Tspan6 stimulates the chemoattractive potential of breast cancer cells for B cells in an EV- and LXR-dependent manner

The immune microenvironment in breast cancer (BCa) is controlled by a complex network of communication between various cell types. Here, we find that recruitment of B lymphocytes to BCa tissues is controlled via mechanisms associated with cancer cell-derived extracellular vesicles (CCD-EVs). Gene expression profiling identifies the Liver X receptor (LXR)-dependent transcriptional network as a key pathway that controls both CCD-EVs-induced migration of B cells and accumulation of B cells in BCa tissues. The increased accumulation oxysterol ligands for LXR (i.e., 25-hydroxycholesterol and 27-hydroxycholesterol) in CCD-EVs is regulated by the tetraspanin 6 (Tspan6). Tspan6 stimulates the chemoattractive potential of BCa cells for B cells in an EV- and LXR-dependent manner. These results demonstrate that tetraspanins control intercellular trafficking of oxysterols via CCD-EVs. Furthermore, tetraspanin-dependent changes in the oxysterol composition of CCD-EVs and the LXR signaling axis play a key role in specific changes in the tumor immune microenvironment.

Automated H&E whole slide image surrogate Ki67 index prediction and prognostic value across breast cancer subtypes

e12518

Background: Despite its purported prognostic significance in breast cancer, Ki67 index assessment remains poorly standardized and features high discordance rates amongst pathologists. Moreover, its clinical utility is presently confined to low stage, ER+/HER2- tumors in determining the advisability of adjuvant chemotherapy. Unfortunately, established cut-offs limit its utility to tumors with either high or low Ki67 index extremes. While Ki67 is a marker of actively dividing cells, it fails to capture the detail of cell cycle phase and dynamics which could be informative in terms of prognosis and tumor sensitivity to specific therapies (e.g. CDK4/6 inhibitors). This study therefore developed two novel indices as surrogates of (i) Ki67 index and (ii) quiescent cell population load (QPL). Methods: Breast cancer (comprising evenly distributed hormone receptor/HER2 status cases) H&E slides ( n = 79 cases/108 slides) were digitized on an Aperio DT3 scanner, and used to extract surrogate Ki67 and QPL indices. Sections were also stained for Ki67 by immunohistochemistry (IHC) using a clinically validated assay and digitized. Whole slide image (WSI) tumor Ki67 counts were performed on QuPath and used to validate the surrogate Ki67 index (Cohen’s kappa score). Indices (i) and (ii) were related to progression free survival (PFS). Survival analyses were performed using Kaplan-Meier (KM; with median cut-off) and Cox Proportional Hazards (as a continuous variable) models. Results: The surrogate Ki67 index showed good concordance with IHC scores (kappa = 0.76; 95%CI 0.61-0.91; P< 0.00001). However, this surrogate index performed better as a prognostic indicator of PFS compared to conventional Ki67 IHC (KM P = 0.048; HR = 1.35, P = 0.015 vs. KM P = 0.70; HR = 1.23, P = 0.08). Prognostically, the QPL index outperformed both Ki67 indices (KM P = 0.03; HR = 3.22, P = 0.001). Conclusions: We have developed two novel surrogate indices of Ki67 and QPL that can be readily automated to analyze H&E breast cancer WSIs. Our results show that both outperformed conventional Ki67 IHC evaluation in terms of prognostication, applied across molecular subtypes, improved informativeness of mid-range Ki67 index calls, and could potentially have predictive merit in selecting patients for cell cycle targeted therapies such as CDK4/6 inhibitors.

Combined Perioperative Lapatinib and Trastuzumab in Early HER2-Positive Breast Cancer Identifies Early Responders: Randomized UK EPHOS-B Trial Long-Term Results

PURPOSE

EPHOS-B aimed to determine whether perioperative anti-HER2 therapy inhibited proliferation and/or increased apoptosis in HER2-positive breast cancer.

PATIENTS AND METHODS

This randomized phase II, two-part, multicenter trial included newly diagnosed women with HER2-positive invasive breast cancer due to undergo surgery. Patients were randomized to: part 1 (1:2:2), no treatment (control), trastuzumab or lapatinib; part 2 (1:1:2) control, trastuzumab, or lapatinib and trastuzumab combination. Treatment was given for 11 days presurgery. Coprimary endpoints were change in Ki67 and apoptosis between baseline and surgery tumor samples (biologic response: ≥30% change). Central pathology review scored residual cancer burden (RCB). Relapse-free survival (RFS) explored long-term effects.

