Obesity-associated changes in molecular biology of primary breast cancer

Obesity is associated with an increased risk of developing breast cancer (BC) and worse prognosis in BC patients, yet its impact on BC biology remains understudied in humans. This study investigates how the biology of untreated primary BC differs according to patients' body mass index (BMI) using data from >2,000 patients. We identify several genomic alterations that are differentially prevalent in overweight or obese patients compared to lean patients. We report evidence supporting an ageing accelerating effect of obesity at the genetic level. We show that BMI-associated differences in bulk transcriptomic profile are subtle, while single cell profiling allows detection of more pronounced changes in different cell compartments. These analyses further reveal an elevated and unresolved inflammation of the BC tumor microenvironment associated with obesity, with distinct characteristics contingent on the estrogen receptor status. Collectively, our analyses imply that obesity is associated with an inflammaging-like phenotype. We conclude that patient adiposity may play a significant role in the heterogeneity of BC and should be considered for BC treatment tailoring.

Abstract P3-09-18: The association between genomic alterations and body mass index in patients with early breast cancer

Background: High body mass index (BMI) is an established risk factor for developing breast cancer (BC), especially estrogen receptor (ER)-positive, and also has been associated with adverse survival. Still, patients with BC are currently treated independently of their BMI given limited understandings of the association between BC biology and patient adiposity. In this study, using retrospective data retrieved from two large BC studies, we aimed to identify genomic alterations of primary BC that are associated with BMI in the most common histological BC subtype - invasive carcinoma of no special type (NST). Patients, Data and Methods: Clinicopathological and genomic alteration data were retrieved from two study cohorts: METABRIC (Pereira et al. 2016) and ICGC (Nik-Zainal et al. 2016), with BMI recorded at the time of diagnosis and represented as either a continuous variable or a categorical variable of three categories - lean, overweight and obese. Stratification according to ER and HER2 status resulted in two focused subgroups: NST ER+/HER2- (n=392) and NST ER-/HER2- (n=152). Mutations classified as oncogenic using a set of predefined criteria were used to determine gene-level mutation status. Copy number alteration (CNA) calls were distinguished into three event types: amplification, hemizygous deletion and homozygous deletion. We used multivariable Firth’s logistic regression models with the presence of a genomic alteration as the response variable, BMI as the predicting variable of interest, and data cohort (METABRIC vs ICGC), age group (≤50 vs >50) and tumor grade (I & II vs III) as covariates, to assess the associations between BMI and recurrent gene-level genomic alterations, including gene mutations and CNAs. In a similar manner, we performed multivariable linear regression analysis, adjusting for age and tumor grade, to evaluate the associations of BMI with mutational signatures (MS) and tumor mutational burden in the ICGC NST subsets where these data are available. Results: Considering BMI as a categorical variable, we observed in the NST ER+/HER2- subgroup that PIK3CA was significantly less frequently mutated in obese compared to lean patients (33% vs 46%, odds ratio (OR) = 0.57 (95% confidence interval = (0.33, 0.97)), p = .039), while PTEN and TBX3 showed an increased frequency in overweight (6% vs 1%, OR = 4.14 (1.1, 22.34), p = .034) and obese (8% vs 1%, OR = 7.41 (1.82, 70.65), p = .008) patients, respectively. Regression analyses with BMI as a continuous variable revealed an increased prevalence of mutations in CDH1 and TBX3 genes as BMI increases by 1kg/m2 (OR = 1.14 (1.05, 1.24), p = .002, and OR = 1.13 (1.04, 1.22), p = .005, respectively) in patients with NST ER+/HER2- BC. No associations between BMI and oncogenic mutations was observed in the NST ER-/HER2- subgroup. Interrogation of gene-level CNAs in both subgroups demonstrated differences according to BMI in the prevalence of CNAs affecting a number of genes, many of which are known or have been presented with evidence to be involved in regulation of or regulated by hallmark pathways of BC, such as the MAPK/ERK, JAK/STAT and Wnt/β-catenin signaling pathways. We report a strong positive association between the single-base substitution signature 1 (SBS1), an age-correlated MS, and both continuous (coefficient (coef) = 18.3 (7.7, 28.9), p < .001) and categorical BMI (obese vs lean, coef = 336.3 (187.9, 484.8), p < .001) in the ICGC NST ER+/HER2- subgroup. Conclusion: This exploratory retrospective study suggests that the genomic profiles of primary BC may differ according to BMI. Clinical implications of these differences, especially the decreased prevalence of PIK3CA mutations in obese patients in the context of alpelisib, warrant further investigation. These results however indicate that patient adiposity should be taken into account in the era of personalized medicine.

Citation Format: Ha-Linh Nguyen, Tatjana Geukens, Marion Maetens, Karen Van Baelen, Maxim De Schepper, Sophia Leduc, Edoardo Isnaldi, Sam Aparicio, Ake Borg, Jane Brock, Annegien Broeks, Carlos Caldas, Andrew Green, Hazem Khout, Eyfjörð Jórunn, Stian Knappskog, Savitri Krishnamurthy, Sunil Lakhani, Anita Langerod, John WM Martens, Leigh Murphy, Serena Nik-Zainal, Colin Purdie, Emad Rakha, Andrea Richardson, Anne Salomon, Peter Simpson, Christos Sotiriou, Paul Span, Benita Kiat-Tee Tan, Alastair Thompson, Stefania Tommasi, Marc Van de Vijver, Steven Van Laere, Alain Viari, Giuseppe Floris, Elia Biganzoli, François Richard, Christine Desmedt. The association between genomic alterations and body mass index in patients with early breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-09-18.

