The impact of histologic subtype on primary site surgery in the management of metastatic lobular versus ductal breast cancer: a population based study from the National Cancer Database (NCDB).

PURPOSE: Primary site surgery for metastatic breast cancer improves local control but does not impact overall survival. Whether histologic subtype influences patient selection for surgery is unknown. Given differences in surgical management between early-stage lobular versus ductal disease, we evaluated the impact of histology on primary site surgery in patients with metastatic breast cancer. METHODS: The National Cancer Database (NCDB, 2010-2016) was queried for patients with stage IV HR-positive, HER2-negative invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC). We compared clinicopathologic features, primary site surgery rates, and outcomes by histologic subtype. Multivariable Cox proportional hazard models with and without propensity score matching were used for overall survival (OS) analyses. RESULTS: In 25,294 patients, primary site surgery was slightly but significantly less common in the 6,123 patients with ILC compared to the 19,171 patients with IDC (26.9% versus 28.8%, p = 0.004). Those with ILC were less likely to receive chemotherapy (41.3% versus 47.4%, p < 0.0001) or radiotherapy (29.1% versus 37.9%, p < 0.0001), and had shorter OS. While mastectomy rates were similar, those with ILC who underwent lumpectomy had significantly higher positive margin rates (ILC 15.7% versus IDC 11.2%, p = 0.025). In both groups, the odds of undergoing surgery decreased over time, and were higher in younger patients with T2/T3 tumors and higher nodal burden. CONCLUSION: Lobular histology is associated with less primary site surgery, higher positive margin rates, less radiotherapy and chemotherapy, and shorter OS compared to those with HR-positive HER2-negative IDC. These findings support the need for ILC-specific data and treatment approaches in the setting of metastatic disease.

Menstrual Phase and Menopausal Status Classification of Benign Breast Tissue Using Hormone-Regulated Gene Expression and Histomorphology: A Validation Study.

BACKGROUND: The validation of breast cancer risk biomarkers in benign breast samples (BBS) is a long-sought goal, hampered by the fluctuation of gene and protein expression with menstrual phase (MP) and menopausal status (MS). Previously, we identified hormone-related gene expression and histomorphology parameters to classify BBS by MS/MP. We now evaluate both together, to validate our prior results. PATIENTS AND METHODS: BBS were obtained from consenting women (86 premenopausal, 55 postmenopausal) undergoing reduction mammoplasty (RM) or contralateral unaffected breast (CUB) mastectomy. MP/MS was defined using classical criteria for menstrual dates and hormone levels on the day of surgery. BBS gene expression was measured with reverse transcription quantitative polymerase chain reaction (RT-qPCR) for three luteal phase (LP) genes (TNFSF11, DIO2, MYBPC1) and four menopausal genes (PGR, GREB1, TIFF1, CCND1). Premenopausal samples were classified into LP or non-LP, using published histomorphology parameters. Logistic regression and receiver-operator curve analysis was performed to assess area under the curve (AUC) for prediction of MP/MS. RESULTS: In all 131 women, menopausal genes plus age > 50 years predicted true MS [AUC 0.93, 95% confidence interval (CI) 0.89, 0.97]. Among premenopausal women, high TNFSF11 expression distinguished non-LP from LP samples (AUC 0.80, 95% CI 0.70, 0.91); the addition of histomorphology improved the prediction nonsignificantly (AUC 0.87, 95% CI 0.78, 0.96). In premenopausal subsets, addition of histomorphology improved LP prediction in RM (AUC 0.95, 95% CI 0.87, 1.0), but not in CUB (0.84, 95% CI 0.72, 0.96). CONCLUSIONS: Expression of five-gene set accurately predicts menopausal status and menstrual phase in BBS, facilitating the development of breast cancer risk biomarkers using large, archived sample repositories.

Using ecological momentary assessment to understand associations between daily physical activity and symptoms in breast cancer patients undergoing chemotherapy.