RESULTS

Between November 2010 and September 2015, 257 patients were randomized (part 1: control 22, trastuzumab 57, lapatinib 51; part 2: control 29, trastuzumab 32, combination 66). Ki67 response was evaluable for 223 patients: in part 1 Ki67 response occurred in 29/44 (66%) lapatinib versus 18/49 (37%) trastuzumab (P = 0.007) and 1/22 (5%) control (P < 0.0001); in part 2 in 36/49 (74%) combination versus 14/31 (45%) trastuzumab (P = 0.02) and 2/28 (7%) control (P < 0.0001). No significant increase in apoptosis after 11 days was seen in treatment groups. Six patients achieved complete pathologic response (pCR, RCB0) and 13 RCB1, all but two in the combination group. After 6 years median follow-up, 28 (11%) had recurrence and 19 (7%) died. No recurrences or deaths were observed among patients who achieved a pCR. Ki67% falls ≥50% associated with fewer recurrences (P = 0.002).

CONCLUSIONS

Early response after short duration anti-HER2 dual therapy identifies cancers dependent on the HER2 pathway providing a strategy for exploring risk-adapted individualized treatment de-escalation.

Abstract P2-13-08: Combined peri-operative lapatinib and trastuzumab in early HER2-positive breast cancer - Long term results of the randomized UK EPHOS-B trial

Background: EPHOS-B is a multi-centre randomized trial designed to investigate whether anti-HER2 therapy given 11 days pre-surgery inhibited proliferation and/or increased apoptosis in HER2-positive early breast cancer. Significant differences in Ki67 response (≥30% change between baseline and surgery) were observed between treatment groups and control, although no significant increases in apoptosis were seen [1]. We report here 5-year outcomes and their association with peri-operative response, including post-hoc exploratory analyses on stromal tumour infiltrating lymphocytes (TILs). Methods: Patients were randomized (1:2:2) to no treatment (control), trastuzumab or lapatinib (Part-1), and (1:1:2) to control, trastuzumab, or lapatinib and trastuzumab combination (Part-2). Relapse free survival (RFS) is defined as the time from randomisation to local, regional, or distant tumour recurrence or death from any cause, with second primary cancers censored. Five-year RFS rates were estimated by Kaplan-Meier across treatment and peri-operative response groups, and compared by Log-Rank tests. Central scoring of stromal tumour infiltrating lymphocytes (TILs) on scanned H&E baseline and surgery slides was conducted post-hoc according to the International TILs Working Group. Baseline TILs (bTILS) were explored across treatment groups, and associated with trial outcomes. Changes in TILS in patients without pathological regression were correlated with Ki67 changes and RFS. Results: Overall, 257 patients were randomized (Part-1: control 22, trastuzumab 57, lapatinib 51; Part-2: control 29, trastuzumab 32, trastuzumab+lapatinib 66). Central pathology review identified six patients achieving complete pathological response (pCR), and 13 RCB1 (as per the Residual Cancer Burden score), all but two in the combination group. After 6 years median follow-up, 28 women (11%) had recurrence, and 19 (7%) died; no differences between groups were found (Table). No recurrences were observed amongst pCR patients; only 1 local recurrence observed amongst RCB1. Patients with Ki67 falls ≥50% had better RFS than those with modest falls or no falls (Table). In patients with no evidence of disease regression at surgery, those with higher TILs (≥20%) at surgery had better RFS than those with lower TILs.

Conclusions: Early response (pCR/RCB1 or Ki67 reductions &gt;50%) after 11 days pre-operative anti-HER2 dual therapy identifies cancers dependent on the HER2 pathway and provides a strategy for individualising treatment, including de-escalation of therapy. [1] Bundred N, Cameron D, Amstrong A et al (2016) Effects of perioperative lapatinib and trastuzumab, alone and in combination, in early HER2+ breast cancer − the UK EPHOS-B trial (CRUK/08/002) European Journal of Cancer;57:S1-S8.

Table - Relapse-free survival by treatment and by peri-operative responseN randomisedNRFS event5-year RFS95%CILog-rank p-valueRandomised treatmentTrastuzumab (P1)577 (12.3%)88%76-94%T vs L p=0.75Lapatinib (P1)515 (9.8%)90%77-96%L vs C p=0.41Control (P1)221 (4.6%)95%92-99%Trastuzumab (P2)327 (21.9%)87%69-95%T vs T+L p=0.048Combination (P2)665 (7.6%)92%83-97%T+L vs C p=0.64Control (P2)293 (10.3%)90%71-97%%Ki67 change:&gt;50% decrease722 (2.8%)99%90-100%0.002&gt;10% decrease7717 (22.1%)80%69-88%&lt;10% or no decrease827 (8.5%)91%83-96%Disease responseRCB060100%-0.63RCB1131 (7.7%)92%57-99RCB2/3/no evidence of regression23626 (11%)90%85-93Baseline TILS&lt;=20%18023 (13%)89%83-930.10&gt;20%502 (4%)96%85-99Surgery TILS (only RCB2/3)&lt;=20%12220 (16.4%)86%78-910.021&gt;20%653 (4.6%)95%86-98Change in TILS (only RCB2/3)No significant increase15221 (13.8%)88%81-920.16Increase &gt;20%352 (5.7%)94%79-99

