Clinicopathological Predictors of Positive Resection Margins in Breast-Conserving Surgery.

BACKGROUND: Ductal carcinoma in situ (DCIS) is associated with risk of positive resection margins following breast-conserving surgery (BCS) and subsequent reoperation. Prior reports grossly underestimate the risk of margin positivity with IBC containing a DCIS component (IBC + DCIS) due to patient-level rather than margin-level analysis. OBJECTIVE: The aim of this study was to delineate the relative risk of IBC + DCIS compared with pure IBC (without a DCIS component) on margin positivity through detailed margin-level interrogation. METHODS: A single institution, retrospective, observational cohort study was conducted in which pathology databases were evaluated to identify patients who underwent BCS over 5 years (2014-2019). Margin-level interrogation included granular detail into the extent, pathological subtype and grade of disease at each resection margin. Predictors of a positive margin were computed using multivariate regression analysis. RESULTS: Clinicopathological details were examined from 5454 margins from 909 women. The relative risk of a positive margin with IBC + DCIS versus pure IBC was 8.76 (95% confidence interval [CI] 6.64-11.56) applying UK Association of Breast Surgery guidelines, and 8.44 (95% CI 6.57-10.84) applying the Society of Surgical Oncology/American Society for Radiation Oncology guidelines. Independent predictors of margin positivity included younger patient age (0.033, 95% CI 0.006-0.060), lower specimen weight (0.045, 95% CI 0.020-0.069), multifocality (0.256, 95% CI 0.137-0.376), lymphovascular invasion (0.138, 95% CI 0.068-0.208) and comedonecrosis (0.113, 95% CI 0.040-0.185). CONCLUSIONS: Compared with pure IBC, the relative risk of a positive margin with IBC + DCIS is approximately ninefold, significantly higher than prior estimates. This margin-level methodology is believed to represent the impact of DCIS more accurately on margin positivity in IBC.

Primary radiotherapy and deep inferior epigastric perforator flap reconstruction for patients with breast cancer (PRADA): a multicentre, prospective, non-randomised, feasibility study.

BACKGROUND: Radiotherapy before mastectomy and autologous free-flap breast reconstruction can avoid adverse radiation effects on healthy donor tissues and delays to adjuvant radiotherapy. However, evidence for this treatment sequence is sparse. We aimed to explore the feasibility of preoperative radiotherapy followed by skin-sparing mastectomy and deep inferior epigastric perforator (DIEP) flap reconstruction in patients with breast cancer requiring mastectomy. METHODS: We conducted a prospective, non-randomised, feasibility study at two National Health Service trusts in the UK. Eligible patients were women aged older than 18 years with a laboratory diagnosis of primary breast cancer requiring mastectomy and post-mastectomy radiotherapy, who were suitable for DIEP flap reconstruction. Preoperative radiotherapy started 3-4 weeks after neoadjuvant chemotherapy and was delivered to the breast, plus regional nodes as required, at 40 Gy in 15 fractions (over 3 weeks) or 42·72 Gy in 16 fractions (over 3·2 weeks). Adverse skin radiation toxicity was assessed preoperatively using the Radiation Therapy Oncology Group toxicity grading system. Skin-sparing mastectomy and DIEP flap reconstruction were planned for 2-6 weeks after completion of preoperative radiotherapy. The primary endpoint was the proportion of open breast wounds greater than 1 cm width requiring a dressing at 4 weeks after surgery, assessed in all participants. This study is registered with ClinicalTrials.gov, NCT02771938, and is closed to recruitment. FINDINGS: Between Jan 25, 2016, and Dec 11, 2017, 33 patients were enrolled. At 4 weeks after surgery, four (12·1%, 95% CI 3·4-28·2) of 33 patients had an open breast wound greater than 1 cm. One (3%) patient had confluent moist desquamation (grade 3). There were no serious treatment-related adverse events and no treatment-related deaths. INTERPRETATION: Preoperative radiotherapy followed by skin-sparing mastectomy and immediate DIEP flap reconstruction is feasible and technically safe, with rates of breast open wounds similar to those reported with post-mastectomy radiotherapy. A randomised trial comparing preoperative radiotherapy with post-mastectomy radiotherapy is required to precisely determine and compare surgical, oncological, and breast reconstruction outcomes, including quality of life. FUNDING: Cancer Research UK, National Institute for Health Research.

