Comparing the performance of full-field digital mammography and digital breast tomosynthesis in the post-treatment surveillance of patients with a history of breast cancer: A retrospective study

INTRODUCTION

The purpose of our study was to compare the performance of 2D (FFDM) against 3D (FFDM plus DBT) examinations in the post-treatment surveillance of asymptomatic breast cancer survivors.

METHODS

A list of women with a history of breast cancer who underwent screening mammography (2D or 3D) from 5/2017 to 5/2020 was retrieved. A total of 20,210 examinations were identified and performance metrics were compared.

RESULTS

There were no statistically significant difference in cancer detection rate (CDR) (p = 0.38), recall rate (RR) (p = 0.087), or positive predictive value (PPV) (p = 0.74) between 2D vs. 3D examinations. Stratification by breast tissue identified no statistically significant difference in CDR (p = 0.581 and p = 0.428), RR (p = 0.230 and p = 0.205), or PPV (p = 0.908 and p = 0.721) between fatty/scattered and heterogeneous/extremely dense breast tissue when comparing 2D vs 3D examinations. Stratification by age did not identify a significant difference in RR or PPV between the two groups. CDR was statistically increased with 2D vs. 3D examinations in the 60-69 years group (p = 0.021). Stratification by race did not identify a significant difference in RR or PPV between the two groups. CDR was statistically increased with 3D vs. 2D examinations in white women (p = 0.036). Stratification by laterality (bilateral vs. unilateral post mastectomy) did not identify a significant difference in RR or PPV between the two groups. CDR was statistically increased in 2D vs. 3D examinations in unilateral studies (p = 0.009).

CONCLUSION

For asymptomatic women with a history of breast cancer, there is no evidence that the addition of DBT to FFDM improves CDR, RR, or PPV.

IMPLICATIONS FOR PRACTICE

More studies are needed concerning screening methodologies supplementing FFDM in the screening regimens of breast cancer survivors.

PTEN in triple-negative breast carcinoma: protein expression and genomic alteration in pretreatment and posttreatment specimens

Background

Recent advances have been made in targeting the phosphoinositide 3-kinase pathway in breast cancer. Phosphatase and tensin homolog (PTEN) is a key component of that pathway.

Objective

To understand the changes in PTEN expression over the course of the disease in patients with triple-negative breast cancer (TNBC) and whether PTEN copy number variation (CNV) by next-generation sequencing (NGS) can serve as an alternative to immunohistochemistry (IHC) to identify PTEN loss.

Methods

We compared PTEN expression by IHC between pretreatment tumors and residual tumors in the breast and lymph nodes after neoadjuvant chemotherapy in 96 patients enrolled in a TNBC clinical trial. A correlative analysis between PTEN protein expression and PTEN CNV by NGS was also performed.

Results

With a stringent cutoff for PTEN IHC scoring, PTEN expression was discordant between pretreatment and posttreatment primary tumors in 5% of patients (n = 96) and between posttreatment primary tumors and lymph node metastases in 9% (n = 33). A less stringent cutoff yielded similar discordance rates. Intratumoral heterogeneity for PTEN loss was observed in 7% of the patients. Among pretreatment tumors, PTEN copy numbers by whole exome sequencing (n = 72) were significantly higher in the PTEN-positive tumors by IHC compared with the IHC PTEN-loss tumors (p < 0.0001). However, PTEN-positive and PTEN-loss tumors by IHC overlapped in copy numbers: 14 of 60 PTEN-positive samples showed decreased copy numbers in the range of those of the PTEN-loss tumors.

Conclusion

Testing various specimens by IHC may generate different PTEN results in a small proportion of patients with TNBC; therefore, the decision of testing one versus multiple specimens in a clinical trial should be defined in the patient inclusion criteria. Although a distinct cutoff by which CNV differentiated PTEN-positive tumors from those with PTEN loss was not identified, higher copy number of PTEN may confer positive PTEN, whereas lower copy number of PTEN would necessitate additional testing by IHC to assess PTEN loss.

Trial registration

NCT02276443.

Predictive Roles of Baseline Stromal Tumor-Infiltrating Lymphocytes and Ki-67 in Pathologic Complete Response in an Early-Stage Triple-Negative Breast Cancer Prospective Trial

High stromal tumor-infiltrating lymphocytes (sTILs) are associated with improved pathologic complete response (pCR) in triple-negative breast cancer (TNBC). We hypothesize that integrating high sTILs and additional clinicopathologic features associated with pCR could enhance our ability to predict the group of patients on whom treatment de-escalation strategies could be tested. In this prospective early-stage TNBC neoadjuvant chemotherapy study, pretreatment biopsies from 408 patients were evaluated for their clinical and demographic features, as well as biomarkers including sTILs, Ki-67, PD-L1 and androgen receptor. Multivariate logistic regression models were developed to generate a computed response score to predict pCR. The pCR rate for the entire cohort was 41%. Recursive partitioning analysis identified ≥20% as the optimal cutoff for sTILs to denote 35% (143/408) of patients as having high sTILs, with a pCR rate of 59%, and 65% (265/408) of patients as having low sTILs, with a pCR rate of 31%. High Ki-67 (cutoff > 35%) was identified as the only predictor of pCR in addition to sTILs in the training set. This finding was verified in the testing set, where the highest computed response score encompassing both high sTILa and high Ki-67 predicted a pCR rate of 65%. Integrating Ki67 and sTIL may refine the selection of early stage TNBC patients for neoadjuvant clinical trials evaluating de-escalation strategies.