Post-intensive care syndrome following cardiothoracic critical care: Feasibility of a complex intervention

OBJECTIVES

To describe the long-term outcomes of cardiac intensive care unit patients and their primary caregivers, and to explore the feasibility of implementing a complex intervention, designed to support problems associated with post-intensive care syndrome and post-intensive care syndrome-family, in the year following discharge from the cardiac intensive care unit.

DESIGN

A complex multidisciplinary rehabilitation programme, delivered as a quality improvement initiative, in a single centre in the West of Scotland. Outcomes were measured using surveys of health related quality of life, self efficacy, anxiety, depression, pain, caregiver strain, and insomnia.

PARTICIPANTS

Patients and their caregivers were invited to participate 12 weeks after hospital discharge. Twenty-seven patients and 23 caregivers attended the programme.

RESULTS

Over 90% of patients had problems in at least one quality of life domain at baseline, 41% of patients had symptoms of anxiety and 22% had symptoms of depression. During the baseline visit, caregiver strain was present in 20% of caregivers, 57% had symptoms of anxiety, and 35% had symptoms of depression. Improvements in outcomes were seen in both patients and caregivers at 1-year follow-up. The programme was implemented, and iterative learning obtained about the content and the operationalization of the service, in order to understand feasibility.

CONCLUSION

This small-scale quality improvement project has demonstrated that this complex multidisciplinary rehabilitation programme is feasible and has positive implications for patients following discharge from the cardiac intensive care unit, and their caregivers.

Predictors of pathological complete response to neoadjuvant treatment and changes to post-neoadjuvant HER2 status in HER2-positive invasive breast cancer

The response of human epidermal growth factor receptor2 (HER2)- positive breast cancer (BC) patients to anti-HER2 targeted therapy is significant. However, the response is not uniform and a proportion of HER2-positive patients do not respond. This study aims to identify predictors of response in the neoadjuvant treatment and to assess the discordance rate of HER2 status between pre- and post-treatment specimens in HER2-positive BC patients. The study group comprised 500 BC patients treated with neoadjuvant chemotherapy (NACT) and/or neoadjuvant anti-HER2 therapy and surgery who had tumours that were 3+ or 2+ with HER2 immunohistochemistry (IHC). HER2 IHC 2+ tumours were classified into five groups by fluorescence in situ hybridisation (FISH) according to the 2018 ASCO/CAP guidelines of which Groups 1, 2 and 3 were considered HER2 amplified. Pathological complete response (pCR) was more frequent in HER2 IHC 3+ tumours than in HER2 IHC 2+/HER2 amplified tumours, when either in receipt of NACT alone (38% versus 13%; p = 0.22) or neoadjuvant anti-HER2 therapy (52% versus 20%; p < 0.001). Multivariate logistic regression analysis showed that HER2 IHC 3+ and histological grade 3 were independent predictors of pCR following neoadjuvant anti-HER2 therapy. In the HER2 IHC 2+/HER2 amplified tumours or ASCO/CAP FISH Group 1 alone, ER-negativity was an independent predictor of pCR following NACT and/or neoadjuvant anti-HER2 therapy. In the current study, 22% of HER2-positive tumours became HER2-negative by IHC and FISH following neoadjuvant treatment, the majority (74%) HER2 IHC 2+/HER2 amplified tumours. Repeat HER2 testing after neoadjuvant treatment should therefore be considered.

The prognostic impact of mode of detection of axillary metastases for women with invasive breast cancer: A retrospective observational study

AIM

To identify the breast cancer specific survival (BCSS) associated with nodal metastasis identified by axillary core biopsy (ACB), and by sentinel node biopsy (SNB) compared with node negative patients. A further aim was to assess the prognostic effects of axillary ultrasound (US) features and amount of tumour in ACB specimens.

METHODS

Consecutive patients with cancer were identified from a database of US lesions undergoing breast biopsy. The three study groups were: a) those with metastasis identified by ACB, b) those undergoing immediate surgery with positive SNB and c) those undergoing immediate surgery with a negative SNB. US features and the amount of tumour in the ACB specimen were assessed by review of US images and pathological reports. BCSS was assessed using Kaplan Meier survival curves.

RESULTS

967 patients were included, with mean follow-up of 6.0 yrs. There were 90 breast cancer deaths: 26% of those with a positive ACB, 11% with a positive SNB and 4% of those with a negative SNB. BCSS was significantly different between the groups (p < 0.001) with hazard ratio, compared with the negative SNB group, of 7.8 (95% CI 4.4-13.7) for patients with positive ACB and 2.5 (95% CI 1.3-4.6) for positive SNB. Axillary US findings and assessment of the amount of tumour in the ACB did not influence survival.

CONCLUSION

This study suggests that women with a positive ACB have a worse BCSS compared to those with a positive SNB. This should be borne in mind when systemic therapy is being considered.