Assessment of Technical Skills in Axillary Lymph Node Dissection.

OBJECTIVE: A simulator to enable safe practice and assessment of ALND has been designed, and face, content and construct validity has been investigated. SUMMARY AND BACKGROUND DATA: The reduction in the number of ALNDs conducted has led to decreased resident exposure and confidence. METHODS: A cross-sectional multicenter observational study was carried out between July 2017 and August 2018. Following model development, 30 surgeons of varying experience (n = "experts," n = 11 "senior residents," and n = 10 "junior residents") were asked to perform a simulated ALND. Face and content validity questionnaires were administered immediately after ALND. All ALND procedures were retrospectively assessed by 2 attending breast surgeons, blinded to operator identity, using a video-based assessment tool, and an end product assessment tool. RESULTS: Statistically significant differences between groups were observed across all operative subphases on the axillary clearance assessment tool (P < 0.001). Significant differences between groups were observed for overall procedure quality (P < 0.05) and total number of lymph nodes harvested (P < 0.001). However, operator grade could not be distinguished across other end product variables such as axillary vein damage (P = 0.864) and long thoracic nerve injury (P = 0.094). Overall, participants indicated that the simulator has good anatomical (median score >7) and procedural realism (median score >7). CONCLUSIONS: Video-based analysis demonstrates construct validity for ALND assessment. Given reduced ALND exposure, this simulation is a useful adjunct for both technical skills training and formative Deanery or Faculty administered assessments.

American Society of Breast Surgeons' Practice Patterns for Patients at Risk and Affected by Breast Cancer-Related Lymphedema.

BACKGROUND: In 2017, the American Society of Breast Surgeons (ASBrS) published expert panel recommendations for patients at risk for breast cancer-related lymphedema (BCRL) and those affected by BCRL. This study sought to determine BCRL practice patterns. METHODS: A survey was sent to 2975 ASBrS members. Questions evaluated members' clinical practice type, practice duration, and familiarity with BCRL recommendations. Descriptive statistics, the chi-square test, and Fisher's exact test were used. RESULTS: Of the ASBrS members surveyed, 390 (13.1%) responded. Most of the breast surgeons (58.5%, 228/390) indicated unfamiliarity with recommendations. Nearly all respondents (98.7%, 385/390) educate at-risk patients. Most (60.2%, 234/389) instruct patients to avoid venipuncture, injection or blood pressure measurements in the at-risk arm, and 35.6% (138/388) recommend prophylactic compression sleeve use during air travel. Nearly all (97.7%, 380/389) encourage those at-risk to exercise, including resistance exercise (86.2%, 331/384). Most do not perform axillary reverse mapping (ARM) (67.9%, 264/389) or a lymphatic preventive healing approach (LYMPHA) (84.9%, 331/390). Most (76.1%, 296/389) screen at-risk patients for BCRL. The most frequently used screening tools include self-reported symptoms (81%, 255/315), circumferential tape measure (54%, 170/315) and bioimpedance spectroscopy (27.3%, 86/315). After a BCRL diagnosis, most (90%, 351/390) refer management to a lymphedema-certified physical therapist. For affected patients, nearly all encourage exercise (98.7%, 384/389). Many (49%, 191/390) refer affected patients for consideration of lymphovenous bypass or lymph node transfer. CONCLUSION: Most respondents were unfamiliar with the ASBrS expert panel recommendations for patients at risk for BCRL and those affected by BCRL. Opportunities exist to increase awareness of best practices and to acquire ARM and LYMPHA technical expertise.

Meta-analysis Comparing Fluorescence Imaging with Radioisotope and Blue Dye-Guided Sentinel Node Identification for Breast Cancer Surgery.

