The Impact of Preoperative Breast MRI on Surgical Margin Status in Breast Cancer Patients Recalled at Biennial Screening Mammography: An Observational Cohort Study

Abstract

Background This study aimed to examine the association between preoperative magnetic resonance imaging (MRI) and surgical margin involvement, as well as to determine the factors associated with positive resection margins in screen-detected breast cancer patients undergoing breast-conserving surgery (BCS). Methods Breast cancer patients eligible for BCS and diagnosed after biennial screening mammography in the south of The Netherlands (2008–2017) were retrospectively included. Missing values were imputed and multivariable regression analyses were performed to analyze whether preoperative MRI was related to margin involvement after BCS, as well as to examine what factors were associated with positive resection margins, defined as more than focally (>4 mm) involved. Results Overall, 2483 patients with invasive breast cancer were enrolled, of whom 123 (5.0%) had more than focally involved resection margins. In multivariable regression analyses, preoperative MRI was associated with a reduced risk of positive resection margins after BCS (adjusted odds ratio [OR] 0.56, 95% confidence interval [CI] 0.33–0.96). Lobular histology (adjusted OR 2.86, 95% CI 1.68–4.87), large tumor size (per millimeter increase, adjusted OR 1.05, 95% CI 1.03–1.07), high (>75%) mammographic density (adjusted OR 3.61, 95% CI 1.07–12.12), and the presence of microcalcifications (adjusted OR 4.45, 95% CI 2.69–7.37) and architectural distortions (adjusted OR 1.85, 95% CI 1.01–3.40) were independently associated with positive resection margins after BCS. Conclusions Preoperative MRI was associated with lower risk of positive resection margins in patients with invasive breast cancer eligible for BCS using multivariable analysis. Furthermore, specific mammographic characteristics and tumor characteristics were independently associated with positive resection margins after BCS.

Updates and Debate Concerning Margin Adequacy and Management following Breast-Conserving Surgery

“…To reduce the reintervention rate after BCS, it is imperative to better determine the type of intervention preoperatively, as well as to adopt some intraoperative shrewdness [99,100]. For better planning of breast surgery, magnetic resonance imaging (MRI) has been widely applied with encouraging results, by lowering the re-excision rate after BCS [101] and by prompting an appropriate upgrade to mastectomy in a considerable number of cases, when warranted for cancer extent [102,103]. In patients affected by triple-negative breast cancer, MRI improved the local recurrence rate after BCS [104].…”

ASO Author Reflections: Impact of Preoperative MRI on Patients With Screen-Detected Invasive Breast Cancer Undergoing Breast-Conserving Surgery

“…Using multivariable analysis, this study found that selective use of preoperative MRI was associated with a lower risk of positive resection margins (involved margins [ 4 mm) after BCS for patients with screen-detected invasive breast cancer (adjusted odds ratio [OR], 0.56; 95% confidence interval [CI], 0.33-0.96). 4 Moreover, the presence of microcalcifications (adjusted OR, 4.45; 95% CI, 2.69-7.37), architectural distortions (adjusted OR, 1.85; 95% CI, 1.01-3.40), high ([ 75 %) mammographic breast density (adjusted OR, 3.61; 95% CI, 1.07-12.12), lobular histology (adjusted OR, 2.86; 95% CI, 1.68-4.87), and increasing tumor size (per mm of increase; adjusted OR, 1.05; 95% CI, 1.03-1.07) were independently associated with positive resection margins after BCS. Because most of these factors can be assessed preoperatively, they may improve surgical planning and thereby margin status after BCS.…”

Magnetic resonance imaging of the breast– where are we in 2021?

“…Based on current evidence, there is a clear benefit of routine preoperative breast MRI (15,16), resulting in fewer tumors with positive resection margins and decreased number of reoperations. Commonly stated downsides of this approach are: examination cost, need for intravenous contrast administration, and prolonged median of waiting for surgery somewhere from 22-39 days, which has a negative psychological effect on the patient.…”