Abstract P6-01-06: Multi-Parametric MRI-Based Radiomics Models from Tumor and Peritumoral Regions as Potential Predictors of Treatment Response to Neoadjuvant Systemic Therapy in Triple Negative Breast Cancer Patients

PURPOSE Triple negative breast cancer (TNBC) is an aggressive and heterogeneous subtype of breast cancer. Pathologic complete response (pCR) to neoadjuvant systemic therapy (NAST) predicts better survival. Early prediction of the treatment response can potentially triage non-responding patients to alternative protocol treatments, spare them of the unneeded toxicity, and improve pCR. We evaluated the ability of radiomic textural analysis of intratumoral and peritumoral regions on the dynamic contrast enhanced (DCE) and diffusion-weighted imaging (DWI) MRI images obtained early during NAST to predict pCR. MATERIALS AND METHODS This IRB-approved prospective study (NCT02276443) included 182 patients with biopsy proven stage I-III TNBC who had multiparametric MRIs at baseline (BL), post 2 cycles (C2), and post 4 cycles (C4) of NAST before surgery. Tumors and peritumoral regions of 5 mm and 10 mm in thickness were segmented on the 2.5 minutes DCE subtraction images and on the b=800 DWI images. Ten histogram-based first order texture features including mean, minimum, maximum, standard deviation, kurtosis, skewness, 1st, 5th, 95th, and 99th percentile, and 300 radiomic Grey Level Co-occurrence matrix (GLCM) features along with their absolute and relative differences between the 3 imaging time points were extracted from the tumors and from the peritumoral regions with an in-house Matlab toolbox. Treatment response at surgery (pCR vs non-pCR) was documented. The samples were divided into training and testing datasets by a 2:1 ratio. Area under the receiver operating characteristics curve (AUC ROC) was calculated for univariate analysis in predicting pCR. Logistic regression with elastic net regularization was performed for texture feature selection. Parameter optimization was performed by using 5-fold cross-validation based on mean cross-validated AUC in the training set. RESULTS Of 182 TNBC patients, 88 (48%) had pCR and 94 (52%) did not achieve pCR. Eight multivariate models combining radiomic features from both DCE and DWI tumoral and peritumoral regions had AUC &gt; 0.8 (0.807-0.831) with p-value &lt; 0.001 in both training and testing sets. The highest AUC=0.831 was obtained from a model consisting of 15 radiomic features: tumor DWI (5 GLCM features) at C2, peritumoral region on DCE (skewness) at C2, tumor DCE (1st, 5th percentile) at C4, tumor DWI (3 GLCM features) at C4, peritumoral region DWI (1 GLCM feature) at C4, and the relative difference between C4/C2 on DCE (5th, 95th percentile and mean). CONCLUSION Multi-parametric MRI-based radiomics models from the tumor and the peritumoral regions showed high accuracy as potential early predictors of NAST response in TNBC patients.

Citation Format: Rania M. Mohamed, Bikash Panthi, Beatriz Adrada, Rosalind Candelaria, Mary S. Guirguis, Wei Yang, Medine Boge, Miral Patel, Nabil Elshafeey, Sanaz Pashapoor, Zijian Zhou, Jong Bum Son, Ken-Pin Hwang, H. T. Carisa Le-Petross, Jessica Leung, Marion E. Scoggins, Gary J. Whitman, Zhan Xu, Deanna L. Lane, Tanya Moseley, Frances Perez, Jason White, Elizabeth Ravenberg, Alyson Clayborn, Mark Pagel, Huiqin Chen, Jia Sun, Peng Wei, Alastair M. Thompson, Stacy Moulder, Anil Korkut, Lei Huo, Kelly K. Hunt, Jennifer K. Litton, Vicente Valero, Debu Tripathy, Clinton Yam, Jingfei Ma, Gaiane Rauch. Multi-Parametric MRI-Based Radiomics Models from Tumor and Peritumoral Regions as Potential Predictors of Treatment Response to Neoadjuvant Systemic Therapy in Triple Negative Breast Cancer Patients [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-01-06.

Abstract P6-01-34: Longitudinal DCE-MRI Radiomic Models for Early Prediction of Response to Neoadjuvant Systemic Therapy (NAST) in Triple Negative Breast Cancer (TNBC) Patients

Background and Purpose Early prediction of neoadjuvant systemic therapy (NAST) response in triple negative breast cancer (TNBC) patients could potentially aid in the selection of alternative therapies and avoid unnecessary toxicity in patients unlikely to achieve pathologic complete response (pCR) with NAST. In this study, we investigated the radiomic features of the peritumoral and the tumoral regions from dynamic contrast enhanced (DCE) MRI acquired at different time points of NAST for early treatment response prediction in TNBC. Methods and Materials This study included 182 biopsy-confirmed stage I-III TNBC patients enrolled in an IRB approved prospective clinical trial (NCT02276433). All patients underwent DCE-MRI on a GE 3T MRI scanner at baseline (BL), after two (C2) and four (C4) cycles of doxorubicin/cyclophosphamide based chemotherapy and before surgery. The peritumoral and the tumoral regions were segmented manually by two fellowship-trained radiologists using early phase (2.5 min) DCE-MRI subtraction images. Ten first order radiomic features, 300 grey-level-co-occurrence matrix (GLCM) features along with their absolute and relative differences (C4/BL, C2/BL, C4/C2) between the 3 imaging time points were extracted from the peritumoral and the tumoral regions. Patients were randomly divided into training and testing sets in a 2:1 ratio. For univariate analysis, area under the receiver operating characteristics curve (AUC ROC) was measured to determine the features most predictive of pCR/non-pCR. Wilcoxon Rank Sum test was used to test the statistical significance of predictive performance. In multivariate analysis, radiomic models were established using logistic regression with elastic net regularization followed by 5-fold cross validation for performance assessment. Results Eighty-eight (48%) patients had pCR (59 training, 29 testing) and 94 (52%) patients had non-pCR (63 training, 31 testing). Twenty-five radiomic features (4 from peritumoral C4, 5 from tumoral C4, 4 from peritumoral C4/BL, 6 from tumoral C4/BL, 2 from peritumoral C4/C2 and 4 from tumoral C4/C2) were statistically significant with AUC ≥ 0.75 in both the training and the testing sets at the univariate analysis. The significant features at C4 had AUCs of 0.75-0.79 for the training set and 0.76-0.81 for the testing set. Changes measured between C4 and BL or C2 showed AUC of 0.76-0.84 in the training and 0.75-0.81 in the testing datasets. Eleven multivariate regression models comprised of radiomic features at BL, C2, C4 and their changes (C4/BL, C4/C2 and C2/BL) showed an AUC of 0.80-0.84 for cross validation and an AUC of 0.80-0.82 for independent testing. Conclusions Radiomic models using longitudinal DCE MRI parameters of peritumoral and tumoral regions during NAST have the potential to predict pCR in TNBC patients undergoing NAST.