PURPOSE: Understanding real-time relationships between physical activity (PA) and symptoms during chemotherapy (CT) could have important implications for intervention. This study used ecological momentary assessment to examine the relationship between objective PA and symptoms during CT. METHODS: Breast cancers patients (n = 67; Mage = 48.6 (SD = 10.3)) participated in data collection at three time points during CT: beginning, middle, and end. At each time point, participants answered four prompts assessing symptoms and wore an accelerometer for 10 days (3 days pre-CT, day of CT, and 6 days post-CT). Multilevel linear regression models examined the between- and within-person associations between moderate to vigorous (MVPA) and light-intensity physical activity (LPA) and same and next-day symptom ratings controlling for covariates. RESULTS: On days when individuals engaged in more LPA or MVPA, separately, they reported improved affect, anxiety, fatigue, physical functioning (walking and activities of daily living), pain, and cognition that day (p < 0.001 for all). Findings were consistent for next-day symptom ratings with the exception that only previous day LPA was related to next-day fatigue and neither LPA nor MVPA were related to next-day cognition (p < 0.001 for all). No between-person effects were found. CONCLUSIONS: Within person higher than usual PA on a given day, regardless of intensity, is associated with improved symptoms ratings on the current and next day. IMPLICATIONS FOR CANCER SURVIVORS: Encouraging breast cancer patients undergoing CT to engage in daily PA could help manage CT-associated symptoms.

Deep learning for cancer type classification and driver gene identification.

BACKGROUND: Genetic information is becoming more readily available and is increasingly being used to predict patient cancer types as well as their subtypes. Most classification methods thus far utilize somatic mutations as independent features for classification and are limited by study power. We aim to develop a novel method to effectively explore the landscape of genetic variants, including germline variants, and small insertions and deletions for cancer type prediction. RESULTS: We proposed DeepCues, a deep learning model that utilizes convolutional neural networks to unbiasedly derive features from raw cancer DNA sequencing data for disease classification and relevant gene discovery. Using raw whole-exome sequencing as features, germline variants and somatic mutations, including insertions and deletions, were interactively amalgamated for feature generation and cancer prediction. We applied DeepCues to a dataset from TCGA to classify seven different types of major cancers and obtained an overall accuracy of 77.6%. We compared DeepCues to conventional methods and demonstrated a significant overall improvement (p < 0.001). Strikingly, using DeepCues, the top 20 breast cancer relevant genes we have identified, had a 40% overlap with the top 20 known breast cancer driver genes. CONCLUSION: Our results support DeepCues as a novel method to improve the representational resolution of DNA sequencings and its power in deriving features from raw sequences for cancer type prediction, as well as discovering new cancer relevant genes.

Progesterone receptor antagonists reverse stem cell expansion and the paracrine effectors of progesterone action in the mouse mammary gland.

BACKGROUND: The ovarian hormones estrogen and progesterone (EP) are implicated in breast cancer causation. A specific consequence of progesterone exposure is the expansion of the mammary stem cell (MSC) and luminal progenitor (LP) compartments. We hypothesized that this effect, and its molecular facilitators, could be abrogated by progesterone receptor (PR) antagonists administered in a mouse model. METHODS: Ovariectomized FVB mice were randomized to 14 days of treatment: sham, EP, EP + telapristone (EP + TPA), EP + mifepristone (EP + MFP). Mice were then sacrificed, mammary glands harvested, and mammary epithelial cell lineages separated by flow cytometry using cell surface markers. RNA from each lineage was sequenced and differential gene expression was analyzed using DESeq. Quantitative PCR was performed to confirm the candidate genes discovered in RNA seq. ANOVA with Tukey post hoc analysis was performed to compare relative expression. Alternative splicing events were examined using the rMATs multivariate analysis tool. RESULTS: Significant increases in the MSC and luminal mature (LM) cell fractions were observed following EP treatment compared to control (p < 0.01 and p < 0.05, respectively), whereas the LP fraction was significantly reduced (p < 0.05). These hormone-induced effects were reversed upon exposure to TPA and MFP (p < 0.01 for both). Gene Ontology analysis of RNA-sequencing data showed EP-induced enrichment of several pathways, with the largest effect on Wnt signaling in MSC, significantly repressed by PR inhibitors. In LP cells, significant induction of Wnt4 and Rankl, and Wnt pathway intermediates Lrp2 and Axin2 (confirmed by qRTPCR) were reversed by TPA and MFP (p < 0.0001). Downstream signaling intermediates of these pathways (Lrp5, Mmp7) showed similar effects. Expression of markers of epithelial-mesenchymal transition (Cdh1, Cdh3) and the induction of EMT regulators (Zeb1, Zeb2, Gli3, Snai1, and Ptch2) were significantly responsive to progesterone. EP treatment was associated with large-scale alternative splicing events, with an enrichment of motifs associated with Srsf, Esrp, and Rbfox families. Exon skipping was observed in Cdh1, Enah, and Brd4. CONCLUSIONS: PR inhibition reverses known tumorigenic pathways in the mammary gland and suppresses a previously unknown effect of progesterone on RNA splicing events. In total, our results strengthen the case for reconsideration of PR inhibitors for breast cancer prevention.