Citation Format: Nigel Bundred, Nuria Porta, Adrian Murray Brunt, Angela Cramer, Andrew Hanby, Abeer Shaaban, Emad Rakha, Anne Armstrong, Ramsey Cutress, David Dodwell, Marie Emson, Abigail Evans, Sue Hartup, Kieran Horgan, Stuart McIntosh, Jay Naik, Samkaran Narayanan, Jane Oii, Anthony Skene, David Cameron, Judith Bliss. Combined peri-operative lapatinib and trastuzumab in early HER2-positive breast cancer - Long term results of the randomized UK EPHOS-B trial [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 P2-13-08.

Digital pathology for primary diagnosis of screen-detected breast lesions - experimental data, validation and experience from four centres

AIM

The rate of deployment of digital pathology (DP) systems for primary diagnosis in the UK is accelerating. The flexibility and resilience of digital versus standard glass slides could be of great benefit in the NHS breast screening programme (NHSBSP). This study aims to document the safety and benefits of DP for preoperative tissue diagnosis of screen-detected breast lesions.

METHODS AND RESULTS

Concordance data for glass and digital slides of the same cases from four sites were subjected to detailed concordance-discordance analysis. A literature review of DP in the primary diagnosis of breast lesions is presented, making this the most comprehensive synthesis of digital breast cancer histopathological diagnostic data to date. Detailed concordance analysis of experimental data from two histopathology departments reveals clinical concordance rates for breast biopsies of 96% (216 of 225) and 99.6% (249 of 250). Data from direct comparison validation studies in two histopathology departments, utilising the protocol recommended by the Royal College of Pathologists, found concordance rates for breast histology cases of 99.4% (180 of 181) and 99.0% (887 of 896). An intraobserver variation study for glass versus digital slides for difficult cases from the NHSBSP yielded a kappa statistic of 0.80, indicating excellent agreement. Discordances encountered in the studies most frequently concerned discrepancies in grading attributable to mitotic count-scoring and identification of weddelite.

CONCLUSIONS

The experience of four histopathology laboratories and our review of pre-existing literature suggests that DP is safe for the primary diagnosis of NHSBSP breast histology specimens, and does not increase the risk of misclassification.

The CD151-midkine pathway regulates the immune microenvironment in inflammatory breast cancer

The immune microenvironment in inflammatory breast cancer (IBC) is poorly characterised, and molecular and cellular pathways that control accumulation of various immune cells in IBC tissues remain largely unknown. Here, we discovered a novel pathway linking the expression of the tetraspanin protein CD151 in tumour cells with increased accumulation of macrophages in cancerous tissues. It is notable that elevated expression of CD151 and a higher number of tumour-infiltrating macrophages correlated with better patient responses to chemotherapy. Accordingly, CD151-expressing IBC xenografts were characterised by the increased infiltration of macrophages. In vitro migration experiments demonstrated that CD151 stimulates the chemoattractive potential of IBC cells for monocytes via mechanisms involving midkine (a heparin-binding growth factor), integrin α6β1, and production of extracellular vesicles (EVs). Profiling of chemokines secreted by IBC cells demonstrated that CD151 increases production of midkine. Purified midkine specifically stimulated migration of monocytes, but not other immune cells. Further experiments demonstrated that the chemoattractive potential of IBC-derived EVs is blocked by anti-midkine antibodies. These results demonstrate for the first time that changes in the expression of a tetraspanin protein by tumour cells can affect the formation of the immune microenvironment by modulating recruitment of effector cells to cancerous tissues. Therefore, a CD151-midkine pathway can be considered as a novel target for controlled changes of the immune landscape in IBC. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Associations Between Serum Bone Biomarkers in Early Breast Cancer and Development of Bone Metastasis: Results From the AZURE (BIG01/04) Trial

Background

Adjuvant therapies can prevent/delay bone metastasis development in breast cancer. We investigated whether serum bone turnover markers in early disease have clinical utility in identifying patients with a high risk of developing bone metastasis.