Citation Format: Bikash Panthi, Rania M. Mohamed, Beatriz Adrada, Rosalind Candelaria, Mary S. Guirguis, Wei Yang, Medine Boge, Miral Patel, Nabil Elshafeey, Sanaz Pashapoor, Zijian Zhou, Jong Bum Son, Ken-Pin Hwang, H. T. Carisa Le-Petross, Jessica Leung, Marion E. Scoggins, Gary J. Whitman, Zhan Xu, Deanna L. Lane, Tanya Moseley, Frances Perez, Jason White, Elizabeth Ravenberg, Alyson Clayborn, Mark Pagel, Huiqin Chen, Jia Sun, Peng Wei, Alastair M. Thompson, Stacy Moulder, Anil Korkut, Lei Huo, Kelly K. Hunt, Jennifer K. Litton, Vicente Valero, Debu Tripathy, Clinton Yam, Jingfei Ma, Gaiane Rauch. Longitudinal DCE-MRI Radiomic Models for Early Prediction of Response to Neoadjuvant Systemic Therapy (NAST) in Triple Negative Breast Cancer (TNBC) Patients [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-01-34.

Abstract HER2-01: HER2-01 Clinical and Molecular Characteristics of HER2-low/zero Early Stage Triple-Negative Breast Cancer

Background: In the metastatic setting, low HER2 expression is associated with clinical benefit from trastuzumab deruxtecan, a HER2-targeting antibody drug conjugates. However, little is known about the biological significance of low HER2 expression in patients with early stage triple-negative breast cancer (TNBC) receiving neoadjuvant therapy (NAT). Methods: Out of 595 patients with stage I-III TNBC enrolled on the prospective ARTEMIS trial (NCT02276443) from 2015-2021, we identified 367 patients with available HER2 immunohistochemistry (IHC) results on pre-NAT tumor tissue (HER2-zero: n=218; HER2-low [IHC 1+, 2+]: n=149). All patients were treated with anthracycline-based NAT. In cases where sufficient pre-NAT tumor tissue were available, additional IHC and/or RNAseq were performed. Differential gene expression (DGE) and pathway analysis were performed using DEseq2. Gene set enrichment analysis (GSEA) was performed using the Hallmark gene sets. Deconvolution analyses were performed using CIBERSORT. We controlled for multiple hypothesis using a false discovery rate (FDR) threshold with the Benjamini-Hochberg method, accepting as significant genes with at least a 2-fold change and &lt; 5% FDR. Results: Table 1 summarizes baseline clinicopathological features of the 367 patients. Compared to HER2-zero tumors, HER2-low tumors were less likely of metaplastic histology (p=0.001), associated with lower Ki67 (p=0.017) and were more likely to be androgen receptor (AR)-positive (p=0.01). There were no significant differences in tumor-infiltrating lymphocytes (TILs) infiltration and PD-L1 expression between HER2-zero and HER2-low tumors. Among the 226 patients with sufficient pre-NAT tissue for RNAseq, DGE analyses demonstrated upregulation of genes involved in fatty acid metabolism (ACSM1) and steroid hormone metabolism (DHRS2, UGT2B28) in HER2-low tumors compared with HER2-zero tumors. Deconvolution analyses revealed no significant differences between predicted proportions of immune cell subpopulations between HER2-low and HER2-zero tumors. Although rates of pCR were not significantly different between patients with HER2-zero (46%) and HER2-low tumors (40%) (p=0.34), non-pCR in patients with HER2-low tumors was associated with increased expression of EREG, which encodes an EGFR ligand, while non-pCR in patients with HER2-zero tumors was associated with downregulation in genes involved in immune response pathways. GSEA further identified the Hallmark allograft rejection (FDR q=0.001), interferon gamma response (FDR q=0.002), and interferon alpha response pathways (FDR q=0.007) as the 3 most significantly downregulated pathways in HER2-zero tumors from patients experiencing a non-pCR relative to HER2-zero tumors from patients experiencing a pCR. Conclusion: In early stage TNBC, low HER2 expression is associated with increased AR expression and upregulation of genes associated with fatty acid and steroid hormone metabolism. Gene expression analyses suggest that drivers of resistance to NAT differ between HER2-low and HER2-zero tumors. Biological differences between HER2-zero and HER2-low tumors exist and may influence future personalized treatment for patients with early stage TNBC.

Citation Format: Clinton Yam, Ziyi Li, Anil Korkut, Wencai Ma, Elisabeth Kong, Holly A. Hill, Hussein Abbas, Sausan Abouharb, Beatriz Adrada, Banu K. Arun, Carlos H. Barcenas, Ajit Bisen, Daniel Booser, Aman Buzdar, Rosalind Candelaria, Junjie Chen, Alyson Clayborn, Senthil Damodaran, Qingqing Ding, Haven Garber, Gabriel N. Hortobagyi, Kelly K. Hunt, Nuhad K. Ibrahim, Adaeze Iheme, Meghan S. Karuturi, Kimberly Koenig, Rachel M. Layman, Jangsoon Lee, Jennifer K. Litton, Melissa Mitchell, Giancarlo Moscol, Jason Mouabbi, Rashmi K. Murthy, Oluchi Oke, Paula Pohlmann, David Ramirez, Elizabeth Ravenberg, Sadia Saleem, Mediget Teshome, Vicente Valero, Jason White, Madison Williams, Wendy Woodward, Chasity Yajima, Naoto T. Ueno, Ken Chen, Gaiane Rauch, Lei Huo, Debu Tripathy. HER2-01 Clinical and Molecular Characteristics of HER2-low/zero Early Stage Triple-Negative Breast Cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr HER2-01.

Abstract P1-05-15: DCE-MRI for early prediction of excellent response versus chemoresistance in triple negative breast cancer

PURPOSE Triple-negative breast cancer (TNBC) is a heterogeneous disease with variable response to neoadjuvant therapy (NAT). Pathologic complete response (pCR) has become a prognostic marker for overall and disease-free survival. The aim of this study was to determine if dynamic contrast-enhanced (DCE)-MRI after 2 and/or 4 cycles of NAT can identify patients with a high likelihood of achieving pCR, triaging them to standard of care (SOC), or, when appropriate, to de-escalation trials. Conversely, we aimed to identify chemoresistant tumors that are unlikely to achieve pCR and may benefit from escalated targeted trials.

METHOD AND MATERIALS 309 patients with stage I-III TNBC underwent DCE-MRI (temporal resolution: 9-12 sec) at baseline (BL), 2 cycles (C2), and 4 cycles (C4) of SOC doxorubicin/cyclophosphamide (AC) NAT as part of a prospective IRB-approved study (NCT02276443). Tumor volumes of the index lesion were calculated using 3 axis measurements during the early phase of the DCE-MRI (60s). Percent tumor volume reduction (TVR) between BL, C2, and C4 was calculated. Patients were randomly assigned to a training or a validation cohort in a 1:1 ratio. pCR was assessed at surgery after completion of SOC NAT. Correlation between pCR and TVR was evaluated using ROC analysis.