INTRODUCTION: Conventional methods for axillary sentinel lymph node biopsy (SLNB) are fraught with complications such as allergic reactions, skin tattooing, radiation, and limitations on infrastructure. A novel technique has been developed for lymphatic mapping utilizing fluorescence imaging. This meta-analysis aims to compare the gold standard blue dye and radioisotope (BD-RI) technique with fluorescence-guided SLNB using indocyanine green (ICG). METHODS: This study was registered with PROSPERO (CRD42019129224). The MEDLINE, EMBASE, Scopus, and Web of Science databases were searched using the Medical Subject Heading (MESH) terms 'Surgery' AND 'Lymph node' AND 'Near infrared fluorescence' AND 'Indocyanine green'. Studies containing raw data on the sentinel node identification rate in breast cancer surgery were included. A heterogeneity test (using Cochran's Q) determined the use of fixed- or random-effects models for pooled odds ratios (OR). RESULTS: Overall, 1748 studies were screened, of which 10 met the inclusion criteria for meta-analysis. ICG was equivalent to radioisotope (RI) at sentinel node identification (OR 2.58, 95% confidence interval [CI] 0.35-19.08, p < 0.05) but superior to blue dye (BD) (OR 9.07, 95% CI 6.73-12.23, p < 0.05). Furthermore, ICG was superior to the gold standard BD-RI technique (OR 4.22, 95% CI 2.17-8.20, p < 0.001). CONCLUSION: Fluorescence imaging for axillary sentinel node identification with ICG is equivalent to the single technique using RI, and superior to the dual technique (RI-BD) and single technique with BD. Hospitals using RI and/or BD could consider changing their practice to ICG given the comparable efficacy and improved safety profile, as well as the lesser burden on hospital infrastructure.

The Impact of Temporal Variation in Indocyanine Green Administration on Tumor Identification During Fluorescence Guided Breast Surgery.

BACKGROUND: On average, 21% of women in the USA treated with Breast Conserving Surgery (BCS) undergo a second operation because of close positive margins. Tumor identification with fluorescence imaging could improve positive margin rates through demarcating location, size, and invasiveness of tumors. We investigated the technique's diagnostic accuracy in detecting tumors during BCS using intravenous indocyanine green (ICG) and a custom-built fluorescence camera system. METHODS: In this single-center prospective clinical study, 40 recruited BCS patients were sub-categorized into two cohorts. In the first 'enhanced permeability and retention' (EPR) cohort, 0.25 mg/kg ICG was injected ~ 25 min prior to tumor excision, and in the second 'angiography' cohort, ~ 5 min prior to tumor excision. Subsequently, an in-house imaging system was used to image the tumor in situ prior to resection, ex vivo following resection, the resection bed, and during grossing in the histopathology laboratory to compare the technique's diagnostic accuracy between the cohorts. RESULTS: The two cohorts were matched in patient and tumor characteristics. The majority of patients had invasive ductal carcinoma with concomitant ductal carcinoma in situ. Tumor-to-background ratio (TBR) in the angiography cohort was superior to the EPR cohort (TBR = 3.18 ± 1.74 vs 2.10 ± 0.92 respectively, p = 0.023). Tumor detection reached sensitivity and specificity scores of 0.82 and 0.93 for the angiography cohort and 0.66 and 0.90 for the EPR cohort, respectively (p = 0.1051 and p = 0.9099). DISCUSSION: ICG administration timing during the angiography phase compared with the EPR phase improved TBR and diagnostic accuracy. Future work will focus on image pattern analysis and adaptation of the camera system to targeting fluorophores specific to breast cancer.

Can we see what is invisible? The role of MRI in the evaluation and management of patients with pathological nipple discharge.

INTRODUCTION: The aim of this study was to determine the ability of MRI to identify and assess the extent of disease in patients with pathological nipple discharge (PND) with an occult malignancy not evident on standard pre-operative evaluation with mammography and ultrasound. METHODS: Patients presenting to the breast unit of Imperial College Healthcare NHS Trust between December 2009 and December 2018 with PND and normal imaging were enrolled in the study. Pre-operative bilateral breast MRI was performed in all patients as part of our protocol and all patients were offered diagnostic microdochectomy. RESULTS: A total of 82 patients fulfilled our selection criteria and were enrolled in our study. The presence of an intraductal papilloma (IDP) was identified as the cause of PND in 38 patients (46.3%), 14 patients had duct ectasia (DE-17%) and 5 patients had both an IDP and DE. Other benign causes were identified in 11 patients (13.4%). Despite normal mammography and ultrasound a malignancy was identified in 14 patients (17%). Eleven patients had DCIS (13.4%), two had invasive lobular carcinoma and one patient had an invasive ductal carcinoma. The sensitivity of MRI in detecting an occult malignancy was 85.71% and the specificity was 98.53%. The positive predictive value was 92.31% and the negative predictive value was 97.1%. CONCLUSIONS: Although a negative MRI does not exclude the presence of an occult malignancy the high sensitivity and specificity of this diagnostic modality can guide the surgeon and alter the management of patients with PND.

