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RNAseq gene expression changes in BRCA1-I26A mutant MEFs (Oct1 CRISPR vs control).

Supp. Figure S1 Differential metabolite levels in BRCA1 I26A compared to normal MEFs. Supp. Figure S2 Control immunofluorescence microscopy images using Oct1-deficient MEFs. Supp. Figure S3 Small increase in Oct1 proteins levels in MEFs with a C-terminal BRCA1 mutation. Supp. Figure S4 Equivalent infection rates in Oct1 and control CRISPR infection rates in BRCA1-I26A MEFs. Supp. Figure S5 Quality-control and validation of RNAseq. Supp. Figure S6 CRISPR-mediated Oct1 loss in either BRCA1-I26A MEFs or MCF-7 cells minimally affects HIF-1α and c-Myc levels. Supp. Figure S7 Equivalent infection rates in Oct1 and control CRISPR infection rates in MCF-7 cells. Supp. Figure S8 MG-132 treatment reveals ubiquitylated Oct1 bands in the presence of urea. Supp. Figure S9 O2 consumption rate (OCR) was assessed in MCF-7 cells transduced with either empty vector control (EV), or viruses expressing WT or K9/403R Oct1. Supp. Figure S10 Oct1 protein stability in WT and I26A MEFs. Supp. Figure S11 Immunoprecipitating in vitro ubiquitylation assay products with control rabbit IgG antibodies results in recovery of background ubiquitylation. Supp. Figure S12 The same as in Figure 6A except with individual datapoints (Supplemental Table S4) superimposed. Supp. Figure S13 Elevated Oct1 (Pou2f1) mRNA levels correlate with poor patient outcome in gastric but not breast cancer.

The tumor suppressor BRCA1 regulates the DNA damage response (DDR) and other processes that remain incompletely defined. Among these, BRCA1 heterodimerizes with BARD1 to ubiquitylate targets via its N-terminal E3 ligase activity. Here, it is demonstrated that BRCA1 promotes oxidative metabolism by degrading Oct1 (POU2F1), a transcription factor with proglycolytic and tumorigenic effects. BRCA1 E3 ubiquitin ligase mutation skews cells toward a glycolytic metabolic profile while elevating Oct1 protein. CRISPR-mediated Oct1 deletion reverts the glycolytic phenotype. RNA sequencing (RNAseq) confirms deregulation of metabolic genes downstream of Oct1. BRCA1 mediates Oct1 ubiquitylation and degradation, and mutation of two ubiquitylated Oct1 lysines insulates the protein against BRCA1-mediated destabilization. Oct1 deletion in MCF-7 breast cancer cells does not perturb growth in standard culture, but inhibits growth in soft agar and xenograft assays. In primary breast cancer clinical specimens, Oct1 protein levels correlate positively with tumor aggressiveness and inversely with BRCA1. These results identify BRCA1 as an Oct1 ubiquitin ligase that catalyzes Oct1 degradation to promote oxidative metabolism and restrict tumorigenicity. Mol Cancer Res; 16(3); 439–52. ©2018 AACR.

Legends for Supplementary Figures S1-S13, and Tables S1-S4

Supplemental Figure Legend

Supplemental Figures 1-7 include a graphical outline of the study, graphs depicting probe performance, correlations between MHCII and TIL scores, ROC statistics, and additional Kaplan Meier curves.

Supplemental Figure: Description of sample sets for the DNAseq and RNAseq experiments.

Equations to calculate sample size in a homozygous discordant design. Supplemental Table: Sample size requirements (n in each group)

The findings from genome-wide association studies hold enormous potential for novel insight into disease mechanisms. A major challenge in the field is to map these low-risk association signals to their underlying functional sequence variants (FSV). Simple sequence study designs are insufficient, as the vast numbers of statistically comparable variants and a limited knowledge of noncoding regulatory elements complicate prioritization. Furthermore, large sample sizes are typically required for adequate power to identify the initial association signals. One important question is whether similar sample sizes need to be sequenced to identify the FSVs. Here, we present a proof-of-principle example of an extreme discordant design to map FSVs within the 2q33 low-risk breast cancer locus. Our approach employed DNA sequencing of a small number of discordant haplotypes to efficiently identify candidate FSVs. Our results were consistent with those from a 2,000-fold larger, traditional imputation-based fine-mapping study. To prioritize further, we used expression-quantitative trait locus analysis of RNA sequencing from breast tissues, gene regulation annotations from the ENCODE consortium, and functional assays for differential enhancer activities. Notably, we implicate three regulatory variants at 2q33 that target CASP8 (rs3769823, rs3769821 in CASP8, and rs10197246 in ALS2CR12) as functionally relevant. We conclude that nested discordant haplotype sequencing is a promising approach to aid mapping of low-risk association loci. The ability to include more efficient sequencing designs into mapping efforts presents an opportunity for the field to capitalize on the potential of association loci and accelerate translation of association signals to their underlying FSVs. Cancer Res; 76(7); 1916–25. ©2016 AACR.

Approximately 40% of patients with stage I–III triple-negative breast cancer (TNBC) recur after standard treatment, whereas the remaining 60% experience long-term disease-free survival (DFS). There are currently no clinical tests to assess the risk of recurrence in TNBC patients. We previously determined that TNBC patients with MHC class II (MHCII) pathway expression in their tumors experienced significantly longer DFS. To translate this discovery into a clinical test, we developed an MHCII Immune Activation assay, which measures expression of 36 genes using NanoString technology. Preanalytical testing confirmed that the assay is accurate and reproducible in formalin-fixed paraffin-embedded (FFPE) tumor specimens. The assay measurements were concordant with RNA-seq, MHCII protein expression, and tumor-infiltrating lymphocyte counts. In a training set of 44 primary TNBC tumors, the MHCII Immune Activation Score was significantly associated with longer DFS (HR = 0.17; P = 0.015). In an independent validation cohort of 56 primary FFPE TNBC tumors, the Immune Activation Score was significantly associated with longer DFS (HR = 0.19; P = 0.011) independent of clinical stage. An Immune Activation Score threshold for identifying patients with very low risk of relapse in the training set provided 100% specificity in the validation cohort. The assay format enables adoption as a standardized clinical prognostic test for identifying TNBC patients with a low risk of recurrence. Correlative data support future studies to determine if the assay can identify patients in whom chemotherapy can be safely deescalated and patients likely to respond to immunotherapy.Significance:The MHCII Immune Activation assay identifies TNBC patients with a low risk of recurrence, addressing a critical need for prognostic biomarker tests that enable precision medicine for TNBC patients.