RESULTS Of 309 TNBC patients, 136 (44%) achieved pCR. Following 2 cycles of NAT, TVR &gt;80% was predictive of pCR (chemosensitivity), while TVR ≤ 55% was predictive of non-pCR (chemoresistance) with PPV 80%, NPV 89%, AUC 0.811 (0.73~0.893, p&lt; 0.0001) in the training cohort, and PPV 82%, NPV 85%, AUC 0.815 (CI:0.736~0.894, p&lt; 0.0001) in the validation cohort. Following 4 cycles of NAT, TVR &gt;90% was predictive of pCR, while TVR ≤80% was predictive of non-pCR with PPV 80%, NPV 84%, AUC 0.827 (0.756~0.898, p&lt; 0.0001) in the training cohort and with PPV 73%, NPV 82%, AUC 0.785 (CI:0.709~0.862, p&lt; 0.001) in the validation cohort. Using this model, the pCR status was correctly classified in 50% of TNBC patients using C2 DCE-MRI in the training cohort, and 54% in the validation cohort. Only 8% were misclassified in the training cohort, and 10% in the validation cohort. Using C4 DCE-MRI, the pCR status of 61% and 57% of TNBC was correctly classified in the validation and the testing cohorts, respectively. 12% were misclassified in the validation cohort, and 21% in the testing cohort.

CONCLUSION DCE-MRI after 2 and 4 cycles of AC-based NAT correctly predicted the pCR status of 54% and 57% of TNBC patients, respectively, as either excellent responders or nonresponders with high AUC 0.811 and 0.827. This may allow patients to be triaged to SOC NAT with option of de-escalation or early targeted therapies for non-responders.

Predictors of success in establishing orthotopic patient-derived xenograft models of triple negative breast cancer

Patient-derived xenograft (PDX) models of breast cancer are an effective discovery platform and tool for preclinical pharmacologic testing and biomarker identification. We established orthotopic PDX models of triple negative breast cancer (TNBC) from the primary breast tumors of patients prior to and following neoadjuvant chemotherapy (NACT) while they were enrolled in the ARTEMIS trial (NCT02276443). Serial biopsies were obtained from patients prior to treatment (pre-NACT), from poorly responsive disease after four cycles of Adriamycin and cyclophosphamide (AC, mid-NACT), and in cases of AC-resistance, after a 3-month course of different experimental therapies and/or additional chemotherapy (post-NACT). Our study cohort includes a total of 269 fine needle aspirates (FNAs) from 217 women, generating a total of 62 PDX models (overall success-rate = 23%). Success of PDX engraftment was generally higher from those cancers that proved to be treatment-resistant, whether poorly responsive to AC as determined by ultrasound measurements mid-NACT (p = 0.063), RCB II/III status after NACT (p = 0.046), or metastatic relapse within 2 years of surgery (p = 0.008). TNBC molecular subtype determined from gene expression microarrays of pre-NACT tumors revealed no significant association with PDX engraftment rate (p = 0.877). Finally, we developed a statistical model predictive of PDX engraftment using percent Ki67 positive cells in the patient's diagnostic biopsy, positive lymph node status at diagnosis, and low volumetric reduction of the patient's tumor following AC treatment. This novel bank of 62 PDX models of TNBC provides a valuable resource for biomarker discovery and preclinical therapeutic trials aimed at improving neoadjuvant response rates for patients with TNBC.

Application of Artificial Intelligence to Plasma Metabolomics Profiles to Predict Response to Neoadjuvant Chemotherapy in Triple-Negative Breast Cancer

There is a need to identify biomarkers predictive of response to neoadjuvant chemotherapy (NACT) in triple-negative breast cancer (TNBC). We previously obtained evidence that a polyamine signature in the blood is associated with TNBC development and progression. In this study, we evaluated whether plasma polyamines and other metabolites may identify TNBC patients who are less likely to respond to NACT. Pre-treatment plasma levels of acetylated polyamines were elevated in TNBC patients that had moderate to extensive tumor burden (RCB-II/III) following NACT compared to those that achieved a complete pathological response (pCR/RCB-0) or had minimal residual disease (RCB-I). We further applied artificial intelligence to comprehensive metabolic profiles to identify additional metabolites associated with treatment response. Using a deep learning model (DLM), a metabolite panel consisting of two polyamines as well as nine additional metabolites was developed for improved prediction of RCB-II/III. The DLM has potential clinical value for identifying TNBC patients who are unlikely to respond to NACT and who may benefit from other treatment modalities.

Imaging of Noncalcified Ductal Carcinoma In Situ

Ductal carcinoma in situ (DCIS) is a commonly encountered malignancy, accounting for approximately 20% of new breast cancer diagnoses in the United States. DCIS is characterized by a proliferation of tumor cells within the terminal duct lobular unit with preservation of the basement membrane. Typically nonpalpable and asymptomatic, DCIS is most often detected as calcifications on screening mammography. However, DCIS may also be noncalcified. When compared to calcified DCIS, noncalcified DCIS is more likely to be symptomatic, with patients most often presenting with nipple discharge or a palpable mass. Diagnosing noncalcified DCIS is challenging since it may be occult or subtle on mammography, and ultrasound findings can be nonspecific and may be interpreted as benign fibrocystic changes. In cases with a calcified component of DCIS, the extent of DCIS may be underestimated by mammography because not all involved areas may calcify. Breast magnetic resonance imaging (MRI), although less readily available than mammography and ultrasound, is advantageous in detecting noncalcified DCIS, especially high grade DCIS, which may not develop microcalcifications. MRI relies on abnormal contrast uptake due to tumor vascularity and changes in vessel density and permeability. This pictoral review presents the spectrum of imaging findings of noncalcified DCIS to assist radiologists in accurately detecting and describing its key imaging findings. Utilizing different modalities, we review the differential diagnoses for noncalcified DCIS, show illustrative cases of noncalcified DCIS, and discuss the importance of this entity.

Early ultrasound evaluation identifies excellent responders to neoadjuvant systemic therapy among patients with triple-negative breast cancer

BACKGROUND

Heterogeneity exists in the response of triple-negative breast cancer (TNBC) to standard anthracycline (AC)/taxane-based neoadjuvant systemic therapy (NAST), with 40% to 50% of patients having a pathologic complete response (pCR) to therapy. Early assessment of the imaging response during NAST may identify a subset of TNBCs that are likely to have a pCR upon completion of treatment. The authors aimed to evaluate the performance of early ultrasound (US) after 2 cycles of neoadjuvant NAST in identifying excellent responders to NAST among patients with TNBC.