Streamlining Decision Making in Contralateral Risk-Reducing Mastectomy: Impact of PREDICT and BOADICEA Computations.

INTRODUCTION: Patients with sporadic breast cancer (BC) have low contralateral breast cancer risk (CLBCR; approximately 0.7% per annum) and contralateral prophylactic mastectomy (CPM) offers no survival advantage. CPM with autologous reconstruction (AR) has major morbidity and resource implications. OBJECTIVE: The aim of this study was to review the impact of PREDICT survival estimates and lifetime CLBCR scores on decision making for CPM in patients with unilateral BC. METHODS: Of n = 272 consecutive patients undergoing mastectomy and AR, 252 were included. Five- and 10-year survival was computed with the PREDICT(V2) online prognostication tool, using age and clinicopathological factors. Based on family history (FH) and tumor biology, CLBCR was calculated using validated BODICEA web-based software. Survival scores were correlated against CLBCR estimates to identify patients receiving CPM with 'low' CLBCR (< 30% lifetime risk) and poor prognosis (5-year survival < 80%). Patients with 'high' CLBCR receiving unilateral mastectomy (UM) were similarly identified (UK National Institute of Health and Care Excellence [NICE] criteria for CPM, ≥ 30% lifetime BC risk). Justifications motivating CPM were investigated. RESULTS: Of 252 patients, 215 had UM and 37 had bilateral mastectomy and AR. Only 23 (62%) patients receiving CPM fulfilled the NICE criteria. Of 215 patients, 5 (2.3%) failed to undergo CPM despite high CLBCR and good prognosis. CPMs were performed, at the patient's request, for no clear justification (n = 8), contralateral non-invasive disease, and/or FH (n = 5), FH alone (n = 4) and ipsilateral cancer recurrence-related anxiety (n = 3). CONCLUSION: In the absence of prospective risk estimates of CLBCR and prognosis, certain patients receive CPM and reconstruction despite modest CLBCR, yet a proportion of patients with good prognoses and substantial risk are not undergoing CPM.

Co-regulated gene expression by oestrogen receptor α and liver receptor homolog-1 is a feature of the oestrogen response in breast cancer cells.

Oestrogen receptor α (ERα) is a nuclear receptor that is the driving transcription factor expressed in the majority of breast cancers. Recent studies have demonstrated that the liver receptor homolog-1 (LRH-1), another nuclear receptor, regulates breast cancer cell proliferation and promotes motility and invasion. To determine the mechanisms of LRH-1 action in breast cancer, we performed gene expression microarray analysis following RNA interference for LRH-1. Interestingly, gene ontology (GO) category enrichment analysis of LRH-1-regulated genes identified oestrogen-responsive genes as the most highly enriched GO categories. Remarkably, chromatin immunoprecipitation coupled to massively parallel sequencing (ChIP-seq) to identify genomic targets of LRH-1 showed LRH-1 binding at many ERα binding sites. Analysis of select binding sites confirmed regulation of ERα-regulated genes by LRH-1 through binding to oestrogen response elements, as exemplified by the TFF1/pS2 gene. Finally, LRH-1 overexpression stimulated ERα recruitment, while LRH-1 knockdown reduced ERα recruitment to ERα binding sites. Taken together, our findings establish a key role for LRH-1 in the regulation of ERα target genes in breast cancer cells and identify a mechanism in which co-operative binding of LRH-1 and ERα at oestrogen response elements controls the expression of oestrogen-responsive genes.

Pre-operative chemoradiotherapy followed by mastectomy and breast reconstruction-A systematic review of clinical, oncological, reconstructive and aesthetic outcomes.

