PURPOSE To evaluate imaging characteristics, outcome of surgical excision or imaging follow-up on high-risk lesions diagnosed at MRI-guided vacuum-assisted breast biopsy (MRI-VAB). MATERIALS AND METHODS We retrospectively reviewed 581 lesions, to include benign, high-risk and malignant lesions, undergoing 9-gauge MRI-VAB from January 2015 to April 2018. We collected patient demographics, risk factors and indications, breast MRI BI-RADS descriptors, histopathological diagnosis at MRI-VAB and surgical excision, frequency of upgrade to malignancy and imaging follow-up of high-risk lesions found in this period. RESULTS 101 patients with 107/581 (18.4% of all lesions) had high risk lesions at MRI-VAB, including atypical ductal hyperplasia (ADH)(n=19/107, 17.8%), lobular neoplasia (n=35/107, 32.7) including atypical lobular hyperplasia (ALH), lobular carcinoma in situ (LCIS), ALH plus LCIS, papillary lesions (n=44/107, 41.1%), radial scar/complex sclerosing lesion (RS/CSL)(n=8/107, 7.5%) and flat epithelial atypia (FEA)(n=1/107, 1%). 71/107 (66.4%) high risk lesions were excised. 16/71 (22.5%) were upgraded to malignancy (4 invasive cancer, 12 DCIS). The upgrade rate for ADH and lobular neoplasia was 5 /16 (31.3%) and 8/26 (30.8%) respectively. The upgrade rate for RS/CSL was 1/6 (16.7%). Of the 22 papillary lesions excised, 2 (9.1%) demonstrated pathologic atypia and were upgraded to DCIS. The other 20 papillary lesions had no upgrade or atypia. Excised high risk lesions showing upgrade varied from 0.4 to 6 cm in length (average 2.1 cm). Increasing size correlated with tendency towards increased upgrade to malignancy, but there were no other specific imaging features to predict malignancy upgrade. CONCLUSION There were no specific MRI imaging characteristics of high-risk lesions to predict malignancy upgrade. Therefore, surgical excision is recommended for high risk lesions especially ADH or lobular neoplasia. Additionally, non-atypical papillomas did not demonstrate malignancy upgrade in our small study. And further larger studies may demonstrate that these lesions may not need to be surgically excised. Citation Format: Okamoto S, Covelli JD, DeMartini WB, Daniel BL, Ikeda DM. High-risk lesions diagnosed at MRI-guided vacuum-assisted breast biopsy: Imaging characteristics, outcome of surgical excision or imaging follow-up [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-02-06.

Background: Magnetic resonance imaging (MRI) is a valuable tool for assessing extent of breast cancer and monitoring treatment response. Quantitative measures by diffusion-weighted MRI (DWI) and dynamic contrast-enhanced (DCE) MRI reflect tumor cellularity and vascularity. Tumor grade and some histopathological markers, such as ER, PR, HER-2, Ki67 and P53, are prognostic factors that can also be associated with tumor cellularity and vascularity. DWI and DCE measures may therefore provide a noninvasive means for predicting disease prognosis and stratifying patients to appropriate therapies. The purpose of this study was to investigate the correlation between quantitative MRI features and prognostic pathological factors in patients with invasive breast cancer. Methods: This IRB-approved retrospective study included patients with biopsy-proven invasive cancer who underwent 1.5T breast MRI (including DCE and DWI) from October 2005 to May 2006 prior to treatment. Pathology data was obtained from pre-treatment biopsy and intrinsic subtype classification was approximated by standard immunohistochemistry characteristics. After excluding cases with missing MRI or pathology data, the final study cohort included 41 invasive cancers (36 ductal and 5 lobular carcinomas) in 36 patients. MRI measures included lesion DCE kinetic features: peak initial enhancement (PE), percent rapid enhancement (RE), and percent washout (WO), and DWI normalized apparent diffusion coefficient values (nADC). Associations between imaging features and pathology markers, cancer grades and intrinsic subtypes were evaluated by Mann-Whitney U test and multivariate logistic regression. Results: Results of univariate comparisons are summarized in Table 1. One or more DCE-MRI kinetic parameters were significantly predictive (p<0.05) of each of the histopathological markers with the exception of ER, which was marginally associated with WO (p=0.05). Each of the DCE kinetics parameters significantly discriminated grade III tumors from grades I and II and luminal A from luminal B and basal-like intrinsic subtypes. In multivariate regression, both PE and WO were significant independent predictors of tumor grade (p=0.0094, p=0.0005, respectively). WO and nADC were significant independent predictors of PR status (p=0.0054, p=0.0027), while PE was the only significant independent predictor of both Ki67 (p=0.014) and intrinsic subtype (p=0.015). Conclusion: This preliminary study suggests that quantitative MRI measures are associated with prognostic tumor markers and may provide valuable noninvasive characterization of tumor biology. Larger prospective studies are needed to validate our findings. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-08-03.

This abstract was withdrawn by the authors. Citation Format: Wong MJ, Patel R, DeMartini WB, Todderud JE, Okamoto S, Ikeda DM. Withdrawn [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD4-02.

This abstract was withdrawn by the authors.