the MR- group. While the rate of completion mastectomy following initial BCS was higher in the MR+ group (30.0%, n = 15 vs 14.0%, n = 15; χ² = 5.63; P = .018), this association was not maintained in multivariable analysis. No difference was recorded in overall (initial and completion) mastectomy rate between the MR+ and MR- group (50.0%, n = 35 vs 37.8%, n = 56; χ² = 2.89; P = .089). Margin re-excision following BCS was comparable between groups (8.0%, n =4, vs 9.3%, n = 10; χ² = 0.076, P = .783) despite the selection bias for borderline conservable cases in the MR+ group. The rate of usage of MRI for ILC cases declined over the study period.

Conclusion: While MRI was associated with minor delays in treatment and did not reduce overall rates of margin re-excision or completion mastectomy, it altered the choice of surgical procedure in almost a quarter of MR+ cases. The benefit of preoperative breast MRI appears to be confined to select (younger, dense breast, borderline conservable) cases in symptomatic ILC.

Keywords: Breast cancer; ILC; MRI; invasive lobular cancer; surgical outcomes.