BACKGROUND: Pre-operative radiotherapy (PRT) and pre-operative chemoradiotherapy (PCRT) prior to mastectomy and immediate breast reconstruction for locally advanced breast cancer have the potential to reduce radiation late-effects and expedite oncologic treatment. Recent feasibility work indicates that PCRT is safe and technically possible. Here, we present a systematic review of currently available data on clinical, oncological, reconstructive and aesthetic outcomes. METHODS: A prospectively registered search of Medline (Ovid), EMBASE (Ovid), EMCARE (Ovid) and CINAHL (EBSCO) databases was performed in August 2023. Clinical, oncological, reconstructive and aesthetic outcomes were appraised with risk of bias (ROBINS-I) and methodological quality determined (STROBE checklist) for each study. RESULTS: Twenty-two published articles (19 journal articles and 3 abstracts) were identified reporting the outcomes of 1258 patients with median follow-up between 19.0-212.4 months. Patients received neoadjuvant chemotherapy in 20 studies. Rates of locoregional recurrence and overall survival ranged between 0-21.7% and 82.0%-98.3% respectively. Rates of flap loss or necrosis ranged from 0-7.6%. Rates of revisional procedures ranged between 1.9-35.3%. Patient-reported outcomes were reported in 7 studies and were mostly 'good' or 'excellent'. CONCLUSION: PRT and PCRT preceding mastectomy and breast reconstruction produce acceptable oncological outcomes with rates of surgical complication and reconstructive outcomes within normal limits, however, the majority of available studies are of low methodological quality and at high risk of bias. A pragmatic randomised trial comparing PRT versus PMRT in the setting of breast reconstruction is now urgently required to guide surgical practice.

Pre-operative Radiotherapy And Deep Inferior Epigastric Artery Perforator (DIEP) flAp study (PRADA): Aesthetic outcome and patient satisfaction at one year.

INTRODUCTION: The optimal combination of radiotherapy and breast reconstruction has not yet been defined. Post-mastectomy radiotherapy (PMRT) has deleterious effects on breast reconstruction, leading to caution amongst surgeons. Pre-operative radiotherapy (PRT) is a growing area of interest, is demonstrated to be safe, and spares autologous flaps from radiotherapy. This study evaluates the aesthetic outcome of PRT and deep inferior epigastric artery perforator (DIEP) flap reconstruction within the Pre-operative Radiotherapy And Deep Inferior Epigastric artery Perforator (DIEP) flAp (PRADA) cohort. METHODS: PRADA was an observational cohort study designed to evaluate the feasibility and safety of PRT for women undergoing neoadjuvant chemotherapy and DIEP reconstruction. Panel evaluation of 3D surface images (3D-SIs) and patient-reported outcome measures (BREAST-Q) for a subset of women in the study were compared with those of a DIEP-PMRT cohort who had undergone DIEP reconstruction and PMRT. RESULTS: Seventeen out of 33 women from the PRADA study participated in this planned substudy. Twenty-eight women formed the DIEP-PMRT cohort (median follow-up 23 months). The median (inter-quartile range [IQR]) 'satisfaction with breasts' score at 12 months for the PRADA cohort was significantly better than the DIEP-PMRT cohort (77 [72-87] versus 64 [54-71], respectively), p=0.01). Median [IQR] panel evaluation (5-point scale) was also significantly better for the PRADA cohort than for the DIEP-PMRT cohort (4.3 [3.9-4.6] versus 3.6 [2.8-4] p=0.003). CONCLUSIONS: Aesthetic outcome for the PRADA cohort was reported to be 'good' or 'excellent' in 93% of cases using a bespoke panel assessment with robust methodology. Patient satisfaction at one year is encouraging and superior to DIEP-PMRT at 23 months. Switching surgery-radiotherapy sequencing leads to similar breast aesthetic outcomes and warrants further large-scale, multi-centre evaluation in a randomised trial.

The estrogen receptor-alpha-induced microRNA signature regulates itself and its transcriptional response.