Supplementary Methods, Figures 1-7 from Protein Arginine Methyltransferase 5 Accelerates Tumor Growth by Arginine Methylation of the Tumor Suppressor Programmed Cell Death 4

Models that recapitulate the complexity of human tumors are urgently needed to develop more effective cancer therapies. We report a bank of human patient-derived xenografts (PDXs) and matched organoid cultures from tumors that represent the greatest unmet need: endocrine-resistant, treatment-refractory and metastatic breast cancers. We leverage matched PDXs and PDX-derived organoids (PDxO) for drug screening that is feasible and cost-effective with in vivo validation. Moreover, we demonstrate the feasibility of using these models for precision oncology in real time with clinical care in a case of triple-negative breast cancer (TNBC) with early metastatic recurrence. Our results uncovered a Food and Drug Administration (FDA)-approved drug with high efficacy against the models. Treatment with this therapy resulted in a complete response for the individual and a progression-free survival (PFS) period more than three times longer than their previous therapies. This work provides valuable methods and resources for functional precision medicine and drug development for human breast cancer.

Fibromatosis of the breast is a rare, benign locally infiltrative tumor without metastatic potential. Patients typically present with a painless, palpable, firm breast mass, which may be mobile or fixed to the pectoralis muscle. While some cases are related to familial mutations in the adenomatous polyposis coli (APC) gene, the majority are sporadic due to somatic mutations or prior injury to the breast tissue. On mammography, fibromatosis is typically seen as an irregular, dense, spiculated mass. US demonstrates a hypoechoic, irregular mass with indistinct margins. Fibromatosis is indistinguishable from breast cancer on imaging, and core biopsy is required for definitive diagnosis. Wide local excision is the historical standard for treatment; however, recurrence rates are high, and other emerging therapies are being explored. This article reviews the clinical features, imaging and histopathologic findings, along with brief overview of management.

BackgroundMetastatic breast cancer is a deadly disease with a low 5-year survival rate. Tracking metastatic spread in living patients is difficult, and thus poorly understood.ResultsVia rapid autopsy, we have collected 30 tumor samples over 3 timepoints and across 8 organs from a triple-negative metastatic breast cancer patient. The large number of sites sampled, together with deep whole genome sequencing and advanced computational analysis, allowed us to comprehensively reconstruct the tumor’s evolution at subclonal resolution. The most unique, previously not reported aspect of the tumor’s evolution we observed in this patient was the presence of “subclone incubators”, i.e. already metastatic sites where substantial tumor evolution occurred before colonization of additional sites and organs by subclones that evolved at the incubator site. Overall, we identified four discrete waves of metastatic expansions, each of which resulted in a number of new, genetically similar metastasis sites that also enriched for particular organs (e.g. abdominal vs bone and brain). The lung played a critical role in facilitating metastatic spread in this patient: the lung was the first site of metastatic escape from the primary breast lesion; subclones at this site were the source of all four subsequent metastatic waves; and multiple sites in the lung acted as subclone incubators. Finally, functional annotation revealed that many known driver or metastasis-promoting tumor mutations in this patient were shared by some, but not all metastatic sites, highlighting the need for more comprehensive surveys of a patient’s metastases for effective clinical intervention.ConclusionsOur analysis revealed the presence of substantial tumor evolution at metastatic incubator sites, with potentially important clinical implications. Our study demonstrated that sampling of a large number of metastatic sites affords unprecedented detail for studying metastatic evolution.

OBJECTIVES Accurate evaluation of human epidermal growth factor receptor 2 (HER2) in breast cancer is critical. METHODS HER2 fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) tests were performed on 52 cases using a US Food and Drug Administration (FDA)-approved kit (HercepTest, FDA kit) and a laboratory-developed test (LDT) with the HercepTest antibody and a Leica Bond automated stainer. RESULTS By FISH, 22 were HER2 positive, 29 were negative, and one was equivocal. Of the 22 HER2 FISH-positive cases, five were negative by the FDA kit and none by LDT. The five discrepant cases were retested using the same FDA kit in another Clinical Laboratory Improvement Amendments-certified laboratory, and all five cases were still negative. None of the 29 HER2 FISH-negative cases were positive by the FDA kit or LDT. The overall IHC-FISH concordance rate was 90.4% for the FDA kit and 100% for the LDT. CONCLUSIONS The FDA kit may miss some HER2-positive cases. The LDT has a higher sensitivity and a higher concordance rate with FISH results.

Model systems that recapitulate the complexity of human tumors and the reality of variable treatment responses are urgently needed to better understand cancer biology and to develop more effective cancer therapies. Here we report development and characterization of a large bank of patient-derived xenografts (PDX) and matched organoid cultures from tumors that represent some of the greatest unmet needs in breast cancer research and treatment. These include endocrine-resistant, treatment-refractory, and metastatic breast cancers and, in some cases, multiple tumor collections from the same patients. The models can be grown long-term with high fidelity to the original tumors. We show that development of matched PDX and PDX-derived organoid (PDxO) models facilitates high-throughput drug screening that is feasible and cost-effective, while also allowing in vivo validation of results. Our data reveal consistency between drug screening results in organoids and drug responses in breast cancer PDX. Moreover, we demonstrate the feasibility of using these patient-derived models for precision oncology in real time with patient care, using a case of a triple negative breast cancer with early metastatic recurrence as an example. Our results uncovered an FDA-approved drug with high efficacy against the models. Treatment with the PDxO-directed therapy resulted in a complete response for the patient and a progression-free survival period more than three times longer than her previous therapies. This work provides valuable new methods and resources for functional precision medicine and drug development for human breast cancer.Graphical Abstract

Triple negative breast cancer (TNBC) is an aggressive breast cancer subtype. Recent studies have shown that MHC class II (MHCII) expression and tumor infiltrating lymphocytes are important prognostic factors in patients with TNBC, although the relative importance of lymphocyte subsets and associated protein expression is incompletely understood. NanoString Digital Spatial Profiling (DSP) allows for spatially resolved, highly multiplexed quantification of proteins in clinical samples. In this study, we sought to determine if DSP could be used to characterize expression of MHCII and other immune related proteins in tumor epithelial versus stromal compartments of patient-derived TNBCs (N = 10) using a panel of 39 markers. We confirmed that a subset of TNBCs have elevated expression of HLA-DR in tumor epithelial cells; HLA-DR expression was also significantly higher in the tumors of patients with long-term disease-free survival when compared to patients that relapsed. HLA-DR expression in the epithelial compartment was correlated with high expression of CD4 and ICOS in the stromal compartment of the same tumors. We also identified candidate protein biomarkers with significant differential expression between patients that relapsed versus those that did not. In conclusion, DSP is a powerful method that allows for quantification of proteins in the immune microenvironment of TNBCs.