Abstract A16: Metformin is a potential nontoxic adjuvant to enhance the efficacy of non-PDL1/PD-1 targeting immune therapies

Investigations into various immunotherapies combined with conventional anticancer drugs are ongoing to increase therapeutic efficacy. However, combination therapy generally increases the risk of side effects. To achieve high efficacy with minimal side effects, nontoxic adjuvants should be identified and appropriate combinations should be designed based on the functional mechanism. In this regard, metformin can be an attractive candidate for immunotherapeutic adjuvants. Metformin is a widely used oral medication for type 2 diabetes (T2D) and has been recognized as a safe and well-tolerated drug through several decades of clinical experience. Interestingly, metformin also exhibits antitumor effects as several case-control studies for T2D patients indicated that metformin reduces the incidence of various cancer types. However, the functions and the detailed mechanism of metformin related to cancer immunity are not fully understood. In this study, we investigated the antitumor effects of metformin in relation to cancer immunity in the tumor microenvironment. Our data showed that AMPK activated by metformin decreases the expression of PD-L1 in the cancer cells, blocking PD-L1’s ability to aid cancer cells in escaping immune surveillance. This is caused by the mechanism in which phosphorylation of PD-L1 at S195 induces an abnormal glycan structure that leads to endoplasmic reticulum-associated degradation. In addition, we have obtained human breast tumor tissues from a previous clinical trial investigating metformin as treatment for breast cancer patients. The data from human tumor tissues also provided strong support to our current conclusion, namely AMPK activated by metformin reduces the level of PD-L1. On the basis of these results, we validated the possibility of metformin as an adjuvant to boost the efficacy of previous immunotherapy without toxicity. Our findings suggest that metformin has strong potential to be used as an adjuvant for immunotherapy. Metformin is expected to have synergistic effect with various non-PDL1/PD-1 targeting immune therapies without additional toxicity.

Citation Format: Jong-Ho Cha, Wen-Hao Yang, Weiya Xia, Yongkun Wei, Li-Chuan Chan, Seung-Oe Lim, Chia-Wei Li, Jennifer Hsu, Hung-Ling Wang, Chu-Wei Kuo, Wei-Chao Chang, Sirwan Hadad, Colin Purdie, Aaron McCoy, Jennifer Litton, Elizabeth Mittendorf, Stacy Moulder, William Symmans, Alastair M Thompson, Helen Piwnica-Worms, Chung-Hsuan Chen, Kay-Hooi Khoo, Mien-Chie Hung. Metformin is a potential nontoxic adjuvant to enhance the efficacy of non-PDL1/PD-1 targeting immune therapies [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2018 Nov 27-30; Miami Beach, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(4 Suppl):Abstract nr A16.

Preoperative prediction of margin requirement following a core biopsy result suggestive of a phyllodes tumour

AIM

To determine if imaging features of lesions with a core biopsy suggestive of a phyllodes tumour can be used to identify which lesions require surgical excision with margins.

MATERIALS AND METHODS

Thirty-one lesions were identified from a prospective database of ultrasound visible masses. Demographic, mammographic, and ultrasound features were assessed while blinded to surgical outcome. Features of those lesions requiring a margin and those that did not were compared. Statistical significance was established using the chi-square test and receiver operating characteristic (ROC) curves.

RESULTS

Thirteen lesions (42%) required a margin and 18 lesions (58%) did not. Features found significantly more frequently in those requiring a margin were a poorly defined margin on mammography (7/9 [78%] versus 4/13 [31%]; p=0.04) and at ultrasound, an irregular margin (8/13 [62%] versus 3/18 [17%]; p=0.01), micro-lobulations (7/13 [54%] versus 3/18 [17%]; p=0.028), mixed echogenicity (9/13 [69%] versus 1/18 [6%]; p=0.0002), echogenic clefts (6/13 [46%] versus 1/18 [6%]; p=0.007), posterior enhancement (9/11 [82%] versus 6/18 [33%]; p=0.01), large size (p=0.003) and stiffness at shear-wave elastography (p=0.026). All six screen-detected lesions were benign.

CONCLUSIONS

There are multiple preoperative features that can be used to guide surgical management of lesions with a preoperative core biopsy result suggestive of a phyllodes tumour.

Percutaneous sentinel node removal using a vacuum-assisted needle biopsy in women with breast cancer: a feasibility and acceptability study

AIMS

To assess the feasibility and acceptability of large-gauge percutaneous removal of the axillary sentinel lymph node (SLN) using dual gamma probe and ultrasound guidance.

MATERIALS AND METHODS

Technetium nanocolloid was administered the day before surgery. On the day of surgery, potential SLNs were identified with gamma probe and ultrasound scanning. A 7 G vacuum-assisted biopsy (VAB) device was inserted percutaneously deep to the target node and the node(s) removed. The gamma probe was used to confirm removal of radiolabelled tissue. At surgery, any residual radiolabelled or blue nodes were removed. Morbidity was assessed via (1) a pain questionnaire immediately after the percutaneous procedure, (2) relevant items from the FACT B+4 questionnaire 7-10 days after surgery, and (3) case note review 1 month after surgery.

RESULTS

Twenty-two patients consented and 20 patients underwent the procedure. Radiolabelled nodal tissue was obtained in 18/20 (90%). The mean procedure time was 11 minutes. Four of 18 patients had metastatic disease identified in the VAB excision tissue with 100% sensitivity for axillary metastasis. At axillary surgery, additional intact SLN or fragments were found in 14 patients. No additional metastatic disease was found at surgery. One patient suffered a pneumothorax during instillation of local anaesthetic. The median pain score was 10/100 by visual analogue scale. Immediate post-procedure haematoma was common (14 of 20) and prolonged manual compression frequent.

CONCLUSION

VAB removal of sentinel nodes using dual scanning is feasible. Although preliminary sensitivity and specificity levels are encouraging, complications may discourage widespread implementation.