Following estrogenic activation, the estrogen receptor-alpha (ERalpha) directly regulates the transcription of target genes via DNA binding. MicroRNAs (miRNAs) modulated by ERalpha have the potential to fine tune these regulatory systems and also provide an alternate mechanism that could impact on estrogen-dependent developmental and pathological systems. Through a microarray approach, we identify the subset of microRNAs (miRNAs) modulated by ERalpha, which include upregulation of miRNAs derived from the processing of the paralogous primary transcripts (pri-) mir-17-92 and mir-106a-363. Characterization of the mir-17-92 locus confirms that the ERalpha target protein c-MYC binds its promoter in an estrogen-dependent manner. We observe that levels of pri-mir-17-92 increase earlier than the mature miRNAs derived from it, implicating precursor cleavage modulation after transcription. Pri-mir-17-92 is immediately cleaved by DROSHA to pre-miR-18a, indicating that its regulation occurs during the formation of the mature molecule from the precursor. The clinical implications of this novel regulatory system were confirmed by demonstrating that pre-miR-18a was significantly upregulated in ERalpha-positive compared to ERalpha-negative breast cancers. Mechanistically, miRNAs derived from these paralogous pri-miRNAs (miR-18a, miR-19b, and miR-20b) target and downregulate ERalpha, while a subset of pri-miRNA-derived miRNAs inhibit protein translation of the ERalpha transcriptional p160 coactivator, AIB1. Therefore, different subsets of miRNAs identified act as part of a negative autoregulatory feedback loop. We propose that ERalpha, c-MYC, and miRNA transcriptional programs invoke a sophisticated network of interactions able to provide the wide range of coordinated cellular responses to estrogen.

The prevention and treatment of breast cancer- related lymphedema: A review.

Background: Breast cancer- related lymphedema (BCRL) affects about 3 to 5 million patients worldwide, with about 20,000 per year in the United States. As breast cancer mortality is declining due to improved diagnostics and treatments, the long-term effects of treatment for BCRL need to be addressed. Methods: The American Society of Breast Surgeons Lymphatic Surgery Working Group conducted a large review of the literature in order to develop guidelines on BCRL prevention and treatment. This was a comprehensive but not systematic review of the literature. This was inclusive of recent randomized controlled trials, meta-analyses, and reviews evaluating the prevention and treatment of BCRL. There were 25 randomized clinical trials, 13 systemic reviews and meta-analyses, and 87 observational studies included. Results: The findings of our review are detailed in the paper, with each guideline being analyzed with the most recent data that the group found evidence of to suggest these recommendations. Conclusions: Prevention and treatment of BCRL involve a multidisciplinary team. Early detection, before clinically apparent, is crucial to prevent irreversible lymphedema. Awareness of risk factors and appropriate practice adjustments to reduce the risk aids are crucial to decrease the progression of lymphedema. The treatment can be costly, time- consuming, and not always effective, and therefore, the overall goal should be prevention.

Patient-level costs of staged unilateral versus immediate bilateral symmetrization mammoplasty in breast-conserving surgery.

BACKGROUND: Following therapeutic mammoplasty (TM), the contralateral breast may require a later balancing procedure to optimize shape and symmetry. The alternative is to offer patients simultaneous TM with immediate contralateral symmetrization via a dual-surgeon approach, with the goal of reducing costs and minimizing the number of subsequent hospital appointments in an era of COVID-19 surges. The aim of this cost-consequence analysis is to characterize the cost-benefit of immediate bilateral symmetrization dual-operator mammoplasty versus staged unilateral single operator for breast cancer surgery. METHOD: A prospective single-centre observational study was conducted at an academic teaching centre for breast cancer surgery in the UK. Pseudonymized data for clinicopathological variables and procedural care information, including the type of initial breast-conserving surgery and subsequent reoperation(s), were extracted from the electronic patient record. Financial data were retrieved using the Patient-Level Information and Costing Systems. RESULTS: Between April 2014 and March 2020, 232 women received either immediate bilateral (n = 44), staged unilateral (n = 57) for breast cancer, or unilateral mammoplasty alone (n = 131). The median (interquartile range (i.q.r.)) additional cost of unilateral mammoplasty with staged versus immediate bilateral mammoplasty was €5500 (€4330 to €6570) per patient (P < 0.001), which represents a total supplementary financial burden of €313 462 to the study institution. There was no significant difference between groups in age, Charlson comorbidity index, operating minutes, time to adjuvant radiotherapy in months, or duration of hospital stay. CONCLUSION: Synchronous dual-surgeon immediate bilateral TM can deliver safe immediate symmetrization and is financially beneficial, without delay to receipt of adjuvant therapy, or additional postoperative morbidity.

Indocyanine green fluorescence image processing techniques for breast cancer macroscopic demarcation.