Advances in imaging and early cancer detection have increased interest in magnetic resonance (MR) guided focused ultrasound (MRgFUS) technologies for cancer treatment. MRgFUS ablation treatments could reduce surgical risks, preserve organ tissue/function, and improve patient quality of life. However, surgical resection and histological analysis remain the gold standard to assess cancer treatment response. For non-invasive ablation therapies such as MRgFUS, the treatment response must be determined through MR imaging biomarkers. However, current MR biomarkers are inconclusive and have not been rigorously evaluated against histology via accurate registration. Existing registration methods rely on anatomical features to directly register in vivo MR and histology. For MRgFUS applications in anatomies such as liver, kidney, or breast, anatomical features independent from treatment features are often insufficient to perform direct registration. We present a novel MR to histology registration workflow that utilizes intermediate imaging and does not rely on these independent features. The presented workflow yields an overall registration accuracy of 1.00 +/- 0.13 mm. The developed registration pipeline is used to evaluate a common MRgFUS treatment assessment biomarker against histology. Evaluating MR biomarkers against histology using this registration pipeline will facilitate validating novel MRgFUS biomarkers to improve treatment assessment without surgical intervention., Comment: 12 pages, 5 figures, 2 tables

BACKGROUND Although the proportion of triple-negative breast cancers (TNBCs) diagnosed among older women is low, the number of TNBC cases is substantial because of the high incidence of breast cancer after the age of 65 years. The molecular features of TNBC in this age group have not been well described. METHODS This study examined a population-based cohort of women with stage I to III TNBC diagnosed between the ages of 25 and 91 years with the PAM50 gene expression subtyping assay. The concordance between the TNBC classification by immunohistochemistry and the gene expression classification by PAM50, the expression of individual genes, and 5-year recurrence and breast cancer mortality in older women (≥65 years old) and younger women (

Background: Breast tumor subtyping has failed to provide impact in susceptibility genetics. The PAM50 assay categorizes breast tumors into: Luminal A, Luminal B, HER2-enriched and Basal-like. However, tumors are often more complex than simple categorization can describe. The identification of heritable tumor characteristics has potential to decrease heterogeneity and increase power for gene finding. Methods: We used 911 sporadic breast tumors with PAM50 expression data to derive tumor dimensions using principal components (PC). Dimensions in 238 tumors from high-risk pedigrees were compared with the sporadic tumors. Proof-of-concept gene mapping, informed by tumor dimension, was performed using Shared Genomic Segment (SGS) analysis. Results: Five dimensions (PC1-5) explained the majority of the PAM50 expression variance: three captured intrinsic subtype, two were novel (PC3, PC5). All five replicated in 745 TCGA tumors. Both novel dimensions were significantly enriched in the high-risk pedigrees (intrinsic subtypes were not). SGS gene-mapping in a pedigree identified a 0.5 Mb genome-wide significant region at 12q15. This region segregated through 32 meioses to 8 breast cancer cases with extreme PC3 tumors (P = 2.6 × 10−8). Conclusions: PC analysis of PAM50 gene expression revealed multiple independent, quantitative measures of tumor diversity. These tumor dimensions show evidence for heritability and potential as powerful traits for gene mapping. Impact: Our study suggests a new approach to describe tumor expression diversity, provides new avenues for germline studies, and proposes a new breast cancer locus. Similar reparameterization of expression patterns may inform other studies attempting to model the effects of tumor heterogeneity. Cancer Epidemiol Biomarkers Prev; 27(6); 644–52. ©2018 AACR.

Background and Objectives: EUS guided core biopsy was once rarely performed but is now entering mainstream practice. Neuroendocrine tumors often warrant core biopsy as sufficient tissue must be obtained to allow for special staining to ensure a correct diagnosis. Traditionally these lesions were sampled with FNA needles. We performed a retrospective pilot study to evaluate the clinical value and efficacy of the a new EUS core needle biopsy needle as compared to a standard EUS FNA needle in the evaluation of patients with known or suspected neuroendocrine tumors. Methods: A retrospective analysis of the first 10 patients (between January 2015 and April 2016) to undergo EUS-FNA with the SharkCore® needle at the University of Utah School of Medicine/Huntsman Cancer Center with neuroendocrine tumors. Each case was retrospectively reviewed by a board certified cytopathologist (BLW) for the following cytologic parameters on the aspirate smears or touch/squash preparations: overall cellularity [1 (low) to 3 (high)], percentage of obtained cells that were lesional/representative (50%), relative ease of interpretation [1 (difficult) to 3 (easy)]. Pathologic material and reporting records were also reviewed for each case to confirm the number of needle passes to achieve diagnostic adequacy, the presence or absence diagnostic material on H&E slide (from cell block, if prepared), whether a definitive diagnosis was able to be rendered, and the presence or absence of a true core/core fragments (within the cell block, if prepared). Results: A total of 20 patients underwent EUS-FNA for suspected neuroendocrine lesions. Ten patients underwent either transgastric or transduodenal EUS-FNA with the 22 gauge SharkCore® needle. The comparison cohort of 10 patients underwent either transgastric or transduodenal EUS-FNA with the standard 22 gauge Echotip® needle. The SharkCore® needle required a fewer mean number of needle passes to obtain diagnostic adequacy than the Echotip® (P=0.0074). For cases with cell blocks, the SharkCore® needle produced diagnostic material in 100% of cases, whereas Echotip® produced diagnostic material in 60% of cases. There was no significant difference between specimen cellularity, percentage of lesional material, or ease of interpretation between the two needle types. Conclusion: Our pilot investigation targeting patients with known or suspected pancreatic NETs indicates that the SharkCore® needle shows promise in obtaining suitable tissue for ancillary testing that can allow for more definitive pathologic interpretations on EUS FNA specimens. Fewer passes were needed with the core needle when compared to a standard needle.