Mutational mechanisms of amplifications revealed by analysis of clustered rearrangements in breast cancers

Background

Complex clusters of rearrangements are a challenge in interpretation of cancer genomes. Some clusters of rearrangements demarcate clear amplifications of driver oncogenes but others are less well understood. A detailed analysis of rearrangements within these complex clusters could reveal new insights into selection and underlying mutational mechanisms.

Patients and methods

Here, we systematically investigate rearrangements that are densely clustered in individual tumours in a cohort of 560 breast cancers. Applying an agnostic approach, we identify 21 hotspots where clustered rearrangements recur across cancers.

Results

Some hotspots coincide with known oncogene loci including CCND1, ERBB2, ZNF217, chr8:ZNF703/FGFR1, IGF1R, and MYC. Others contain cancer genes not typically associated with breast cancer: MCL1, PTP4A1, and MYB. Intriguingly, we identify clustered rearrangements that physically connect distant hotspots. In particular, we observe simultaneous amplification of chr8:ZNF703/FGFR1 and chr11:CCND1 where deep analysis reveals that a chr8-chr11 translocation is likely to be an early, critical, initiating event.

Conclusions

We present an overview of complex rearrangements in breast cancer, highlighting a potential new way for detecting drivers and revealing novel mechanistic insights into the formation of two common amplicons.

Pre-operative stromal stiffness measured by shear wave elastography is independently associated with breast cancer-specific survival

INTRODUCTION

With the increased use of neoadjuvant therapy for breast cancer, there is a need for pre-operative prediction of prognosis. We aimed to assess the prognostic value of tumour stiffness measured by ultrasound shear wave elastography (SWE).

METHODS

A consecutive cohort of patients with invasive breast cancer underwent breast ultrasound (US) including SWE. The following were recorded prospectively: US diameter, stiffness at SWE, presentation source, core biopsy grade, oestrogen receptor (ER) status and pre-operative nodal status. Breast cancer-specific survival (BCSS) was analysed with regard to US size and stiffness, tumour grade on core biopsy, ER status, presentation mode and pre-operative nodal status. Analysis used Cox proportional hazards regression.

RESULTS

Of the 520 patients, 42 breast cancer and 53 non-breast cancer deaths were recorded at mean follow-up of 5.4 years. Hazard ratios (HR) for tertiles of stiffness were 1, 4.8 and 8.1 (P = 0.0001). HR for 2 groups based on US size < or ≥ 20 mm were 1 and 5.1 (P < 0.0001). HR for each unit increase in tumour grade on core biopsy was 3.9 (P < 0.0001). The HR for ER positivity compared to ER negativity was 0.21 (P < 0.001). BCSS was also associated with presentation mode and pre-operative nodal status. In a multivariable model, stiffness, US size and ER status were independently associated with BCSS.

CONCLUSION

Multiple pre-operative factors including stromal stiffness at SWE have independent prognostic significance. A larger dataset with longer follow-up could be used in the future to construct a pre-operative prognostic model to guide treatment decisions.

Prediction of Pathological Complete Response to Neoadjuvant Chemotherapy for Primary Breast Cancer Comparing Interim Ultrasound, Shear Wave Elastography and MRI

BACKGROUND

 Prediction of pathological complete response (pCR) of primary breast cancer to neoadjuvant chemotherapy (NACT) may influence planned surgical approaches in the breast and axilla. The aim of this project is to assess the value of interim shear wave elastography (SWE), ultrasound (US) and magnetic resonance imaging (MRI) after 3 cycles in predicting pCR.

METHODS

 64 patients receiving NACT had baseline and interim US, SWE and MRI examinations. The mean lesion stiffness at SWE, US and MRI diameter was measured at both time points. We compared four parameters with pCR status: a) Interim mean stiffness ≤ or > 50 kPa; b) Percentage stiffness reduction; c) Percentage US diameter reduction and d) Interim MRI response using RECIST criteria. The Chi square test was used to assess significance.

RESULTS

 Interim stiffness of ≤ or > 50 kPa gave the best prediction of pCR with pCR seen in 10 of 14 (71 %) cancers with an interim stiffness of ≤ 50 kPa, compared to 7 of 50 (14 %) of cancers with an interim stiffness of > 50 kPa, (p < 0.0001) (sensitivity 59 %, specificity 91 %, PPV 71 %, NPV 86 % and diagnostic accuracy 83 %). Percentage reduction in stiffness was the next best parameter (sensitivity 59 %, specificity 85 %, p < 0.0004) followed by reduction in MRI diameter of > 30 % (sensitivity 50 % and specificity 79 %, p = 0.03) and % reduction in US diameter (sensitivity 47 %, specificity 81 %, p = 0.03). Similar results were obtained from ROC analysis.

CONCLUSION

 SWE stiffness of breast cancers after 3 cycles of NACT and changes in stiffness from baseline are strongly associated with pCR after 6 cycles.

Abstract P4-02-07: Preoperative assessment of breast cancer survival using ultrasound diameter and shear wave elastography

This abstract was not presented at the symposium.

Breast cancer genome and transcriptome integration implicates specific mutational signatures with immune cell infiltration

A recent comprehensive whole genome analysis of a large breast cancer cohort was used to link known and novel drivers and substitution signatures to the transcriptome of 266 cases. Here, we validate that subtype-specific aberrations show concordant expression changes for, for example, TP53, PIK3CA, PTEN, CCND1 and CDH1. We find that CCND3 expression levels do not correlate with amplification, while increased GATA3 expression in mutant GATA3 cancers suggests GATA3 is an oncogene. In luminal cases the total number of substitutions, irrespective of type, associates with cell cycle gene expression and adverse outcome, whereas the number of mutations of signatures 3 and 13 associates with immune-response specific gene expression, increased numbers of tumour-infiltrating lymphocytes and better outcome. Thus, while earlier reports imply that the sheer number of somatic aberrations could trigger an immune-response, our data suggests that substitutions of a particular type are more effective in doing so than others.