METHODS

Two hundred fifteen patients with TNBC were enrolled in the ongoing ARTEMIS (A Robust TNBC Evaluation Framework to Improve Survival) clinical trial. The patients were divided into a discovery cohort (n = 107) and a validation cohort (n = 108). A receiver operating characteristic analysis with 95% confidence intervals (CIs) and a multivariate logistic regression analysis were performed to model the probability of a pCR on the basis of the tumor volume reduction (TVR) percentage by US from the baseline to after 2 cycles of AC.

RESULTS

Overall, 39.3% of the patients (42 of 107) achieved a pCR. A positive predictive value (PPV) analysis identified a cutoff point of 80% TVR after 2 cycles; the pCR rate was 77% (17 of 22) in patients with a TVR ≥ 80%, and the area under the curve (AUC) was 0.84 (95% CI, 0.77-0.92; P < .0001). In the validation cohort, the pCR rate was 44%. The PPV for pCR with a TVR ≥ 80% after 2 cycles was 76% (95% CI, 55%-91%), and the AUC was 0.79 (95% CI, 0.70-0.87; P < .0001).

CONCLUSIONS

The TVR percentage by US evaluation after 2 cycles of NAST may be a cost-effective early imaging biomarker for a pCR to AC/taxane-based NAST.

Mimickers of breast malignancy: imaging findings, pathologic concordance and clinical management

Many benign breast entities have a clinical and imaging presentation that can mimic breast cancer. The purpose of this review is to illustrate the wide spectrum of imaging features that can be associated with benign breast diseases with an emphasis on the suspicious imaging findings associated with these benign conditions that can mimic cancer. As radiologic-pathologic correlation can be particularly challenging in these cases, the radiologist’s familiarity with these benign entities and their imaging features is essential to ensure that a benign pathology result is accepted as concordant when appropriate and that a suitable management plan is formulated.

Abstract P2-16-09: Residual cancer burden in patients with early stage triple negative breast cancer who progress on anthracycline-based neoadjuvant chemotherapy in an ongoing clinical trial (ARTEMIS)

BACKGROUND: Current treatment for early stage triple negative breast cancer (TNBC) includes neoadjuvant systemic chemotherapy (NAST), which is used to assess disease biology and the need for adjuvant treatment in case of residual disease at the time of surgery, also known as residual cancer burden (RCB). Patients with TNBC who experience RCB-0 (pathologic complete response [pCR]) or RCB-I after NAST have an excellent prognosis whereas patients with significant residual disease (RCB-II or RCB-III) are at a high risk of relapse. Standard NAST for TNBC achieves pCR in 30-50% of cases. NAST typically consists of anthracycline-based chemotherapy followed or preceded by a taxane +/- carboplatin. Disease progression (PD) is uncommon in TNBC patients receiving NAST and little is known regarding outcomes in patients who have PD during the initial phase of NAST. METHODS: Total 316 TNBC patients were evaluated from two prospectively accrued clinical trials of NAST (NCT02276443 and NCT01334021). The ARTEMIS trial (NCT02276443) aims to improve pCR rates by adding targeted therapy to chemotherapy as the second phase of NAST for those patients who do not experience at least a 70% volumetric reduction after 4 cycles of doxorubicin/cyclophosphamide (AC). Unique histopathologic features including % stromal tumor-infiltrating lymphocytes (sTIL), presence of mesenchymal histology (high vimentin expression by IHC), and androgen receptor expression are used to guide second phase therapy. RESULTS: 31 TNBC patients had PD while receiving AC as the first phase of NAST (10%; 95% CI= 6.69-13.31%). 9 of 31 patients proceeded to standard chemotherapy and all had RCB II/III disease. 22 of 31 patients were enrolled to targeted therapy trials. 6 were treated with the EGFR inhibitor panitumumab + carboplatin/paclitaxel, 9 with atezolizumab + nab-paclitaxel, and 7 with everolimus, bevacizumab, and liposomal doxorubicin (DAE). Of these 22 patients, 3 (13.6%) had pCR/RCB-0, 1 (4.5%) RCB-I and 18 (81.8%) had RCB II/III. All 4 patients who experienced RCB-0/I had T2N0 disease at diagnosis. 2 had sTIL &lt; 5% and 2 patients had 70% sTIL. CONCLUSION: PD is uncommon while receiving NAST. Patients with TNBC and progression on initial NAST with AC are unlikely to achieve pCR or RCB-I status despite subsequent standard chemotherapy. Combination chemotherapy with targeted therapy on clinical trial resulted in a numerically higher rate of pCR+RCB-I (18%) as salvage therapy, but this was not statistically significant and requires confirmation in larger trials.

Citation Format: Haven Garber, Gaiane Rauch, Beatriz Adrada, Rosalind Candelaria, Elizabeth Mittendorf, Alastair Thompson, Jennifer Litton, Senthil Damodaran, Bora Lim, Banu Arun, Naoto Ueno, Vicente Valero, Nuhad Ibrahim, Rashmi Murthy, Debu Tripathy, Helen Piwnica-Worms, Fraser Symmans, Lei Huo, Stacy Moulder. Residual cancer burden in patients with early stage triple negative breast cancer who progress on anthracycline-based neoadjuvant chemotherapy in an ongoing clinical trial (ARTEMIS) [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-16-09.