Purpose: The sentinel lymph node (SLN) is biopsied during breast conservation surgery (BCS) since it is the first site of metastasis for breast cancer. If malignant, axillary lymph node dissection (ALND) may be performed to remove additional nodes in and around the affected breast, limiting the spread of the malignancy. Often, ALND results in hardship for the patient in the form of further surgeries, having nodes removed that may not be malignant, and in debilitating side effects. Developing a method to analyze SLNs intraoperatively would eliminate additional surgeries and the patient's associated suffering. This research aims to develop the use of high-frequency (HF) ultrasound (20-80 MHz) as a real-time analysis method to determine SLN status during BCS. Background: HF ultrasonic data from BCS tissue specimens were gathered from 73 patients at the Huntsman Cancer Institute, Salt Lake City, UT, immediately following surgery. In addition to 349 margin specimens, data were collected from 78 SLNs, with initial results displaying high statistical measures. A limitation of the SLN analyses, however, was that pathology results were provided only on a per sample basis, whereas the ultrasonic method often tested multiple positions on a node (max = 4, avg = 1.26). Because of the mismatch between the ultrasonic measurements (per position basis) and pathology results (per specimen basis), an ambiguity existed in how to best analyze the data. The aim of this study was to examine the scope of this ambiguity by determining the differences in statistical measures obtained by analyzing the SLN data on a per position basis versus a per specimen basis given the current data available. Method: HF ultrasound parameters extracted from the data were peak density (the number of peaks in the ultrasonic spectra) and attenuation. Both parameters correlate to tissue malignancy, and were used in a multivariate analysis to provide the final results. The statistical measures for the ultrasonic test results were calculated as follows: (1) per position basis: the pathology of each position was determined by the pathology results for the entire specimen; (2) per specimen basis: only one measurement position on each node was selected, based on the highest peak density value, to correlate to the specimen pathology. Results: The analyses revealed that the HF ultrasonic data yielded an accuracy, sensitivity, and specificity of 79.6%, 76.9%, and 80.0%, respectively, for the per position basis, and 84.6%, 87.5%, and 84.3%, respectively, for the per specimen basis. The results indicate that HF ultrasound provides intraoperative detection capabilities competitive with many SLN evaluation methods currently in use, including imprint cytology, frozen-section analysis, and qRT-PCR. Detailed analyses of the SLN pathology slides from the 73-patient study are currently being conducted to improve the correlations between the ultrasound results and histopathology. Image analysis methods are being used to quantify the extent of the malignant tissue in each SLN. This will provide pathology results on a per position basis, and thus more accurate, one-to-one correlations. These correlations would significantly further the development of HF ultrasound for real-time SLN evaluation. Citation Format: Khelfa S, Factor RE, Sanjinez DA, Zambrana AF, Doyle TE. Evaluation of sentinel lymph nodes with high-frequency ultrasound: Correlations to histopathology [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 PD2-05.

PurposeThe anticancer activity of valproic acid (VPA) is attributed to the inhibition of histone deacetylase. We previously published the genomically derived sensitivity signature for VPA (GDSS-VPA), a gene expression biomarker that predicts breast cancer sensitivity to VPA in vitro and in vivo. We conducted a window-of-opportunity study that examined the tolerability of VPA and the ability of the GDSS-VPA to predict biologic changes in breast tumors after treatment with VPA.Patients and MethodsEligible women had untreated breast cancer with breast tumors larger than 1.5 cm. After a biopsy, women were given VPA for 7 to 12 days, increasing from 30 mg/kg/d orally divided into two doses per day to a maximum of 50 mg/kg/d. After VPA treatment, serum VPA level was measured and then breast surgery or biopsy was performed. Tumor proliferation was assessed by using Ki-67 immunohistochemistry. Histone acetylation of peripheral blood mononuclear cells was assessed by Western blot. Dynamic contrast-enhanced magnetic resonance imaging scans were performed before and after VPA treatment.ResultsThirty women were evaluable. The median age was 54 years (range, 31-73 years). Fifty-two percent of women tolerated VPA at 50 mg/kg/d, but 10% missed more than two doses as a result of adverse events. Grade 3 adverse events included vomiting and diarrhea (one patient) and fatigue (one patient). The end serum VPA level correlated with a change in histone acetylation of peripheral blood mononuclear cells (ρ = 0.451; P = .024). Fifty percent of women (three of six) with triple-negative breast cancer had a Ki-67 reduction of at least 10% compared with 17% of other women. Women whose tumors had higher GDSS-VPA were more likely to have a Ki-67 decrease of at least 10% (area under the curve, 0.66).ConclusionVPA was well tolerated and there was a significant correlation between serum VPA levels and histone acetylation. VPA treatment caused a decrease in proliferation of breast tumors. The genomic biomarker correlated with decreased proliferation. Inhibition of histone deacetylase is a valid strategy for drug development in triple-negative breast cancer using gene expression biomarkers.

The 2013 American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) recommendations for HER2 testing contain a recommendation for pathologists with respect to invasive micropapillary carcinoma. The guidelines suggest that HER2 immunohistochemical staining that is intense but incomplete and would be considered 1+ may actually be HER2-amplified by fluorescence in situ hybridization. Thus, pathologists should consider reporting the immunohistochemistry as equivocal (2+) and employ an alternative testing methodology. This recommendation is based largely on one paper wherein the authors tested a series of 22 micropapillary carcinomas that were considered 1+ by immunohistochemistry and identified HER2 amplification in one case (5%). In order to assess for a possible discordance between HER2 immunohistochemistry and fluorescence in situ hybridization, we evaluated a series of invasive carcinomas with micropapillary features using both methodologies. As described by the WHO, invasive carcinomas with micropapillary features have small, hollow, or morula-like clusters of cells surrounded by clear stromal spaces. All cases had HER2 immunohistochemistry and fluorescence in situ hybridization performed, and for cases with equivocal fluorescence in situ hybridization results, an alternative Chromosome 17 probe (RAI1) was employed. All assays were scored according to the 2013 ASCO/CAP guidelines. Specifically for this study, immunohistochemistry was scored irrespective of the presence of micropapillary features. Overall, we identified HER2 amplification in 21 (47%) of the cases assayed, with the corresponding immunohistochemistry being 1+ (n=9), 2+ (n=11), and 3+ (n=1). The ASCO/CAP recommendation that this morphology may deviate from the typical staining pattern is highlighted, as we found that 43% of cases with micropapillary features and HER2 staining that would otherwise be scored as 1+ were HER2-amplified by fluorescence in situ hybridization. This study supports the ASCO/CAP recommendation that pathologists should consider reporting immunohistochemistry in this morphology as equivocal and perform reflex testing using in situ hybridization.

BACKGROUND: A decrease in Ki67 has been shown to be a predictor of response to tamoxifen. Previous trials have shown a decreased Ki67 proliferation index in breast tumors with as little as 2 weeks of preoperative tamoxifen. However, shortening the preoperative treatment time in window of opportunity studies increases patient acceptance for trial participation. The POWERPIINC trial examined the effect of 7 days of preoperative tamoxifen on breast tumor proliferation and patient symptoms. METHODS: Adult women with untreated stage I or II invasive breast cancer that was ER positive (>1%) planning on breast surgery with no contraindications to tamoxifen were enrolled. Women received 20mg of tamoxifen for 7 days up to the day of surgery and for 14 days afterwards. Proliferation was assessed by Ki67 immunohistochemistry before and after 7 days of tamoxifen. The proliferation genes from the PAM50 were also assessed by RT-PCR. Symptoms and QOL were assessed by the FACT-ES, MENQoL, and BMQ. RESULTS: 52 women were enrolled, and 44 were evaluable for Ki67. The median age was 58.5 years, and the median tumor diameter was 1.2cm. Most women (73%) were post-menopausal. Most tumors were PR positive (88%). Only 8% of tumors were HER2-positive. The Ki67 decreased by a geometric mean of 40% (95% CI 29%-63%), and 73% (95% CI 57%-85%) of women had tumors with decreased proliferation after 7 days of tamoxifen (p=0.0001 by paired t-test). No correlation was seen between the change in Ki-67 and change in FACT-ES or MENQoL scores. Women reported minimal to no bother from psychosocial or physical symptoms at baseline or on the day of surgery. Expression level of individual proliferation genes did not change after 7 days of tamoxifen. CONCLUSION: Seven days of tamoxifen showed a similar relative decrease in the Ki67 proliferation index as that reported for longer courses. Therefore, short window of opportunity trials can be informative. Citation Format: Cohen AL, Factor RE, Mooney K, Wade M, Serpico V, Salama M, Nelson E, Porretta J, Matsen C, Ostrander E, Bernard P, Boucher K, Neumayer L. PowerPIINC trial: Changes in tumor proliferation index and quality of life with 7 days of preoperative tamoxifen [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-10-05.