Preoperative Breast MRI for Newly Diagnosed Ductal Carcinoma in Situ: Imaging Features and Performance in a Multicenter Setting (ECOG-ACRIN E4112 Trial).

Background There are limited data from clinical trials describing preoperative MRI features and performance in the evaluation of mammographically detected ductal carcinoma in situ (DCIS). Purpose To report qualitative MRI features of DCIS, MRI performance in the identification of additional disease, and associations of imaging features with pathologic, genomic, and surgical outcomes from the Eastern Cooperative Oncology Group-American College of Radiology Imaging Network (ECOG-ACRIN) E4112 trial. Materials and Methods Secondary analyses of a multicenter prospective clinical trial from the ECOG-ACRIN Cancer Research Group included women with DCIS diagnosed with conventional imaging techniques (mammography and US), confirmed via core-needle biopsy (CNB), and enrolled between March 2015 and April 2016 who were candidates for wide local excision (WLE) based on conventional imaging and clinical examination results. DCIS MRI features and pathologic features from CNB and excision were recorded. Each woman without invasive upgrade of the index DCIS at WLE received a 12-gene DCIS score. MRI performance metrics were calculated. Associations of imaging features with invasive upgrade, dichotomized DCIS score (<39 vs ≥39), and single WLE success were estimated in uni- and multivariable analyses. Results Among 339 women (median age, 60 years; interquartile range, 51-66 years), most DCIS cases showed nonmass enhancement (NME) (195 of 339 [58%]) on MRI scans with larger median size than on mammograms (19 mm vs 12 mm; P < .001). Positive predictive value of MRI-prompted CNBs was 32% (21 of 66) (95% CI: 22, 44), yielding an additional cancer detection rate of 6.2% (21 of 339) (95% CI: 4.1, 9.3). MRI false-positive rate was 14.2% (45 of 318) (95% CI: 10.7, 18.4). No imaging features were associated with invasive upgrade or DCIS score (P = .05 to P = .95). Smaller size and focal NME distribution at MRI were linked to single WLE success (P < .001). Conclusion Preoperative MRI depicted ductal carcinoma in situ (DCIS) diagnosed with conventional imaging most commonly as nonmass enhancement, with larger median span than mammography, and additional cancer detection rate of 6.2%. MRI features of this subset of DCIS did not enable prediction of pathologic or genomic outcomes. Clinical trial registration no. NCT02352883 © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Kuhl in this issue. An earlier incorrect version of this article appeared online. This article was corrected on August 4, 2021.

High-Resolution Full-3D Specimen Imaging for Lumpectomy Margin Assessment in Breast Cancer.