Abstract P1-10-20: Serial TILs: Evaluating the role of mid-treatment tumor infiltrating lymphocytes (TIL) in predicting pathologic complete response (pCR) in early-stage triple negative breast cancer (TNBC)

Introduction High levels of TIL at baseline are associated with higher pCR rates and better overall survival in TNBC. Recent studies have also indicated that higher TIL in post-NACT residual disease in TNBC are an important independent predictor of improved survival. We evaluated the role of mid-treatment (post-AC; Adriamycin/Cyclophosphamide) TIL in predicting pCR rates in early-stage TNBC. Methods Of 242 patients with stage I-III TNBC enrolled in the ARTEMIS trial (NCT02276443), 156 patients had pre-AC TIL and pCR status available for this analysis. Both pre-and post-AC TIL counts were available in 29 patients. Post-AC TIL counts for the remaining patients were imputed using linear regression with age, race, stage III, vimentin &gt;50% and post-AC tumor volume reduction. Using these imputed TIL counts we evaluated the association of post-AC TIL with pCR. We also evaluated the change in TIL before and after treatment with AC. Results At baseline the median TIL count was 10% (n=156). In the post-AC samples, the median TIL count was 5%. Using imputed TIL counts, we did not conclude that post-AC TIL was associated with pCR (p= 0.28). Using a cut-point of 15% TIL, our analysis showed that baseline TIL is more strongly correlated with pCR than post-AC TIL (Table 1). In our univariable logistic regression, both baseline TIL and the difference in TIL pre-and post- treatment were significantly associated with pCR (p= 0.0015 and p=0.0068, respectively), however in the multivariable analysis only baseline TIL was significant. Our analysis did show that a decrease in TIL from pre- to post-treatment was significantly associated with pCR (p=0.022). However, this measure was not significant in our logistic regression model when pre-TIL was also included. Conclusion Higher pre-treatment TIL correlated more strongly with pCR rate when compared to post-AC TIL. Pre-treatment high TIL was associated with pCR regardless of changes in TIL pre and post treatment.

Table 1. Changes in TIL before and after treatmentBaseline TILPost-AC TILN#pCR (%)LowLow6217 (27%)LowHigh4012 (30%)HighLow2513 (52%)HighHigh2916 (55%)TIL; Low: &lt;15, High &gt;15

Citation Format: Nour Abuhadra, Kenneth Hess, Jennifer Litton, Gaiane Rauch, Alastair Thompson, Bora Lim, Beatriz Adrada, Elizabeth Mittendorf, Senthil Damodaran, Rosalind Candelaria, Banu Arun, Wei Tse Yang, Naoto Ueno, Lumarie Santiago, Rashmi Murthy, Nuhad Ibrahim, Sahin Aysegul, William Symmans, Lei Huo, Stacy Moulder. Serial TILs: Evaluating the role of mid-treatment tumor infiltrating lymphocytes (TIL) in predicting pathologic complete response (pCR) in early-stage triple negative breast cancer (TNBC) [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P1-10-20.

Abstract P3-01-01: Circulating tumor cells (CTCs) after neoadjuvant chemotherapy for triple negative breast cancer (TNBC)

Background: ARTEMIS (A Randomized, TNBC Enrolling trial to confirm Molecular profiling Improves Survival) is a randomized trial to determine if precision guided neoadjuvant chemotherapy (NAC) impacts rates of pathologic complete response in the breast and axillary nodes (pCR). We hypothesized that CTCs in peripheral blood after completion of NAC would provide prognostic information beyond pCR alone in TNBC patients.

Methods: Blood was assessed for CTCs after NAC as part of two IRB approved studies, ARTEMIS (2014 – 0185/PA15-1050), and LAB04-0698. CTCs were identified using the Cell Search® System (Menarini Silicon Biosystems). Samples with one or more cells, also having morphologic criteria for malignancy, were deemed CTC positive. Log-rank test and Cox regression analysis were applied to evaluate associations between CTC positive, pCR, and overall survival.

Results: pCR was achieved in 24/68 (35%) patients with TNBC. Twenty four patients (35%) were CTC positive. Three year overall survival was evaluated in 4 groups of patients: pCR and no CTCs (n=20), pCR and CTC positive (n=4), non-pCR and no CTCs (n=24) and non-pCR and CTC positive (n=20). Three year overall survival was higher in the pCR and no CTCs cohort (100%), compared to pCR and CTC positive (50%), non-pCR and no CTCs (83%), non-pCR and CTC positive (19%); log rank p&lt;0.0001. In the non-pCR and CTC positive patient cohorts, the presence of CTCs was associated with significant risk of death at 3 years [hazard ratio of 12.3 (95% CI 3.4-454, p=0.00002)], whereas a favorable, but non-significant trend was noted for pCR [hazard ratio of 0.2 (95% CI 0.0, 1.4, p=0.11)].

Conclusion: The identification of CTCs after NAC has prognostic significance beyond that of pCR, and should be considered in evaluation of patients for clinical trials of adjuvant therapies.

Citation Format: Lucci A, Hall C, Hess K, Ravenberg E, Clayborn A, Mittendorf E, Rauch G, Candelaria R, Moulder S, Thompson A. Circulating tumor cells (CTCs) after neoadjuvant chemotherapy for triple negative breast cancer (TNBC) [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 P3-01-01.

Abstract P6-02-04: Ultrasound assessment of residual disease after neoadjuvant chemotherapy (NACT) in node positive triple negative breast cancer (TNBC)

Purpose: To determine accuracy of preoperative ultrasound after NACT to predict residual disease in triple negative breast cancer (TNBC) patients with confirmed axillary nodal metastasis.

Methods: This is an institutional review board approved retrospective study of TNBC patients who received NACT at MD Anderson Cancer Center from January 1999 - June 2015. We identified 327 TNBC patients who had cytologically confirmed breast and nodal disease at baseline evaluation and had preoperative ultrasound evaluation of residual disease. Ultrasound response was divided in tree categories: radiologic complete response (rCR) - complete resolution of the malignant mass); near-rCR - no discernible mass, only an isoechoic flat tumoral bed); and residual disease (RD) - a discernible mass is seen. Axillary ultrasound images were evaluated for lymph node size, cortical thickness and residual morphological type after NAC (type I-VI). Ultrasound breast and axillary findings were compared with final surgical pathology.

Results: In 89 cases (27%), pCR was achieved. 74% (242/327) were unifocal and 26% (86/327) multifocal. Ultrasound rCR was seen in 11% patients (36/327). Of those, 64% (23/36) showed pCR and 36% (13/36) showed residual disease. Ultrasound near-rCR was seen in 26% (84/327). Of those, pCR was seen 49 % (41/84) and residual disease in 51% (43/84). Residual disease was seen in 63% (207/327), 12% (25/207) showed pCR and 88% (182/207) showed residual disease. Regarding axillary lymph nodes, long axis diameter mean was 1.57 cm for patients with pCR and 1.6 cm for no pCR, short axis diameter mean was 0.67 cm for pCR and 0.87 cm for no pCR. Cortical thickness mean was 2 mm for pCR versus 9 mm for no pCR.

Sensitivity of ultrasound for assessment residual disease (ultrasound was considered positive if either breast ultrasound or axillary ultrasound showed residual disease) was 97%. Specificity is 22.47% with a NPV of 74% and PPV of 77%.