Background: Predicting the risk of relapse in patients with non-metastatic breast cancer is important for medical decisions and patient counseling. For patients who receive neoadjuvant chemotherapy, pathologic response and especially pathologic complete response (pCR) has been associated with risk of relapse; however this association is imperfect. Our prior work in patient-derived xenograft (PDX) models indicated that tumor engraftment in mice correlated with risk of recurrence. To understand further the prognostic utility of PDX, we designed a prospective clinical trial to determine the correlation between PDX generation with residual disease following neoadjuvant chemotherapy and relapse. Preliminary data are presented. Methods: Women with newly diagnosed non-metastatic hormone receptor low-positive (HR-low, ER and/or PR ≤ 10%) or negative breast cancer planned to receive systemic chemotherapy prior to definitive surgery were eligible. Tumor tissue at diagnosis was orthotopically implanted in NOD/SCID mice. The primary objective of the study is to correlate the ability of a tumor to engraft in mice with pathologic responses and clinical outcomes. Results: Between 12/2016 and 2/2020, 58 patients enrolled (triple negative breast cancer (TNBC), n=37; HR-low or negative/Her2+, n=11; or HR-low/Her2-, n=8; mixed, n=1). PDXs were successfully established from 16 patients. Patients uniformly received intensive preoperative chemotherapy per standard of care. Among the 12 patients whose tumors engrafted in mice (PDX(+)) and underwent surgery, the pCR rate was 41.7%. In the subgroup of patients with postoperative follow up >6 months (n=9), 3 patients had achieved a pCR, 1 of whom recurred; and 6 patients had residual disease, 3 of whom recurred (overall relapse rate 44.4%). All patients who relapsed (TNBC n=3; HR-low/Her2- n=1), experienced a very early relapse ( Among the 38 patients whose tumors did not engraft (PDX(-)) and underwent surgery, the overall pCR rate was 60.6%. In the subgroup of patients with postoperative follow up >6 months (n=30), 18 patients had achieved a pCR of whom none recurred, and 12 had residual disease of whom 1 patient (with TNBC) had locoregional recurrence 35.1 months after her definitive surgery (relapse rate 3.3%). She underwent repeat surgery followed by radiation therapy and 5.5 months after her recurrence, she remains disease-free. Achievement of pCR was not statistically different between the PDX(+) and PDX(-) group. In the entire cohort, the presence of residual disease was associated with high risk of relapse (22.2%) as compared to the achievement of pCR (4.8%, p = 0.16). However, successful tumor engraftment was associated not only with a higher risk of relapse (44.4% vs 3.3%, p = 0.0068, odds ratio 20.45), but also an early and exceptionally aggressive relapse. Conclusion. Our functional studies not only identify a patient population with a high risk of relapse with greater precision than the achievement of pCR, but also identify patients whose relapse has a particularly aggressive natural history. We established models that recapitulate this aggressive disease and in-depth genomic studies are underway. These studies will lead us to better patient stratification on the basis of risk of relapse and novel therapeutic strategies focused on patients with exceptionally aggressive breast cancers that our current diagnostic methods cannot identify. Citation Format: Christos Vaklavas, Zhengtao Chu, Rachel E Factor, Alana L Welm, Bryan E Welm, Cindy B Matsen. Towards personalized medicine - patient-derived breast tumor grafts as predictors of relapse and response to therapy. Preliminary results [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD7-01.

Approximately 40% of patients with stage I–III triple-negative breast cancer (TNBC) recur after standard treatment, whereas the remaining 60% experience long-term disease-free survival (DFS). There are currently no clinical tests to assess the risk of recurrence in TNBC patients. We previously determined that TNBC patients with MHC class II (MHCII) pathway expression in their tumors experienced significantly longer DFS. To translate this discovery into a clinical test, we developed an MHCII Immune Activation assay, which measures expression of 36 genes using NanoString technology. Preanalytical testing confirmed that the assay is accurate and reproducible in formalin-fixed paraffin-embedded (FFPE) tumor specimens. The assay measurements were concordant with RNA-seq, MHCII protein expression, and tumor-infiltrating lymphocyte counts. In a training set of 44 primary TNBC tumors, the MHCII Immune Activation Score was significantly associated with longer DFS (HR = 0.17; P = 0.015). In an independent validation cohort of 56 primary FFPE TNBC tumors, the Immune Activation Score was significantly associated with longer DFS (HR = 0.19; P = 0.011) independent of clinical stage. An Immune Activation Score threshold for identifying patients with very low risk of relapse in the training set provided 100% specificity in the validation cohort. The assay format enables adoption as a standardized clinical prognostic test for identifying TNBC patients with a low risk of recurrence. Correlative data support future studies to determine if the assay can identify patients in whom chemotherapy can be safely deescalated and patients likely to respond to immunotherapy. Significance: The MHCII Immune Activation assay identifies TNBC patients with a low risk of recurrence, addressing a critical need for prognostic biomarker tests that enable precision medicine for TNBC patients.

Objective: Rapid on-site evaluation (ROSE) has been shown to improve adequacy rates and reduce needle passes. ROSE is often performed by cytopathologists who have limited availability and may be costlier than alternatives. Several recent studies examined the use of alternative evaluators (AEs) for ROSE. A summary of this information could help inform guidelines regarding the use of AEs. The objective was to assess the accuracy of AEs compared to cytopathologists in assessing the adequacy of specimens during ROSE. Study Design: This was a systematic review and meta-analysis. Reporting and study quality were assessed using the STARD guidelines and QUADAS-2. All steps were performed independently by two evaluators. Summary estimates were obtained using the hierarchal method in Stata v14. Heterogeneity was evaluated using Higgins’ I2 statistic. Results: The systematic review identified 13 studies that were included in the meta-analysis. Summary estimates of sensitivity and specificity for AEs were 97% (95% CI: 92–99%) and 83% (95% CI: 68–92%). There was wide variation in accuracy statistics between studies (I2 = 0.99). Conclusions: AEs sometimes have accuracy that is close to cytopathologists. However, there is wide variability between studies, so it is not possible to provide a broad guideline regarding the use of AEs.