BACKGROUND: Two-dimensional (2D) specimen radiography (SR) and tomosynthesis (DBT) for breast cancer yield data that lack high-depth resolution. A volumetric specimen imager (VSI) was developed to provide full-3D and thin-slice cross-sectional visualization at a 360° view angle. The purpose of this prospective trial was to compare VSI, 2D SR, and DBT interpretation of lumpectomy margin status with the final pathologic margin status of breast lumpectomy specimens. METHODS: The study enrolled 200 cases from two institutions. After standard imaging and interpretation was performed, the main lumpectomy specimen was imaged with the VSI device. Image interpretation was performed by three radiologists after surgery based on VSI, 2D SR, and DBT. A receiver operating characteristic (ROC) curve was created for each method. The area under the curve (AUC) was computed to characterize the performance of the imaging method interpreted by each user. RESULTS: From 200 lesions, 1200 margins were interpreted. The AUC values of VSI for the three radiologists were respectively 0.91, 0.90, and 0.94, showing relative improvement over the AUCs of 2D SR by 54%, 13%, and 40% and DBT by 32% and 11%, respectively. The VSI has sensitivity ranging from 91 to 94%, specificity ranging from 81 to 85%, a positive predictive value ranging from 25 to 30%, and a negative predicative value of 99%. CONCLUSIONS: The ROC curves of the VSI were higher than those of the other specimen imaging methods. Full-3D specimen imaging can improve the correlation between the main lumpectomy specimen margin status and surgical pathology. The findings from this study suggest that using the VSI device for intraoperative margin assessment could further reduce the re-excision rates for women with malignant disease.

Breast cancer risk assessment and management programs: A practical guide.

Breast cancer risk assessment continues to evolve as emerging knowledge of breast cancer risk drivers and modifiers enables better identification of high-risk women who may benefit from increased screening or targeted risk-reduction protocols. The ongoing development of breast cancer Risk Assessment and Management Programs (RAMPs) presents an opportunity to decrease breast cancer disease incidence with evidence-based interventions. The goal of this review was to provide a practical guide for providers seeking to establish or update a breast cancer risk assessment and management program. We outline genetic/familial, personal, reproductive, and lifestyle-related factors while discussing the incorporation of risk modeling for precise risk estimate personalization. We further describe the process for determining a risk management plan: information gathering, generation of a risk profile, and articulation and implementation of risk reduction. We also include an overview of clinical workflows in breast cancer management programs and underlines the logistics of establishing a program as well as general principles for guiding the formulation of an individualized risk management plan. We discuss practical considerations, such as clinic structure and operation, allocation of resources, and patient education. Other critical aspects of program design, including identification of the target population, delineation of the core components of the clinical experience, definition of provider roles, description of referral mechanisms, and the launching of a marketing plan are also addressed. The process of risk assessment is both anxiety-provoking and empowering for women at increased risk. New knowledge has enabled strategies to both understand the risk and control it through evidence-based risk management. These benefits can now be realized by an increasing number of unaffected, high-risk patients collaborating with risk management practitioners. Continuation of these efforts will lead to further progress in both risk stratification and risk management of women at elevated breast cancer risk in the near future.

BRCA1 mutation influences progesterone response in human benign mammary organoids.

BACKGROUND: Women, who carry a germline BRCA1 gene mutation, have a markedly increased risk of developing breast cancer during their lifetime. While BRCA1 carriers frequently develop triple-negative, basal-like, aggressive breast tumors, hormone signaling is important in the genesis of BRCA1 mutant breast cancers. We investigated the hormone response in BRCA1-mutated benign breast tissue using an in vitro organoid system. METHODS: Scaffold-free, multicellular human breast organoids generated from benign breast tissues from non-carrier or BRCA1 mutation carriers were treated in vitro with a stepwise menstrual cycle hormone regimen of estradiol (E2) and progesterone (P4) over the course of 28 days. RESULTS: Breast organoids exhibited characteristics of the native breast tissue, including expression of hormone receptors, collagen production, and markers of luminal and basal epithelium, and stromal fibroblasts. RNA sequencing analysis revealed distinct gene expression in response to hormone treatment in the non-carrier and BRCA1-mutated organoids. The selective progesterone receptor modulator, telapristone acetate (TPA), was used to identify specifically PR regulated genes. Specifically, extracellular matrix organization genes were regulated by E2+P4+TPA in the BRCA1-mutated organoids but not in the non-carrier organoids. In contrast, in the non-carrier organoids, known PR target genes such as the cell cycle genes were inhibited by TPA. CONCLUSIONS: These data show that BRCA1 mutation influences hormone response and in particular PR activity which differs from that of non-carrier organoids. Our organoid model system revealed important insights into the role of PR in BRCA1-mutated benign breast cells and the critical paracrine actions that modify hormone receptor (HR)-negative cells. Further analysis of the molecular mechanism of BRCA1 and PR crosstalk is warranted using this model system.