Conclusion: Breast and axillary ultrasound performed after NACT showed low specificity but high sensitive to detect residual disease. rCR and near rCR were related with pCR in 64% and 49 % of the cases respectively.

Citation Format: Adrada BE, Valero V, Reddy SM, Barcenas CH, Candelaria R, Wei W, Rauch GM. Ultrasound assessment of residual disease after neoadjuvant chemotherapy (NACT) in node positive triple negative breast cancer (TNBC) [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 P6-02-04.

Abstract P6-02-10: Early ultrasound evaluation for prediction of treatment response to neoadjuvant chemotherapy in triple negative breast cancer patients

Background: Triple negative breast cancer (TNBC) is molecularly heterogeneous disease. Genomic profiling to identify the distinct TNBC subtypes is costly with long turnaround time. Early ultrasound after two cycles of neoadjuvant chemotherapy (NAC) has the potential to identify patients who are likely to have pathological complete response. Suspected non-responder patients can undergo comprehensive genetic testing and triaged for specific targeted therapeutic trials.

Aim: To determine the value of ultrasound evaluation after two cycles of NAC to predict complete pathologic response in TNBC breast cancer patients.

Methods: 98 patients enrolled in “A randomized triple Negative Breast Cancer Enrolling Trial to Confirm Molecular Profiling Improves Survival” (Artemis) at the University of Texas MD Anderson Cancer Center had ultrasound evaluation before treatment and after two cycles of NAC (Adriamycin and Cyclophosphamide). Three-dimensional measurements of the tumor were obtained at baseline and after 2 cycles of the NAC. Change in the tumor volume after 2 cycles of NAC was calculated. Residual cancer Volume (RCB) was calculated based on the final histopathology at surgery. Linear regression analysis evaluated associations between residual cancer burden (RCB) and change in volume of the index tumor.

Results: Median tumor size at diagnosis was 3 cm, range 0.6-11.9cm. Median size after two cycles was 2 cm, range 0.6-12.8 cm. RCB 0-I was seen in 55% of patients (54/98). Linear regression analysis demonstrated that of 22 patients with volume reduction &gt;75%, 18 patients (82%) had RCB0-I (95%CI, 61%-93%).

Conclusion: Our data suggest that ultrasound exam after 2 cycles of NAC can identify TNBC patients who are unlikely to respond to standard NAC. These non-responder TNBC patients can be triaged for additional genetic testing and subsequent targeted clinical trials. Study on the larger number of patients is currently on the way.

Citation Format: Adrada BE, Candelaria R, Moulder S, Lane D, Santiago L, Arribas E, Hess KR, Valero V, Thompson A, Helgason T, Ravenberg E, Yang W, Rauch GM. Early ultrasound evaluation for prediction of treatment response to neoadjuvant chemotherapy in triple negative breast cancer patients [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 P6-02-10.

Abstract P5-05-01: A molecularly annotated collection of breast cancer patient-derived xenograft models aligned with ongoing clinical trials built from fine needle aspiration samples throughout neoadjuvant treatment

BACKGROUND: Patient-derived xenograft (PDX) models of breast cancer replicate the diverse histologic and molecular features of patient tumors and provide a renewable source of human tumor tissue. However, collection of tissue by core needle biopsy is problematic due to patient discomfort, bleeding risk and the limited number of passes a patient can tolerate. Several studies have catalogued the maintenance of molecular features of patient tumors in PDX models of breast cancer.

METHODS: To support the neoadjuvant molecular diagnostic and drug development program in triple negative breast cancer (TNBC), a pilot study was conducted to determine if fine needle aspiration (FNA) could be used for building PDX models. Subsequently, PDX models are being established in alignment with ongoing clinical trials at MDACC. The molecular evolution of patient's tumors, matched with PDXs engrafted from their tumors, is under study throughout the neoadjuvant treatment of TNBC using RNA sequencing, whole-exome sequencing, deep sequencing of cancer genes, and histologic analyses.

RESULTS: To date, 20 established PDX models have been developed and stable PDX models continue to be generated at a rate of 2-3 per month. Several of these models are derived from serial FNAs derived from patients throughout neoadjuvant treatment. These models retain histologic and molecular features of the original patient tumors. Serial patient biopsies, matched with PDX models, have enabled measurement of the mutational and transcriptomic evolution in vivo of TNBC undergoing neoadjuvant treatment.

We have standardized the use of FNAs to generate PDX models both pre- and post-neoadjuvant therapy in the following ongoing neoadjuvant clinical trials:

1. MDACC 2014-0185 (PI Stacy Moulder, 360 patients), 'ARTEMIS: A Randomized TNBC-Enrolling trial to confirm Molecular profiling Improves Survival'

2. MDACC 2014-0045 (PI Jennifer Litton, 20+ patients), 'A pilot study of BMN673 as a neoadjuvant study in patients with a diagnosis of invasive breast cancer and a deleterious BRCA mutation'

CONCLUSION: We demonstrated that PDX models from tissue collected by FNA recapitulate the biology and clinical course of the patient's tumor. Sequencing analyses revealed that neoadjuvant chemotherapy and PDX engraftment enrich for cancer gene mutations. We observe association of the rate of successful PDX engraftment with clinical parameters such as the patient's residual cancer burden (RCB) status at the time of surgery (upon completion of neoadjuvant treatment). In addition, we observe that PDX models derived from serial patient biopsies throughout treatment are more resistant to chemotherapy treatment. These models recapitulate the variety of chemotherapy responses observed in patients with TNBC and serve as powerful tools for preclinical biomarker and discovery studies.

Citation Format: Echeverria GV, Cai S, Tu Y, McCoy A, Lau R, Redwood A, Rauch G, Adrada B, Candelaria R, Santiago L, Thompson A, Litton J, Moulder S, Symmans F, Chang JT, Piwnica-Worms H. A molecularly annotated collection of breast cancer patient-derived xenograft models aligned with ongoing clinical trials built from fine needle aspiration samples throughout neoadjuvant treatment [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-05-01.

Abstract OT3-2-05: Improving outcomes in triple-negative breast cancer (TNBC) using molecular triaging and diagnostic imaging to guide neoadjuvant therapy

BACKGROUND:

Known disparities exist in patients with TNBC treated using neoadjuvant chemotherapy (NACT) with 30-50% having excellent response to treatment (pCR/RCB-I) and good survival prognosis, while 50-70% demonstrate marked residual disease (RCB-II-III) with significantly worse prognosis. Lack of response early into NACT also indicates a low chance (5%) of achieving pCR. Thus, it is important to develop diagnostic platforms predictive of pCR, in order to direct patients with responsive disease toward standard NACT and non-responsive disease toward experimental therapies within clinical trials.