Objectives Telepathology enables histologic diagnosis to be made from a scanned slide visualized on a computer. Frozen sections (FSs) can be performed at remote locations and read by a pathologist at a central site. At our institution, qualifying breast cancer patients are enrolled in clinical trials that require FS on sentinel lymph nodes (SLNs) after neoadjuvant therapy (NAT), including chemotherapy or endocrine therapy. In this setting, histology is complicated by treatment effect and biopsy site changes. Others have reported good accuracy of FSs on SLNs after NAT. We investigated whether pathologists are accurate in diagnosing SLN FSs for such cases while using telepathology. To our knowledge, this has not been reported previously. Methods SLNs were entirely submitted and serially sectioned (2-mm thickness). At least two levels were cut. All FSs were submitted for formalin-fixed, paraffin-embedded permanent sections. A pathology assistant at the remote location prepared the FSs and scanned slides using the VisionTek M6 digital microscope ecosystem (East Dundee, IL). Cases were interpreted by board-certified pathologists who completed training on the VisionTek system. For this study, diagnoses from FSs and permanents were compared. Results Forty-five SLNs from 19 breast neoadjuvant cases were read by VisionTek from March 2017 to January 2019. Forty-three cases (96%) called negative by FSs were confirmed negative (on permanents). One hundred percent called positive by FSs were positive. Four SLN called atypical on FSs were positive. Three of these were neoadjuvant endocrine cases for invasive lobular carcinoma. Two cases called atypical were negative. One of these, called atypical/suspicious, resulted in axillary dissection. This case was reviewed by three pathologists at the time of surgery. It had abundant treatment effect, mimicking carcinoma. Conclusion While pitfalls exist, overall, the diagnostic accuracy of frozen section analysis by telepathology of SLNs from breast cases after neoadjuvant therapy is high.

SummaryInvasive lobular carcinoma (ILC) is the second most prevalent histologic subtype of invasive breast cancer. Here, we comprehensively profiled 817 breast tumors, including 127 ILC, 490 ductal (IDC), and 88 mixed IDC/ILC. Besides E-cadherin loss, the best known ILC genetic hallmark, we identified mutations targeting PTEN, TBX3, and FOXA1 as ILC enriched features. PTEN loss associated with increased AKT phosphorylation, which was highest in ILC among all breast cancer subtypes. Spatially clustered FOXA1 mutations correlated with increased FOXA1 expression and activity. Conversely, GATA3 mutations and high expression characterized luminal A IDC, suggesting differential modulation of ER activity in ILC and IDC. Proliferation and immune-related signatures determined three ILC transcriptional subtypes associated with survival differences. Mixed IDC/ILC cases were molecularly classified as ILC-like and IDC-like revealing no true hybrid features. This multidimensional molecular atlas sheds new light on the genetic bases of ILC and provides potential clinical options.

The tumor suppressor BRCA1 regulates the DNA damage response (DDR) and other processes that remain incompletely defined. Among these, BRCA1 heterodimerizes with BARD1 to ubiquitylate targets via its N-terminal E3 ligase activity. Here, it is demonstrated that BRCA1 promotes oxidative metabolism by degrading Oct1 (POU2F1), a transcription factor with proglycolytic and tumorigenic effects. BRCA1 E3 ubiquitin ligase mutation skews cells toward a glycolytic metabolic profile while elevating Oct1 protein. CRISPR-mediated Oct1 deletion reverts the glycolytic phenotype. RNA sequencing (RNAseq) confirms deregulation of metabolic genes downstream of Oct1. BRCA1 mediates Oct1 ubiquitylation and degradation, and mutation of two ubiquitylated Oct1 lysines insulates the protein against BRCA1-mediated destabilization. Oct1 deletion in MCF-7 breast cancer cells does not perturb growth in standard culture, but inhibits growth in soft agar and xenograft assays. In primary breast cancer clinical specimens, Oct1 protein levels correlate positively with tumor aggressiveness and inversely with BRCA1. These results identify BRCA1 as an Oct1 ubiquitin ligase that catalyzes Oct1 degradation to promote oxidative metabolism and restrict tumorigenicity. Mol Cancer Res; 16(3); 439–52. ©2018 AACR.

It is well-known that breast tumors exhibit different expression patterns that can be used to assign intrinsic subtypes – the PAM50 assay, for example, categorizes tumors into: Luminal A, Luminal B, HER2-enriched and Basal-like – yet tumors are often more complex than categorization can describe. We used 911 sporadic breast tumors to reparameterize expression from the PAM50 genes to five orthogonal tumor dimensions using principal components (PC). Three dimensions captured intrinsic subtype, two dimensions were novel, and all replicated in 945 TCGA tumors. By definition dimensions are independent, an important attribute for inclusion in downstream studies exploring effects of tumor diversity. One application where tumor subtyping has failed to provide impact is susceptibility genetics. Germline genetic heterogeneity reduces power for gene-finding. The identification of heritable tumor characteristics has potential to increase homogeneity. We compared 238 breast tumors from high-risk pedigrees not attributable to BRCA1 or BRCA2 to 911 sporadic breast tumors. Two PC dimensions were significantly enriched in the pedigrees (intrinsic subtypes were not). We performed proof-of-concept gene-mapping in one enriched pedigree and identified a 0.5 Mb genomewide significant region at 12q15 that segregated to the 8 breast cancer cases with the most extreme PC tumors through 32 meioses (p=2.6×10−8). In conclusion, our study: suggests a new approach to describe tumor diversity; supports the hypothesis that tumor characteristics are heritable providing new avenues for germline studies; and proposes a new breast cancer locus. Reparameterization of expression patterns may similarly inform other studies attempting to model the effects of tumor heterogeneity.

Context College of American Pathologists (CAP) and the American Society of Clinical Oncology have emphasized the need to reduce preanalytic variables for evaluating predictive biomarker expression in breast cancer. Postoperative x-ray of excised breast tissue is commonplace, yet is a variable that has not been investigated previously. We asked whether such radiation affects expression of relevant biomarkers. Design A previous study found that human breast cancers grown in mice demonstrate the same immunohistochemical and molecular profiles as the original tumors. Thirteen patient-derived xenografts were harvested fresh and divided for specimen radiography and a matched nonirradiated control, while following CAP/ASCO guidelines for cold ischemia time and fixation. Samples were processed in a tissue microarray for immunohistochemistry. Estrogen receptor (ER), progesterone receptor (PR), p53, and Ki67 staining was evaluated using an optimized scoring algorithm performed on digitally scanned slides. Samples were also scored manually by a blinded pathologist using the H-score method, and HER2 by the CAP/ASCO 2013 protocol. Histologic scores were compared by analysis of variance. Results There was no significant difference in quantity or intensity of staining between irradiated and nonirradiated samples for estrogen receptor (P=0.28), p53 (P=0.96), and Ki67 (P=0.94). A small but statistically significant difference was observed for PR (P=0.0058). HER2 staining was similarly unchanged in the 1 tumor exhibiting 3+ staining. Conclusions Our study demonstrates that x-ray of breast carcinomas does not significantly affect the expression of predictive biomarkers, with the exception of PR for unclear reasons. It also highlights the utility of the patient-derived xenograft model for biomarker studies.