Shear-wave elastography and greyscale assessment of palpable probably benign masses: is biopsy always required?

OBJECTIVE

To establish if palpable breast masses with benign greyscale ultrasound features that are soft on shear-wave elastography (SWE) (mean stiffness <50 kPa) have a low enough likelihood of malignancy to negate the need for biopsy or follow-up.

METHODS

The study group comprised 694 lesions in 682 females (age range 17-95 years, mean age 56 years) presenting consecutively to our institution with palpable lesions corresponding to discrete masses at ultrasound. All underwent ultrasound, SWE and needle core biopsy. Static greyscale images were retrospectively assigned Breast Imaging Reporting and Data System (BI-RADS) scores by two readers blinded to the SWE and pathology findings, but aware of the patient's age. A mean stiffness of 50 kPa was used as the SWE cut-off for calling a lesion soft or stiff. Histological findings were used to establish ground truth.

RESULTS

No cancer had benign characteristics on both modalities. 466 (99.8%) of the 467 cancers were classified BI-RADS 4a or above. The one malignant lesion classified as BI-RADS 3 was stiff on SWE. 446 (96%) of the 467 malignancies were stiff on SWE. No cancer in females under 40 years had benign SWE features. 74 (32.6%) of the 227 benign lesions were BI-RADS 3 and soft on SWE; so, biopsy could potentially have been avoided in this group.

CONCLUSION

Lesions which appear benign on greyscale ultrasound and SWE do not require percutaneous biopsy or short-term follow-up, particularly in females under 40 years.

ADVANCES IN KNOWLEDGE

None of the cancers had benign characteristics on both greyscale ultrasound and SWE, and 32% of benign lesions were BI-RADS 3 and soft on SWE; lesions that are benign on both ultrasound and SWE may not require percutaneous biopsy or short-term follow-up.

Biomarker discordance: prospective and retrospective evidence that biopsy of recurrent disease is of clinical utility

Prospective studies of biomarker status in primary and recurrent or metastatic breast cancer have confirmed the findings of historical retrospective studies which demonstrate that for biomarkers which influence routine clinical practice, Estrogen Receptor (ER), Progesterone Receptor (PR) and Human Epidermal growth factor Receptor type 2 (HER2), biopsy of recurrent or metastatic disease is essential not only to confirm the presence of malignancy but to guide targeted medical therapy. Historically, discordance rates for the expression of receptors between primary and metastatic tumors, though variable, may have led to suboptimal treatment for a significant proportion of patients. While changes in PR are most common, changes in ER (positive to negative or less frequently negative to positive) and the less common changes in HER2 (usually gain of HER2 amplification) influence subsequent therapy for 1 in 6 patients and may thus impact upon survival. Recognition of the potential for heterogeneity within the primary, between metastatic sites and over time requires further prospective study in breast cancer where the comparability of metastases from multiple sites and the need to biopsy successive recurrences have been less well documented. Recent prospective studies confirm the retrospective evidence that optimal patient care requires appropriate biopsy and pathological assessment of recurrent or metastatic breast cancer.

Abstract P4-19-02: Early experience of patient donation and researcher use of tissues donated to a national breast cancer tissue bank

The need for a specialist breast cancer biobank was recognised through a Gap Analysis conducted by the UK charity, Breast Cancer Campaign (Thompson AM et al., Breast Cancer Res 2008: 10(2); R26). As a result The Breast Cancer Campaign Tissue Bank (www.breastcancertissuebank.org) was launched in 2010 as a coalition of 4 centres of excellence for breast cancer research in the UK. Breast cancer patients presenting to these centres are offered the opportunity to donate surplus tissue and bloods to The Breast Cancer Campaign Tissue Bank. Researchers can apply for these samples by completing a simple on line application form. Here we describe our early experience of patient donation to The Breast Cancer Campaign Tissue Bank and outline the sample requests received from researchers to date. Most of the first year of operation (2010) was spent developing SOPs and ensuring collection protocols were robust, with some limited prospective collection. The collection was pump-primed from existing resources. By 2011 all sites were operational and working to the same standards. Over a 2 year period (Jan 2011 - Dec 2012), over 90% of suitable patients (1803) consented to tissue donation. From these we derived 3951 frozen tissue aliquots, 1517 formalin-fixed paraffin-embedded cases and 2012 blood derivatives (serum, plasma and whole blood). Asian patients were less likely to consent while younger patients tended not to donate blood, but were happy to donate tissue. All male patients consented to tissue and blood donation. At Dec 2012, the total numbers of sample aliquots derived from these donated tissue and blood samples was 22, 127. This includes frozen and formalin-fixed paraffin-embedded tissues, serum, plasma and whole blood. At present, application for tissue samples is restricted to the UK and Ireland but we aim to open to international applications in the near future. All applications are reviewed by an international Tissue Access Committee which includes appropriate clinical and scientific expertise plus representation by patient advocates. At 1st June 2013, seventeen applications had been received, of which 14 were approved. Three applications were rejected, made on the basis that the applicants were not making the best use of the donated material. Thus far, tissues have been dispatched to 9 researchers with 5 in preparation. These include 465 formalin-fixed paraffin-embedded cases and 158 frozen samples, all provided with a basic minimum dataset. Early experience of patient consent was encouraging with patients overall very enthusiastic and willing to donate to our biobanking programme. More research is needed to help understand the barriers in preventing ethnic minorities to donate and the reluctance in some young people to donate blood samples. Interest by the breast cancer research community in accessing samples is steadily rising as the resource becomes more widely known and increased website traffic is translating into applications for tissues. This has been an ambitious multidisciplinary endeavour but we are building a valuable resource to service the needs of the breast cancer research community with the goal of helping translate laboratory results into clinical benefit.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-19-02.