TRIAL DESIGN

This study will determine the impact of predicting response to NACT using both molecular and imaging diagnostics and will determine if offering a clinical trial of selected targeted therapy will impact outcomes (as measured by pCR and RCB) in predicted non-responsive disease. An algorithm that incorporates pre-defined genomic signatures will determine predicted sensitivity to chemotherapy (JAMA, 2011; 305:1873-81). All patients will undergo biopsy of the primary tumor for molecular analyses, but will then be randomized 2:1 to know these results (Arm A) versus not (Arm B). All patients will begin anthracycline-based NACT with diagnostic imaging to assess response after 4 cycles. Patients who fit molecular/imaging criteria for non-responsive disease will be offered a clinical trial based upon molecular profiling (Arm A) or based upon physician/patient choice (Arm B). Patients who fit criteria for responsive disease in either arm will continue with taxane based NACT.

ELIGIBILITY CRITERIA

INCLUSION: Candidate for biopsy of the primary tumor site; tumor size &gt; 1.5 cm diameter; TNBC by standard pathologic assays; &gt;18 years of age; LVEF &gt; 50%; adequate organ and bone marrow function

EXCLUSION: Stage IV disease; history of invasive cancer within 5 years; excisional biopsy of the primary tumor; biopsy site changes that limit response assessment; medically unfit for chemotherapy; prior anthracycline; &gt;grade II neuropathy; Zubrod performance status of &gt;2; history of serious cardiac event

PRIMARY AIM

Primary Aim: to prospectively determine the impact of implementation of a research platform that includes molecular (genomic) testing from a primary tumor biopsy to predict response, and diagnostic imaging to assess response to standard NACT in patients with localized invasive TNBC. Secondary Aims: compare rates of clinical trial enrollment between study arms, compare DFS, integrated "prospective-retrospective" biomarker analysis, correlative science studies to identify therapeutic targets for resistant disease

STATISTICAL METHODS AND TARGET ACCRUAL

Success will be defined as an improvement in the rate of excellent pathologic response (pCR/RCB-I) from 50%--&gt;64% using the triaging platform. A maximum of 360 patients will be randomized 2:1 to the experimental arm vs. the control arm using a group sequential design with one-sided O’Brien-Fleming boundaries, with up to two equally spaced binding interim tests for both futility and superiority and one final test, having an overall Type I error .05 and power .80 to detect a response rate improvement from a null rate of .50 to a target value of .642.

Citation Format: Stacy Moulder-Thompson, Wei Yang, Naoto T Ueno, Joe Ensor, Vicente Valero, Ricardo Alvarez, Jennifer Litton, Rashmi Murthy, Nuhad Ibrahim, Banu Arun, Beth Mittendorf, Kelly Hunt, Funda Meric-Bernstam, Helen Piwnica-Worms, Rosalind Candelaria, Debu Tripathy, Fraser Symmans. Improving outcomes in triple-negative breast cancer (TNBC) using molecular triaging and diagnostic imaging to guide neoadjuvant therapy [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr OT3-2-05.

Second-look US examination of MR-detected breast lesions

PURPOSE

To review our institutional experience in using second-look ultrasound (SLUS) to identify breast lesions initially detected on MR imaging that were indeterminate or suspicious for malignancy.

METHODS

This Health Insurance Portability and Accountability Act compliant retrospective review included 83 women with 131 lesions initially identified as indeterminate or suspicious for malignancy on MR imaging from February 1, 2008 through July 31, 2009. An SLUS correlate was confirmed on the basis of concordant location, size, and morphologic features. The detection rate of SLUS was determined. Patients' demographics, lesion size, and MR imaging morphologic features (focus, mass, non-masslike) were reviewed to identify which factors led to successful detection on SLUS. Likelihood ratio χ(2) tests were used for statistical analysis.

RESULTS

SLUS correlates were found for 88 of 131 (67%) lesions initially detected on MR imaging; 27 of 88 (31%) were malignant. SLUS detected foci (67%) and masses (73%) more frequently than it did non-masslike lesions (54%). The detection rate of SLUS was independent of lesion size on MR imaging. Malignant lesions were not more likely than benign lesions to be detected on SLUS (61% versus 70%).

CONCLUSIONS

SLUS provides value in the clinical workup of breast lesions that are indeterminate or suspicious for malignancy. It identified two thirds of the MR-detected lesions evaluated and permitted performance of US-guided needle biopsy on 70 of 88lesions. The likelihood of finding MR-detected lesions on SLUS was significantly higher for foci and masses than for non-masslike lesions (P < 0.05).

O-glycosylation of Sp1 and transcriptional regulation of the calmodulin gene by insulin and glucagon

Both insulin and glucagon stimulate steady-state levels of Sp1 transcription factor, but only insulin stimulates transcription of the calmodulin (CaM) gene in liver. Because O-glycosylation of Sp1 by O-linked N-acetylglucosamine (O-GlcNAc) is thought to regulate its ability to activate transcription, we assayed the levels of Sp1 with anti-Sp1 and anti-O-GlcNAc antibodies in Western blots by use of extracts of H-411E liver cells treated with insulin (10,000 microU/ml) or glucagon (1.5 x 10(-5) M). We also assessed subcellular localization of the native and glycosylated Sp1 in H411E cells treated with either hormone in the presence of deoxynorleucine (DON, an indirect inhibitor of O-glycosylation) or streptozotocin (STZ, an indirect stimulator of O-glycosylation). Insulin stimulated both total and O-GlcNAc-modified Sp1 primarily in the nucleus and induced CaM gene transcription (P < 0.0001). In contrast, glucagon promoted accumulation of Sp1 in the cytoplasm but not the nucleus, without significantly stimulating (P = not significant) either its O-glycosylation or transcription of the CaM gene. DON inhibited O-glycosylation of Sp1 and its ability to migrate to the nucleus and transactivate CaM gene transcription. In contrast, cotreatment of cells with STZ and glucagon enhanced O-glycosylation of Sp1, promoting its migration to the nucleus and resulting in increased CaM gene transcription. Thus O-glycosylation of Sp1 by insulin, but not glucagon, apparently enhances its (Sp1) nuclear recruitment and results in activation of CaM gene transcription.