Breast Magnetic Resonance Imaging Can Predict Ki67 Discordance Between Core Needle Biopsy and Surgical Samples

Abstract

Background: Disagreement in assessments of Ki67 expression based on core-needle biopsy and matched surgical samples complicates decisions in the treatment of breast cancer. Purpose: To examine whether preoperative breast MRI could be useful in predicting Ki67 discordance between core-needle biopsy and surgical samples. Study Type: Retrospective. Population: Three hundred and sixty-five breast cancer patients with MRI scans and having both core-needle biopsy and surgical samples from 2017 to 2019. Field Strength/Sequence: 3.0 T, T2-weighted iterative decomposition of water and fat with echo asymmetry and least squares estimation sequence, diffusion-weighted sequence using b-values 0/1000, dynamic contrast enhanced image by volume imaged breast assessme NT. Assessment: We collected clinicopathologic variables and preoperative MRI features (tumor size, lesion type, shape of mass, spiculated margin, internal enhancement, peri-tumoral edema, intra-tumoral necrosis, multifocal/multicentric, apparent diffusion coefficient [ADC] minimum, ADC mean, ADC maximum, ADC difference). Statistical Tests: K-means clustering, multivariable logistic regression, receiver operating characteristic curve. Results: Sixty-one patients showed Ki67 discordance and 304 patients show Ki67 concordance according to our definition using K-means clustering. Multivariable regression analysis showed that the following parameters were independently associated with Ki67 discordance: peri-tumoral edema, odds ratio (OR) 2.662, 95% confidence interval (CI) 1.432-4.948; ADCmin ≤ 0.829 Â 10 À3 mm 2 /sec, OR 2.180, 95% CI 1.075-4.418; and ADCdiff > 0.317 Â 10 À3 mm 2 /sec, OR 3.365, 95% CI 1.698-6.669. This multivariable model resulted in an AUC of 0.758 (95% CI 0.711-0.802) with sensitivity and specificity being 0.803 and 0.621, respectively. Conclusion: Presence of peri-tumoral edema, smaller ADCmin and greater ADCdiff in preoperative breast MRI may indicate high risk of Ki67 discordance between core-needle biopsy and surgical samples. For patients with these MRI-based risk factors, clinicians should not rely on Ki67 assessment only from core-needle biopsy.

Editorial for “Breast Magnetic Resonance Imaging Can Detect Ki67 Discordance Between Core Needle Biopsy and Surgical Samples”

“…5 In this issue of JMRI, the article "Breast magnetic resonance imaging can detect Ki67 discordance between coreneedle biopsy and surgical samples" used conventional MRI features and ADC parameters to investigate whether preoperative breast MRI could be useful in predicting Ki67 discordance between core-needle biopsy and surgical samples. 6 The included MRI features are those easily assessable in clinical practice, and ADC parameters were determined by drawing multiple 5 mm diameter ROIs on a representative slice to encompass the entire cross-section of the lesion. Of note, the authors did not define Ki67 discordance based on the 20% threshold but used K-means clustering analysis.…”