What does risk of future cancer mean to breast cancer patients?

PURPOSE: Newly diagnosed breast cancer patients greatly overestimate their risk of developing contralateral breast cancer (CBC). Better understanding of patient conceptions of risk would facilitate doctor-patient communication and surgical decision making. In this mixed methods study, we prospectively examined breast cancer patients' perceived risk of future cancer and the reported factors that drove their risk perceptions. METHODS: Women age 21-60 diagnosed with breast cancer without a BRCA mutation or known distant metastases completed a study interview between surgical consult and surgical treatment. Participants completed a 12-item Perceived Risk Questionnaire, which assessed 10-year and lifetime risks of ipsilateral local recurrence, CBC, and distant recurrence. Patients provided qualitative explanations for their answers. RESULTS: Sixty-three patients completed study interviews (mean age 50.3). Participants were primarily White (85.7%) and 90.5% had attended college. Patients estimated their 10-year risk of CBC as 22.0%, nearly 4 times the established 10-year risk. Women attributed their risk perceptions to "gut feelings" about future cancer, even when women knew those feelings contradicted medically established risk. Perceptions of risk also reflected beliefs that cancer is random and that risk for local recurrence, CBC, and distant recurrence are the same. CONCLUSIONS: Our findings point to the need for novel ways of presenting factual information regarding both risk of recurrence and of new primary cancers, as well as the necessity of acknowledging cognitive and affective processes many patients use when conceptualizing risk. By differentiating women's intuitive feelings about risk from their knowledge of medically estimated risk, doctors can enhance informed decision making.

Cancer classification and pathway discovery using non-negative matrix factorization.

OBJECTIVES: Extracting genetic information from a full range of sequencing data is important for understanding disease. We propose a novel method to effectively explore the landscape of genetic mutations and aggregate them to predict cancer type. DESIGN: We applied non-smooth non-negative matrix factorization (nsNMF) and support vector machine (SVM) to utilize the full range of sequencing data, aiming to better aggregate genetic mutations and improve their power to predict disease type. More specifically, we introduce a novel classifier to distinguish cancer types using somatic mutations obtained from whole-exome sequencing data. Mutations were identified from multiple cancers and scored using SIFT, PP2, and CADD, and collapsed at the individual gene level. nsNMF was then applied to reduce dimensionality and obtain coefficient and basis matrices. A feature matrix was derived from the obtained matrices to train a classifier for cancer type classification with the SVM model. RESULTS: We have demonstrated that the classifier was able to distinguish four cancer types with reasonable accuracy. In five-fold cross-validations using mutation counts as features, the average prediction accuracy was 80% (SEM = 0.1%), significantly outperforming baselines and outperforming models using mutation scores as features. CONCLUSION: Using the factor matrices derived from the nsNMF, we identified multiple genes and pathways that are significantly associated with each cancer type. This study presents a generic and complete pipeline to study the associations between somatic mutations and cancers. The proposed method can be adapted to other studies for disease status classification and pathway discovery.

Feasibility and acceptability of intensive longitudinal data collection of activity and patient-reported outcomes during chemotherapy for breast cancer.

PURPOSE: Ecological momentary assessment (EMA) may help us better understand biopsychosocial determinants and outcomes of physical activity during chemotherapy, but may be burdensome for patients. The purpose of this study was to determine the feasibility and acceptability of using EMA to assess activity, symptoms, and motivation among early-stage breast cancer patients undergoing chemotherapy. METHODS: Women were instructed to wear an accelerometer 24/7 (hip during day and wrist overnight). Text message prompts were sent 4 times/day concerning patient-reported symptoms and motivational factors for 10 consecutive days (3 days pre-, day of, and 6 days post-chemotherapy dose). These measures occurred at the beginning, middle, and end of a full course of chemotherapy. At study conclusion, participants reported on perceived study acceptability, burden, and reactivity. RESULTS: Of the 75 women who consented to participate, 63 (84%) completed all 3 assessment time points. Participants responded to 86% of total text prompts and had valid accelerometer data on 82% of study days. Compliance was similar across all time points. The majority (78%) rated their study experience as positive; 100% were confident in their ability to use study technology. Reactivity varied with 27% indicating answering symptom questions did not affect how they felt and 44% and 68% indicated answering questions and wearing the accelerometer, respectively, made them want to increase activity. CONCLUSIONS: Findings indicate EMA methods are feasible for breast cancer patients undergoing chemotherapy. EMA may help us better understand the biopsychosocial processes underlying breast cancer patients' activity in the context of daily life.