Differentiating benign from malignant solid breast masses: value of shear wave elastography according to lesion stiffness combined with greyscale ultrasound according to BI-RADS classification

Background:

The aim of this study was to assess the performance of shear wave elastography combined with BI-RADS classification of greyscale ultrasound images for benign/malignant differentiation in a large group of patients.

Methods:

One hundred and seventy-five consecutive patients with solid breast masses on routine ultrasonography undergoing percutaneous biopsy had the greyscale findings classified according to the American College of Radiology BI-RADS. The mean elasticity values from four shear wave images were obtained.

Results:

For mean elasticity vs greyscale BI-RADS, the performance results against histology were sensitivity: 95% vs 95%, specificity: 77% vs 69%, Positive Predictive Value (PPV): 88% vs 84%, Negative Predictive Value (NPV): 90% vs 91%, and accuracy: 89% vs 86% (all P>0.05). The results for the combination (positive result from either modality counted as malignant) were sensitivity 100%, specificity 61%, PPV 82%, NPV 100%, and accuracy 86%. The combination of BI-RADS greyscale and shear wave elastography yielded superior sensitivity to BI-RADS alone (P=0.03) or shear wave alone (P=0.03). The NPV was superior in combination compared with either alone (BI-RADS P=0.01 and shear wave P=0.02).

Conclusion:

Together, BI-RADS assessment of greyscale ultrasound images and shear wave ultrasound elastography are extremely sensitive for detection of malignancy.

Invasive breast cancer: relationship between shear-wave elastographic findings and histologic prognostic factors

PURPOSE

To compare the histologic prognostic feature of invasive breast cancer with mean stiffness as measured with shear-wave elastography.

MATERIALS AND METHODS

This retrospective study was exempted from ethical committee review. Patient consent for use of images for research was obtained. The study group comprised 101 consecutive women (age range, 38-91 years) with solid lesions identified during routine breast ultrasonography (US) performed between April 2010 and March 2011 and subsequently confirmed at histologic examination to be invasive cancers. Four elastographic images in two orthogonal planes were obtained of each lesion, and mean stiffness values were obtained from each image. Histologic findings following surgery were used for comparison, namely histologic grade, tumor type, invasive size, vascular invasion status, and lymph node status. Relationship between mean stiffness and histologic parameters was investigated by using a general linear model and multiple regression analysis.

RESULTS

High histologic grade (P < .0001), large invasive size (P < .0001), lymph node involvement (P < .0001), tumor type (P < .0001), and vascular invasion (P = .0077) all showed statistically significant positive association with high mean stiffness values. Multiple linear regression indicated that invasive size is the strongest pathologic determinant of mean stiffness (P < .0001), with histologic grade also having significant influence (P = .022).

CONCLUSION

In this study, breast cancers with higher mean stiffness values at shear-wave elastography had poorer prognostic features.

P5-21-03: The Breast Cancer Campaign Tissue Bank

The breast cancer research community has recognised that access to a source of carefully collected well-annotated human breast tissue is essential for translational research. Research institutions often face barriers in gaining access to this resource as collections typically have restrictive access policies or an over burdensome application process. This was formally recognised by around 50 prominent breast cancer researchers through a Gap Analysis conducted in London, UK in 20061. As a direct result of this report, 4 leading UK centres (Barts Cancer Institute, the Universities of Dundee, Leeds and Nottingham) with multi disciplinary expertise in pathology, basic science, bioinformatics and computer science have collaborated with a leading breast cancer charity to form the Breast Cancer Campaign Tissue Bank (BCCTB; http://www.breastcancercampaigntissuebank.org). BCCTB is a unique resource of biological materials and supportive clinical data, efficiently and ethically collected from patients with breast cancer, to provide researchers with high quality, relevant materials, helping to raise the standard of breast cancer research and facilitating the co-ordinated translation of scientific findings into the clinical setting. A wide range of biological materials are banked, including fresh frozen tumour and surrounding tissue, isolated purified cell populations (which can be provided for culture or DNA/RNA/protein extraction), whole blood and serum samples, as well as formalin-fixed paraffin-embedded material. Specialised collections are also available through the Bank on a collaborative basis. BCCTB has a centralised IT system allowing efficient tracking of samples and recording of raw data from studies, and providing a user-friendly web-based search portal to view material available. A purpose-built Bioinformatics platform allows mining breast cancer literature data from multiple sources and integrating different types of -omics and clinical data alongside publically relevant annotations from a growing number of biological resources such as NCBI, Ensembl, UniProt and Reactome. This platform is also fully interoperable with the International Cancer Genome Consortium (ICGC) and can be automatically cross-queried from the ICGC data portal which allows direct cross-comparison of experimental findings generated from the ICGC breast cancer projects with literature-derived information stored in our portal. Together this results in the highly efficient and co-ordinated use of samples, reducing duplication of effort and facilitating data mining and analysis. As science is constantly evolving we have an inbuilt R&D program, including cell immortalisation, investigating improved sample storage and collection methods and on-going IT development, all of which will ensure the bank remains cutting-edge. Tissue is released following review by a Tissue Access Committee comprising clinical and non-clinical breast cancer researchers and patient advocates. Direct interaction with end users ensures the materials and data supplied meets the researcher needs. Currently BCCTB is accepting applications from UK based researchers with projects funded by Breast Cancer Campaign. It will launch to the wider breast cancer community in the next 18 months.