Re-operation due to disease being inadvertently close to the resection margin is a major challenge in breast conserving surgery (BCS). Indocyanine green (ICG) fluorescence imaging could be used to visualize the tumor boundaries and help surgeons resect disease more efficiently. In this work, ICG fluorescence and color images were acquired with a custom-built camera system from 40 patients treated with BCS. Images were acquired from the tumor in-situ, surgical cavity post-excision, freshly excised tumor and histopathology tumour grossing. Fluorescence image intensity and texture were used as individual or combined predictors in both logistic regression (LR) and support vector machine models to predict the tumor extent. ICG fluorescence spectra in formalin-fixed histopathology grossing tumor were acquired and analyzed. Our results showed that ICG remains in the tissue after formalin fixation. Therefore, tissue imaging could be validated in freshly excised and in formalin-fixed grossing tumor. The trained LR model with combined fluorescence intensity (pixel values) and texture (slope of power spectral density curve) identified the tumor's extent in the grossing images with pixel-level resolution and sensitivity, specificity of 0.75 ± 0.3, 0.89 ± 0.2.This model was applied on tumor in-situ and surgical cavity (post-excision) images to predict tumor presence.

The liver receptor homolog-1 regulates estrogen receptor expression in breast cancer cells.

Estrogen receptor-α (ER) is expressed in the great majority of breast cancers, and the inhibition of ER action is a key part of breast cancer treatment. The inhibition of ER action is achieved using anti-estrogens, primarily tamoxifen, and with aromatase inhibitors that inhibit estrogen biosynthesis, thereby preventing ER activation. However, resistance to these therapies is common. With the aim of identifying new molecular targets for breast cancer therapy, we have identified the liver receptor homolog-1 (LRH-1) as an estrogen-regulated gene. RNA interference and over-expression studies were used to investigate the role of the LRH-1 in regulating breast cancer growth and to identify the targets of an LRH-1 action. Promoter recruitment was determined using reporter gene and chromatin immunoprecipitation (ChIP) assays. We show that LRH-1 regulates breast cancer cell growth by regulating the ER expression. Reporter gene and in vitro DNA-binding assays identified an LRH-1-binding site in the ER gene promoter, and ChIP assays have demonstrated in vivo binding at this site. We also provide evidence for new LRH-1 variants in breast cancer cells arising from the use of alternative promoters. Previous studies have shown that LRH-1 functions in estrogen biosynthesis by regulating aromatase expression. Our findings extend this by highlighting LRH-1 as a key regulator of the estrogen response in breast cancer cells through the regulation of ER expression. Hence, inhibition of LRH-1 could provide a powerful new approach for the treatment of endocrine-resistant breast cancer.

Transient over-expression of estrogen receptor-α in breast cancer cells promotes cell survival and estrogen-independent growth.

Estrogen receptor-α (ERα) positive breast cancer frequently responds to inhibitors of ERα activity, such as tamoxifen, and/or to aromatase inhibitors that block estrogen biosynthesis. However, many patients become resistant to these agents through mechanisms that remain unclear. Previous studies have shown that expression of ERα in ERα-negative breast cancer cell lines frequently inhibits their growth. In order to determine the consequence of ERα over-expression in ERα-positive breast cancer cells, we over-expressed ERα in the MCF-7 breast cancer cell line using adenovirus gene transduction. ERα over-expression led to ligand-independent expression of the estrogen-regulated genes pS2 and PR and growth in the absence of estrogen. Interestingly, prolonged culturing of these cells in estrogen-free conditions led to the outgrowth of cells capable of growth in cultures from ERα transduced, but not in control cultures. From these cultures a line, MLET5, was established which remained ERα-positive, but grew in an estrogen-independent manner. Moreover, MLET5 cells were inhibited by anti-estrogens showing that ERα remains important for their growth. Gene expression microarray analysis comparing MCF-7 cells with MLET5 highlighted apoptosis as a major functional grouping that is altered in MLET5 cells, such that cell survival would be favoured. This conclusion was further substantiated by the demonstration that MLET5 show resistance to etoposide-induced apoptosis. As the gene expression microarray analysis also shows that the apoptosis gene set differentially expressed in MLET5 is enriched for estrogen-regulated genes, our findings suggest that transient over-expression of ERα could lead to increased cell survival and the development of estrogen-independent growth, thereby contributing to resistance to endocrine therapies in breast cancer patients.