Clinical Trials for Ductal Carcinoma In Situ of the Breast.

Ductal carcinoma in situ (DCIS) of the breast is a non-obligatory precursor to invasive breast carcinoma, with a variable natural history and biological potential for progression to invasive disease. Over the past 30 years, clinical trials have applied the therapeutic principles used for invasive carcinoma to treat DCIS (surgery, with or without breast radiotherapy, and post-operative endocrine therapy), with excellent survival outcomes, and in-breast recurrence rates that range from 0.5 to 1% annually. However, half of such recurrences are again in-situ lesions, and intensive therapy is likely not necessary for all patients. Current clinical research is focused on a better characterization of the potential of individual lesions to progress to invasive disease, and to identify women who would do well with lesser treatment. Three ongoing trials in the United States and Europe randomize women to active surveillance (with or without endocrine therapy) versus usual treatment with surgery and radiotherapy. The use of pre-operative endocrine therapy has been evaluated in a recently completed trial of letrozole use in postmenopausal women with DCIS; and in on-going trials of tamoxifen, used either orally, or as a 4-hydroxytamoxifen gel formulation for application to the breast skin. This review summaries the major past and current clinical trials of DCIS, and the likely trajectories of DCIS management in the near future.

Using natural language processing and machine learning to identify breast cancer local recurrence.

BACKGROUND: Identifying local recurrences in breast cancer from patient data sets is important for clinical research and practice. Developing a model using natural language processing and machine learning to identify local recurrences in breast cancer patients can reduce the time-consuming work of a manual chart review. METHODS: We design a novel concept-based filter and a prediction model to detect local recurrences using EHRs. In the training dataset, we manually review a development corpus of 50 progress notes and extract partial sentences that indicate breast cancer local recurrence. We process these partial sentences to obtain a set of Unified Medical Language System (UMLS) concepts using MetaMap, and we call it positive concept set. We apply MetaMap on patients' progress notes and retain only the concepts that fall within the positive concept set. These features combined with the number of pathology reports recorded for each patient are used to train a support vector machine to identify local recurrences. RESULTS: We compared our model with three baseline classifiers using either full MetaMap concepts, filtered MetaMap concepts, or bag of words. Our model achieved the best AUC (0.93 in cross-validation, 0.87 in held-out testing). CONCLUSIONS: Compared to a labor-intensive chart review, our model provides an automated way to identify breast cancer local recurrences. We expect that by minimally adapting the positive concept set, this study has the potential to be replicated at other institutions with a moderately sized training dataset.

Development of a nomogram to predict the clinical impact of a postexcision preirradiation mammogram.

We aimed to better quantify the impact of a postexcision preirradiation mammogram (PPM), first by identifying factors associated with abnormal results and then incorporating these findings into a nomogram. Beginning February 2011, our institution made a practice change to obtain a PPM on all patients with any calcifications identified. A total of 530 patients underwent a PPM. Suspicious abnormalities were reported in 61 patients (11.5%), with the PPM leading to a change in management in 47 instances (8.9%). A nomogram was created based on patient and tumor characteristics to identify patients most likely to have an abnormal PPM.

Changing local therapy in breast cancer: who needs what, and when?