1Thompson A et al., Breast Cancer Research 2008, 10:R26.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-21-03.

P3-12-04: Involved Anterior Margins after Breast Conserving Surgery: Is Re-Excision Required?

Background: Complete tumour excision in breast conserving surgery (BCS) is critical for successful treatment; involved circumferential resection margins are associated with increased disease recurrence. However, the importance of an involved anterior margin is less clear. The purpose of this study was to audit an aggressive approach to involved anterior margins and hence assess whether anterior margin re-excision yields clinical benefit.

Material and Methods: A retrospective case note and pathology review was performed for all patients who underwent BCS between 2006 and 2010 through a single cancer centre. An involved margin was defined as &lt;1mm clearance of invasive or in situ breast cancer. Results: 1667 patients underwent BCS for invasive and/or in-situ disease, of whom 114 (6.8%) underwent re-excision, most commonly for mixed invasive and in-situ pathology. The annual re-excision rate rose significantly (p&lt;0.001), with no change in whole tumour diameter, specimen weight or specimen volume. A total of 170 involved margins were identified: most commonly the anterior margin (59 margins, 30.6%) followed by the posterior (39 22.9%) or inferior (31, 18.3%) margin. Patients with anterior margin involvement were more likely to have grade 3 invasive disease (p=0.0323) but less likely to have residual disease found at re-excision (2/49 vs. 32/101 margins, p=0.0033); there were no differences when in-situ characteristics were compared.

Conclusions: Re-excision of involved anterior margins rarely excises residual disease and may be unnecessary. Multidisciplinary teams should consider whether further therapy for an involved anterior margin is required on a patient by patient basis.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-12-04.

Quantitative shear wave ultrasound elastography: initial experience in solid breast masses

INTRODUCTION

Shear wave elastography is a new method of obtaining quantitative tissue elasticity data during breast ultrasound examinations. The aims of this study were (1) to determine the reproducibility of shear wave elastography (2) to correlate the elasticity values of a series of solid breast masses with histological findings and (3) to compare shear wave elastography with greyscale ultrasound for benign/malignant classification.

METHODS

Using the Aixplorer® ultrasound system (SuperSonic Imagine, Aix en Provence, France), 53 solid breast lesions were identified in 52 consecutive patients. Two orthogonal elastography images were obtained of each lesion. Observers noted the mean elasticity values in regions of interest (ROI) placed over the stiffest areas on the two elastography images and a mean value was calculated for each lesion. A sub-set of 15 patients had two elastography images obtained by an additional operator. Reproducibility of observations was assessed between (1) two observers analysing the same pair of images and (2) findings from two pairs of images of the same lesion taken by two different operators. All lesions were subjected to percutaneous biopsy. Elastography measurements were correlated with histology results. After preliminary experience with 10 patients a mean elasticity cut off value of 50 kilopascals (kPa) was selected for benign/malignant differentiation. Greyscale images were classified according to the American College of Radiology (ACR) Breast Imaging Reporting and Data System (BI-RADS). BI-RADS categories 1-3 were taken as benign while BI-RADS categories 4 and 5 were classified as malignant.

RESULTS

Twenty-three benign lesions and 30 cancers were diagnosed on histology. Measurement of mean elasticity yielded an intraclass correlation coefficient of 0.99 for two observers assessing the same pairs of elastography images. Analysis of images taken by two independent operators gave an intraclass correlation coefficient of 0.80. Shear wave elastography versus greyscale BI-RADS performance figures were sensitivity: 97% vs 87%, specificity: 83% vs 78%, positive predictive value (PPV): 88% vs 84%, negative predictive value (NPV): 95% vs 82% and accuracy: 91% vs 83% respectively. These differences were not statistically significant.

CONCLUSIONS

Shear wave elastography gives quantitative and reproducible information on solid breast lesions with diagnostic accuracy at least as good as greyscale ultrasound with BI-RADS classification.

NF-kB Complex Activation and Association of αB-Crystallin and Vimentin with Poor Prognosis in Primary Breast Cancer