Metastatic breast cancer remains challenging to treat, and most patients ultimately progress on therapy. This acquired drug resistance is largely due to drug-refractory sub-populations (subclones) within heterogeneous tumors. Here, we track the genetic and phenotypic subclonal evolution of four breast cancers through years of treatment to better understand how breast cancers become drug-resistant. Recurrently appearing post-chemotherapy mutations are rare. However, bulk and single-cell RNA sequencing reveal acquisition of malignant phenotypes after treatment, including enhanced mesenchymal and growth factor signaling, which may promote drug resistance, and decreased antigen presentation and TNF-α signaling, which may enable immune system avoidance. Some of these phenotypes pre-exist in pre-treatment subclones that become dominant after chemotherapy, indicating selection for resistance phenotypes. Post-chemotherapy cancer cells are effectively treated with drugs targeting acquired phenotypes. These findings highlight cancer’s ability to evolve phenotypically and suggest a phenotype-targeted treatment strategy that adapts to cancer as it evolves., In metastatic breast cancer, subclonal evolution can drive drug resistance. Here, the authors genetically and transcriptionally follow the evolution of four breast cancers over time and treatment, and suggest a phenotype-targeted treatment strategy to adapt to cancer as it evolves.

Context.—Statistical literacy can be defined as understanding the statistical tests and terminology needed for the design, analysis, and conclusions of original research or laboratory testing. Little is known about the statistical literacy of clinical or anatomic pathologists. Objective.—To determine the statistical methods most commonly used in pathology studies from the literature and to assess familiarity and knowledge level of these statistical tests by pathology residents and practicing pathologists. Design.—The most frequently used statistical methods were determined by a review of 1100 research articles published in 11 pathology journals during 2015. Familiarity with statistical methods was determined by a survey of pathology trainees and practicing pathologists at 9 academic institutions in which pathologists were asked to rate their knowledge of the methods identified by the focused review of the literature. Results.—We identified 18 statistical tests that appear frequently in published pathology studies. On average, pathologists reported a knowledge level between “no knowledge” and “basic knowledge” of most statistical tests. Knowledge of tests was higher for more frequently used tests. Greater statistical knowledge was associated with a focus on clinical pathology versus anatomic pathology, having had a statistics course, having an advanced degree other than an MD degree, and publishing research. Statistical knowledge was not associated with length of pathology practice. Conclusions.—An audit of pathology literature reveals that knowledge of about 12 statistical tests would be sufficient to provide statistical literacy for pathologists. On average, most pathologists report they can interpret commonly used tests but are unable to perform them. Most pathologists indicated that they would benefit from additional statistical training.

Objectives A decrease in Ki67 during neoadjuvant therapy predicts response to tamoxifen. Previous trials have shown a decreased Ki67 in breast tumors with as little as two or more weeks of preoperative tamoxifen. Shortening the preoperative treatment time in window of opportunity clinical trials makes these trials more attractive to women. POWERPIINC examined the effect of 7 days of preoperative tamoxifen on breast tumor proliferation and patient symptoms. Methods Women with untreated stage I/II, ER-positive, invasive breast cancer with no contraindications to tamoxifen were enrolled. Women received 20 mg of tamoxifen for 7 days up to the day of surgery. Proliferation was assessed by Ki67 immunohistochemistry before and after 7 days of tamoxifen. Symptoms and QOL were assessed by the FACT-ES and MENQOL. Adherence was measured by pill counts. Results 52 women were enrolled, and 44 were evaluable for Ki67. The median age was 58.5 years, and the median tumor diameter was 1.2 cm. Most women (73%) were post-menopausal. Most tumors were PR positive (88%) and HER2-negative (92%). The Ki67 decreased by a geometric mean of 40% (95% CI 29%–63%), and 73% (95% CI 57%–85%) of women had tumors with decreased proliferation (p = 0.0001 by paired t-test). Adherence to taking tamoxifen during the preoperative period was 100%. Women reported minimal bother from psychosocial or physical symptoms at baseline or on the day of surgery. Conclusion Seven days of tamoxifen showed a similar relative decrease in Ki67 as that reported for longer courses, was acceptable to women, and could be considered for window of opportunity studies.

The findings from genome-wide association studies hold enormous potential for novel insight into disease mechanisms. A major challenge in the field is to map these low-risk association signals to their underlying functional sequence variants (FSV). Simple sequence study designs are insufficient, as the vast numbers of statistically comparable variants and a limited knowledge of noncoding regulatory elements complicate prioritization. Furthermore, large sample sizes are typically required for adequate power to identify the initial association signals. One important question is whether similar sample sizes need to be sequenced to identify the FSVs. Here, we present a proof-of-principle example of an extreme discordant design to map FSVs within the 2q33 low-risk breast cancer locus. Our approach employed DNA sequencing of a small number of discordant haplotypes to efficiently identify candidate FSVs. Our results were consistent with those from a 2,000-fold larger, traditional imputation-based fine-mapping study. To prioritize further, we used expression-quantitative trait locus analysis of RNA sequencing from breast tissues, gene regulation annotations from the ENCODE consortium, and functional assays for differential enhancer activities. Notably, we implicate three regulatory variants at 2q33 that target CASP8 (rs3769823, rs3769821 in CASP8, and rs10197246 in ALS2CR12) as functionally relevant. We conclude that nested discordant haplotype sequencing is a promising approach to aid mapping of low-risk association loci. The ability to include more efficient sequencing designs into mapping efforts presents an opportunity for the field to capitalize on the potential of association loci and accelerate translation of association signals to their underlying FSVs. Cancer Res; 76(7); 1916–25. ©2016 AACR.

This is the protocol for a review and there is no abstract. The objectives are as follows: To determine the diagnostic accuracy of fine-needle aspiration and core-needle biopsy for the diagnosis of tumours (neoplastic versus non-neoplastic) in major salivary glands. To determine the diagnostic accuracy of fine-needle aspiration and core-needle biopsy for the diagnosis of malignant tumors in major salivary glands (i.e. the conditional probability that a lesion is malignant given that it is neoplastic). To identify factors that may affect the diagnostic accuracy of fine-needle aspiration for the diagnosis of major salivary gland lesions. There are many factors that could potentially affect the accuracy of the testing process. These include study-level factors (location, time period of study and setting: academic center versus community), disease spectrum (distribution of lesion types, distribution of glands), index test factors (too many to list), reference test factors and population factors (referral patterns, disease severity). While it is reasonable to suppose that any of these factors could affect FNAC test accuracy, there are few experimental data to guide the selection of factors for investigation. Also, in our experience, FNAC accuracy studies generally suffer from variable and incomplete reporting (Schmidt 2011; Schmidt 2011b). Thus, it is unlikely that studies would provide sufficient data to support an analysis of heterogeneity, even if a large number of studies were included. Thus, we do not expect that investigations of heterogeneity are likely to be feasible.