The local therapy of breast cancer continues to evolve toward less surgery. Breast conservation is firmly in place, with recent trends toward decreased rates of re-excision. Axillary dissection is becoming a rare operation and is being replaced by sentinel node biopsy. The switch to sentinel node biopsy occurred first in patients with pathologically tumor-free nodes, and later in patients with limited nodal disease. Sentinel node biopsy is now also widely used in patients with pathologically positive nodes who receive neoadjuvant chemotherapy. Axillary surgery is being replaced with radiotherapy in some situations, and ongoing trials will further clarify the need for nodal radiotherapy in specific situations following neoadjuvant systemic therapy. Shorter radiotherapy regimens are widely accepted as the standard of care following breast conservation, and the omission of radiotherapy is recognized as appropriate for older patients. The appropriate sequencing of specific components of local therapy, particularly with regard to the timing of chemotherapy, requires thoughtful multidisciplinary planning and leveraging of the strengths of each component of therapy. Here, we review issues related to therapeutic sequencing and decision making in the local therapy of breast cancer.

Overexpression of lipid metabolism genes and PBX1 in the contralateral breasts of women with estrogen receptor-negative breast cancer.

Risk biomarkers for estrogen receptor (ER)-negative breast cancer have clear value for breast cancer prevention. We previously reported a set of lipid metabolism (LiMe) genes with high expression in the contralateral unaffected breasts (CUBs) of ER-negative cancer cases. We now further examine LiMe gene expression in both tumor and CUB, and investigate the role of Pre-B-cell leukemia homeobox-1 (PBX1) as a candidate common transcription factor for LiMe gene expression. mRNA was extracted from laser-capture microdissected epithelium from tumor and CUB of 84 subjects (28 ER-positive cases, 28 ER-negative cases, 28 healthy controls). Gene expression was quantitated by qRT-PCR. Logistic regression models were generated to predict ER status of the contralateral cancer. Protein expression of HMGCS2 and PBX1 was measured using immunohistochemistry. The effect of PBX1 on LiMe gene expression was examined by overexpressing PBX1 in MCF10A cells with or without ER, and by suppressing PBX1 in MDA-MB-453 cells. The expression of DHRS2, HMGCS2, UGT2B7, UGT2B11, ALOX15B, HPGD, UGT2B28 and GLYATL1 was significantly higher in ER-negative versus ER-positive CUBs, and predicted ER status of the tumor in test and validation sets. In contrast, LiMe gene expression was significantly lower in ER-negative than ER-positive tumors. PBX1 overexpression in MCF10A cells up-regulated most LiMe genes, but not in MCF10A cells overexpressing ER. Suppressing PBX1 in MDA-MB-453 cells resulted in decrease of LiMe gene expression. Four binding sites of PBX1 and cofactor were identified in three lipid metabolism genes using ChIP-qPCR. These data suggest a novel role for PBX1 in the regulation of lipid metabolism genes in benign breast, which may contribute to ER-negative tumorigenesis.

Risk Factors Leading to Complications in Early-Stage Breast Cancer Following Breast-Conserving Surgery and Intraoperative Radiotherapy.

OBJECTIVE: The aim of this study was to evaluate outcomes after breast-conserving surgery (BCS) and intraoperative radiotherapy (IORT), and to identify risk factors associated with complications. MATERIALS/METHODS: We evaluated patients with early-stage breast cancer treated from January 1, 2011 to January 31, 2014 with BCS and IORT at a single institution. The presence of breast cancer recurrences, complications, or fat necrosis were assessed at subsequent follow-up visits using physical examination and breast imaging. RESULTS: Overall, 113 patients, of whom three were undergoing bilateral treatments, were identified. The median length of time for IORT was 29 min and 36 s (range 15:50-59:00). Fifteen patients received additional external beam radiotherapy (EBRT), and the median follow-up was 40.3 months (range 1.6-58.3) for all patients. To date, one biopsy-proven ipsilateral recurrence has been noted (0.9%), for which the patient elected to undergo a mastectomy. Nine patients were found to have wound complications (7.7%) and two had fat necrosis (1.7%) on follow-up. Of all the evaluated risk factors, only applicator size (p < 0.01) had a statistically significant association with an increase in complications. CONCLUSIONS: With a short follow-up, IORT appears to be a safe treatment modality for a select group of patients, leading to a reasonable increase in operating room time and complication rates following BCS. The utilization of larger applicators at the time of IORT was associated with an increase in wound complications and fat necrosis.