Background: Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) is a protein complex found in almost all animal cell types and is involved in cellular responses to stimuli such as stress, free radicals, cytokines et.c. NF-kB plays a key role in regulating the immune response and incorrect regulation of NF-kB has been linked to the development of cancer, several inflammatory and autoimmune diseases. The role of NF-kB, its subunits and pathways in breast cancer and in the surrounding stromal tissues remains uncertain. αB-crystallin is a heat shock protein, which function as stress-induced molecular chaperones to inhibit the aggregation of denatured proteins. Previous studies have identified αB-crystallin as a marker of poor prognosis for breast cancer and have suggested that it is an excellent marker for tumours of basal origin. The aim of this study is to examine, for the first time, NF-kB and αB-crystallin, vimentin and HSPs in the same set of breast cancers and stroma and relate this to clinical parameters including outcome.Methods: Tissue Micro Arrays of 0.6mm cores of 246 breast cancers were stained with antibodies to αB-crystallin, vimentin, HSP27 (antibody ERD5) and HSP27 82P and 12 subsequent antibodies for NF-kB (IKKa, Ser276, Ser32/36, 180/181, P52, 1kkygmma, P65, RELB, P100/P52, IkBa, cREL, and P50) and scored using the Quick Score Method.Results: Positive associations have been found between αB-crystallin and IKBA (P=0.001 Fishers exact test (FET)), RELB (P&lt;0.001 (FET)) and SER32/36 (P=0.03 (FET)) whereas Vimentin was positively associated IKBA (P=0.003 (FET)), IKKA (P=0.001 (FET)), P50 (P=0.002 (FET)), RELB (P&lt;0.001 (FET)) and SER32/36 (P=0.01 (FET)). Positive associations have also been found between HSP27 and P50 (P=0.002 (FET)), SER32/36 (P&lt;0.001 (FET)). Antibodies such as 180/181 (P=0.04 Kaplan Meier Log Rank (KM), cREL (P=0.03 (KM)), IKBA (P=0.03 (KM)) and IKKA (P=0.01 (KM)) was associated with good survival and P50 (P=0.002 (KM)) and P65 (P=0.01 (KM)) to poor survival. Expression of αB-crystallin was associated with vimentin (P&lt;0.001 (FET)). Its expression was linked to a low expression of the estrogen receptor. Vimentin expression was associated with estrogen receptor (ER) negative cancers and poor survival (P &lt;0.001 (FET)), P=0.002 (KM Log Rank) respectively). In contrast to αB-crystallin, low expression of HSP27 was associated with low ER and progesterone receptor (PGR).Conclusions: Associations were found between various antibodies within the NF-kB pathway as well as the heat shock proteins αB-crystallin, vimentin and HSP27 with varying implications for overall survival. We aim to clarify the mechanisms to prevent the aggregation of stress-accumulated misfolded proteins and apoptosis resulting better survival.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2143.

αB-crystallin, vimentin and increased p53 expression levels in breast cancer is associated with poor prognosis

Abstract #5070

Background: Previous studies have identified αB-crystallin as a marker of poor prognosis for breast cancer and have suggested that it is an excellent marker for tumours of basal origin. Increased expression of αB-crystallin has been associated with anchorage-independent growth and metastasis leading to the suggestion that αB-crystallin is an oncoprotein. We have considered whether the αB-crystallin binding proteins, vimentin and HSP27 also show a similar association with poor prognosis. We also investigated whether either HSP27 phosphorylation HSP27 or p53 expression could be associated with αB-crystallin expression.&#x2028; Methods: Tissue Micro Arrays of 0.6x0.6mm cores of 205 breast cancers were stained with antibodies to αB-crystallin, vimentin, p53 (antibodies DO1, FP3), HSP27 (antibody ERD5) and HSP27 82P. The levels of protein expressions were then compared with clinical and pathological parameters.&#x2028; Results: The expression of αB-crystallin was positively associated with vimentin (P&lt;0.001 Fisher's exact test (FET)). We have confirmed that αB-crystallin expression is linked to a low expression of the estrogen receptor and reduced survival (P&lt;0.001 (FET), P=0.002 Kaplan Meier Log Rank (KM) respectively). Vimentin expression was similarly associated with estrogen receptor (ER) negative cancers and poor survival (P &lt;0.001 (FET), P= 0.002 (KM Log Rank) respectively). Low expression of HSP27 resulted in poor three-year survival (P=0.007 (KM Log Rank)), but longer-term survival was unaffected (P=0.09 (KM Log Rank)). In contrast to αB-crystallin, low expression of HSP27 was associated with ER and progesterone receptor (PGR) negativity (P&lt;0.001 (FET), P=0.001 (FET)). HSP27 82P similarly resulted in poor three-year survival (P=0.01 (KM Log Rank)) compared with longer-term survival (P=0.05 (KM Log Rank)). In samples positive for either αB-crystallin or vimentin, a strong association with increased p53 expression (p53 antibodies: DO1(P&lt;0.001 (FET)) and FP3(P&lt;0.001 (FET))) was found.&#x2028; Conclusions: The increased expression of the protein chaperone, αB-crystallin was linked with reduced survival as well as it's binding partner, vimentin. We found that within this patient subgroup, there was an increased level of p53. The potential functional significance of this interaction for metastasis will be discussed in the context of other predictive markers for breast cancer. A similar association was not found for HSP27 expression.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5070.

A prognostic index for operable, node-negative breast cancer

Clinical data and samples from patients diagnosed, more than 10 years previously, with operable node-negative breast cancer (participants in the Scottish Adjuvant Tamoxifen trial), were revisited. Cases with two distinct categories of outcome were selected; more than 10 years disease-free survival ('good outcome') or distant relapse within 6 years of diagnosis ('poor outcome'). An initial set of cases was analysed for a range of putative prognostic markers and a prognostic index, distinguishing the two outcome categories, was calculated. This index was then validated by testing its predictive power on a second, independent set of cases. A combination of histological grade plus immunochemical staining for BCL-2, p27 and Cyclin D1, generated a useful prognostic index for tamoxifen-treated patients but not for those treated by surgery alone. The value of the index was confirmed in a second set of tamoxifen-treated, early stage breast cancers. Overall, it correctly predicted good and poor outcome in 79 and 74% of cases, respectively (odds ratio 11.0). Other markers assessed added little to prediction of outcome. In the case of molecular assays, sensitivity and reliability were compromised by the age of the tissue specimens and the variability of fixation protocols. In selecting patients for adjuvant systemic chemotherapy, the proposed index improves considerably on current international guidelines and matches the performance reported for 'gene-expression signature' analysis.