The use of high-frequency (HF) ultrasound (20-80 MHz) to determine tissue pathology is an inexpensive and real-time tool for differentiation of surgical margin specimens from breast conservation surgery (BCS). The development of this method as an intraoperative tool for BCS would greatly reduce the rate of re-excisions due to positive breast tissue margins. HF ultrasound was previously used in a 17-patient study to determine differences in breast tissue pathology of 34 surgical margins. Results from this pilot study demonstrated high accuracy, specificity, and sensitivity in the HF ultrasound data, and showed the immense potential of this method as a breast cancer detection tool. A large-scale validation study of this method was subsequently conducted using 349 margin specimens taken from 73 patients during BCS. Specimens ranged from 1-5 cm in length and width, 0.2-1.6 cm in thickness, and did not require any additional procedures or resection that affected the patient or surgical outcome. Each specimen was tested with HF ultrasound immediately following resection and then forwarded to pathology. Through-transmission data were collected from the specimens using two broadband, single-element transducers with a 50-MHz peak frequency (Olympus NDT, V358-SU), a HF square-wave pulser/receiver (UTEX, UT340), and a 1-GHz digital oscilloscope (Agilent, DSOX3104A). Peak density (the number of peaks and valleys in the 20-80 MHz frequency spectra range) and attenuation data were calculated from the ultrasonic spectra and waveforms, respectively. Peak density and attenuation correlate directly to tissue malignancy, and thresholds for these two parameters for differentiating benign vs. malignant tissue were determined using Fisher's Exact Test applied to the previously collected pilot study data. The peak density and attenuation results were then combined using a multivariate analysis. Since the ultrasonic measurements were collected on a per position basis (1-5 positions per margin), but the histopathology results were reported on a per specimen basis, the statistical measures for the ultrasonic results were calculated using two methods. First, the statistical measures were calculated based on a per position basis, where the pathology of each position was determined by the pathology results for the entire specimen. Second, the statistical measures were calculated based on a per specimen basis, where only one measurement position on each margin was selected (based on the highest peak density value) to correlate to the specimen pathology. The results of the first approach (per position basis) showed a sensitivity of 82.6%, a specificity of 72.3%, and an accuracy of 72.7%. The results of the second approach (per specimen basis) showed a sensitivity of 82.6%, a specificity of 61.7%, and an accuracy of 63.0%. The results of this study show potential for a rapid and inexpensive method of determining pathology of breast tissue surgical margins during BCS. This work was supported by funds from the Elsa U. Pardee Foundation, the Eppley Foundation for Research, the Western Alliance for Expanding Student Opportunities, theGovernor's Office of Economic Development of the State of Utah, the University of Utah, and Utah Valley University. Citation Format: Carter C, Neumayer LA, Factor RE, Doyle TE. Using high-frequency ultrasound (20-80 MHz) to differentiate malignant vs benign breast tissue in surgical margins [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 P6-03-10.

The originally published version of this Article contained an error in Figure 4. In panel a, grey boxes surrounding the subclones associated with patients #2 and #4 obscured adjacent portions of the heatmap. This error has now been corrected in both the PDF and HTML versions of the Article.

Numerous epidemiologic studies have reported associations between breastfeeding and breast cancer risk (1–9). Breastfeeding is hypothesized to decrease breast cancer risk by reducing a woman’s lifetime number of menstrual cycles, and thus her cumulative exposure to endogenous hormones (10), and increasing the differentiation of ductal cells, making them less susceptible to carcinogens (11). Additionally, breastfeeding may facilitate excretion of carcinogens via the milk ducts (12,13). History of breastfeeding could also have a beneficial effect on breast cancer prognosis and survival and might be an important prognostic factor to consider when evaluating a newly diagnosed patient. However, studies to date have reported mixed results for mortality (14–16), and to our knowledge no studies have examined recurrence. Breast cancer is a heterogeneous disease with distinct molecular subtypes that appear to have different risk factor profiles, require different treatment regimens, and have considerable variability in prognosis. For example, history and duration of breastfeeding have been found to be associated with decreased risk of triple-negative or basal-like breast cancer, although not with ER+ or luminal A breast cancer (2,4,6,7,9,17). Recently, the PAM50 gene expression assay has been used to subtype breast tumors into luminal A, luminal B, human epidermal growth factor receptor 2 (HER2)–enriched, basal-like, and normal-like intrinsic subtypes (18). The assay has been shown to add valuable clinical information beyond standard clinical and pathological factors (estrogen receptor [ER], progesterone receptor [PR], HER2) used for risk assessment and therapy decision-making in breast cancer (19,20). Our study aims were to examine the associations of lifetime breastfeeding with breast cancer intrinsic subtype, as defined by the PAM50 assay, and the associations of lifetime breastfeeding with breast cancer recurrence and mortality overall and by subtype.

Children in sub-Saharan Africa continue to acquire and die from cerebral malaria, despite efforts to control or eliminate the causative agent, Plasmodium falciparum. We present a quantitative histopathological assessment of the sequestration of parasitized erythrocytes in multiple organs obtained during a prospective series of 103 autopsies performed between 1996 and 2010 in Blantyre, Malawi, on pediatric patients who died from cerebral malaria and controls. After the brain, sequestration of parasites was most intense in the gastrointestinal tract, both in patients with cerebral malaria and those with parasitemia in other organs. Within cases of histologically defined cerebral malaria, which includes phenotypes termed "sequestration only" (CM1) and "sequestration with extravascular pathology" (CM2), CM1 was associated with large parasite numbers in the spleen and CM2 with intense parasite sequestration in the skin. A striking histological finding overall was the marked sequestration of parasitized erythrocytes across most organs in patients with fatal cerebral malaria, supporting the hypothesis that the disease is, in part, a result of a high level of total-body parasite sequestration.

Background Invasive breast cancers are now commonly classified using gene expression into biologically and clinically distinct tumor subtypes. However, the role of obesity in breast tumor gene expression and intrinsic subtype is unknown. Methods Early-stage breast cancer (BC) patients (n = 1,676) were sampled from two prospective cohorts. The PAM50 qRT-PCR assay was used to: a) assess tumor gene expression levels for ESR1, PGR, ERBB2, and 10 proliferation genes and b) classify tumors into intrinsic subtype (Luminal A, Luminal B, Basal-like, HER2-enriched, Normal-like). Body mass index (BMI) around BC diagnosis (kg/m2) was categorized as: underweight (