<abstract xmlns="http://www.w3.org/1999/xhtml"><sec id="j_raon-2019-0023_s_005_w2aab3b7c10b1b6b1aab1c18b1Aa"><h3>Background</h3><p>We analyzed the accuracy of magnetic resonance imaging (MRI) after primary systemic therapy (PST) according to tumor subtype.</p></sec><sec id="j_raon-2019-0023_s_006_w2aab3b7c10b1b6b1aab1c18b2Aa"><h3>Patients and methods</h3><p>Two-hundred and four breast cancer patients treated with PST were studied. MRI findings after PST were compared with pathologic findings, and results were stratified based on tumor subtype.</p></sec><sec id="j_raon-2019-0023_s_007_w2aab3b7c10b1b6b1aab1c18b3Aa"><h3>Results</h3><p>Of the two-hundred and four breast cancer patients, eighty-four (41.2%) achieved a pathologic complete response (pCR) in the breast. The MRI accuracy for predicting pCR was highest in triple-negative (TN) and HER2-positive (non-luminal) breast cancer (83.9 and 80.9%, respectively). The mean size discrepancy between MRI-measured and pathologic residual tumor size was lowest in TN breast cancer and highest in luminal B-like (HER2-negative) breast cancer (0.45cm <italic>vs</italic>. 0.98 cm, respectively; p = 0.003). After breast conserving surgery (BCS), we found a lower rate of positive margins in TN breast cancer and a higher rate of positive margins in luminal B-like (HER2-negative) breast cancer (2.4% <italic>vs</italic>. 23.6%, respectively).</p></sec><sec id="j_raon-2019-0023_s_008_w2aab3b7c10b1b6b1aab1c18b4Aa"><h3>Conclusions</h3><p>If tumor response after PST is assessed by MRI, tumor subtype should be considered when BCS is planned. The accuracy of MRI is highest in TN breast cancer.</p></sec></abstract>

BackgroundWe analyzed the accuracy of magnetic resonance imaging (MRI) after primary systemic therapy (PST) according to tumor subtype.Patients and methodsTwo-hundred and four breast cancer patients treated with PST were studied. MRI findings after PST were compared with pathologic findings, and results were stratified based on tumor subtype.ResultsOf the two-hundred and four breast cancer patients, eighty-four (41.2%) achieved a pathologic complete response (pCR) in the breast. The MRI accuracy for predicting pCR was highest in triple-negative (TN) and HER2-positive (non-luminal) breast cancer (83.9 and 80.9%, respectively). The mean size discrepancy between MRI-measured and pathologic residual tumor size was lowest in TN breast cancer and highest in luminal B-like (HER2-negative) breast cancer (0.45cm vs. 0.98 cm, respectively; p = 0.003). After breast conserving surgery (BCS), we found a lower rate of positive margins in TN breast cancer and a higher rate of positive margins in luminal B-like (HER2-negative) breast cancer (2.4% vs. 23.6%, respectively).ConclusionsIf tumor response after PST is assessed by MRI, tumor subtype should be considered when BCS is planned. The accuracy of MRI is highest in TN breast cancer.

Evaluation of MRI accuracy after primary systemic therapy in breast cancer patients considering tumor biology: optimizing the surgical planning

Radiology and Oncology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

BackgroundWe analyzed the accuracy of magnetic resonance imaging (MRI) after primary systemic therapy (PST) according to tumor subtype.Patients and...

Evaluation of MRI accuracy after primary systemic therapy in breast cancer patients considering tumor biology: optimizing the surgical planning

Article Category: Research Article

Published Online: May 08, 2019

Page range: 171 - 177

Received: Dec 25, 2018

Accepted: Apr 18, 2019

DOI: https://doi.org/10.2478/raon-2019-0023

© 2019 Alberto Bouzón, Ángela Iglesias, Benigno Acea, Cristina Mosquera, Paz Santiago, Joaquín Mosquera, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.