Methods

Markers of bone formation (N-terminal propeptide of type-1 collagen [P1NP]) and bone resorption (C-telopeptide of type-1 collagen [CTX], pyridinoline cross-linked carboxy-terminal telopeptide of type-1 collagen [1-CTP]) were measured in baseline (pretreatment blood samples from 872 patients from a large randomized trial of adjuvant zoledronic acid (AZURE-ISRCTN79831382) in early breast cancer. Cox proportional hazards regression and cumulative incidence functions (adjusted for factors having a statistically significant effect on outcome) were used to investigate prognostic and predictive associations between recurrence events, bone marker levels, and clinical variables. All statistical tests were two-sided.

Results

When considered as continuous variables (log transformed), P1NP, CTX, and 1-CTP were each prognostic for future bone recurrence at any time (P = .006, P = .009, P = .008, respectively). Harrell’s c-indices were a P1NP of 0.57 (95% confidence interval [CI] = 0.51 to 0.63), CTX of 0.57 (95% CI = 0.51 to 0.62), and 1-CTP of 0.57 (95% CI = 0.52 to 0.63). In categorical analyses based on the normal range, high baseline P1NP (>70 ng/mL) and CTX (>0.299 ng/mL), but not 1-CTP (>4.2 ng/mL), were also prognostic for future bone recurrence (P = .03, P = .03, P = .10, respectively). None of the markers were prognostic for overall distant recurrence; that is, they were bone metastasis specific, and none of the markers were predictive of treatment benefit from zoledronic acid.

Conclusions

Serum P1NP, CTX, and 1-CTP are clinically useful, easily measured markers that show good prognostic ability (though low-to-moderate discrimination) for bone-specific recurrence and are worthy of further study.

Abstract P3-06-19: MUC17 and PCNX1 as mediators of chemotherapy response in breast cancer

Breast cancer is a heterogeneous disease and accumulating evidence suggests that treatment failure may be driven by intra-tumour heterogeneity (ITH). Utilising the current protocol for neoadjuvant (pre-surgery) chemotherapy (NAC) provides the opportunity to study molecular genetic changes between pre- and post-therapy by assessing pre-therapy biopsies and post-therapy surgical resections.

Whole exome sequencing was performed on matched pre- and post-treatment cancer cells from 6 patients with oestrogen receptor positive breast cancers that showed partial responses to the chemotherapeutic epirubicin. Data analysis was performed to determine differences in genetic aberrations between pre- and post-NAC, and in particular to identify evidence of consistent selection by therapy of aberrations that therefore may define chemotherapy resistance or sensitivity.

There were extensive differences in the range of genetic aberrations between pre- and post-NAC. 48 genes were identified for further study based on evidence of mutations conferring a selective advantage or disadvantage during chemotherapeutic response. The relevance of these was screened using siRNA knock-down and assessment of response to chemotherapeutic drug using cell viability assays in vitro. Two genes were taken forward. Potential loss-of-function mutations in the MUC17 gene were selected against during therapy in patients, and in accordance with this MUC17 knock-down was associated with increased sensitivity in vitro. Potential loss-of-function mutations in the PCNX1 gene were selected for during therapy in patients, and in accordance with this PCNX1 knock-down was associated with resistance. Further work was done to investigate mechanisms by which these genes modify cellular chemotherapy response, by examining drug loading and ABC transporter expression levels. Data indicate that both genes impact on drug loading, potentially through modulating ABC transporter activities. Using available transcriptomic datasets, expression of neither gene correlated with breast cancer outcomes in mixed cohorts that received a wide-range of therapies, however, analysis of correlations between protein expression and outcomes specifically after chemotherapy are on-going. We conclude that MUC17 and PCNX1 are potential markers of response to chemotherapy in breast cancer, and therapeutic modulation of their activities could enhance chemotherapy responses.

Citation Format: Al Amri W, Verghese E, Stead L, Hanby A, Sharma N, Hughes T. MUC17 and PCNX1 as mediators of chemotherapy response in breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-06-19.

Management and 5-year outcomes in 9938 women with screen-detected ductal carcinoma in situ: the UK Sloane Project

BACKGROUND

Management of screen-detected ductal carcinoma in situ (DCIS) remains controversial.

METHODS

A prospective cohort of patients with DCIS diagnosed through the UK National Health Service Breast Screening Programme (1st April 2003 to 31st March 2012) was linked to national databases and case note review to analyse patterns of care, recurrence and mortality.

RESULTS

Screen-detected DCIS in 9938 women, with mean age of 60 years (range 46-87), was treated by mastectomy (2931) or breast conserving surgery (BCS) (7007; 70%). At 64 months median follow-up, 697 (6.8%) had further DCIS or invasive breast cancer after BCS (7.8%) or mastectomy (4.5%) (p < 0.001). Breast radiotherapy (RT) after BCS (4363/7007; 62.3%) was associated with a 3.1% absolute reduction in ipsilateral recurrent DCIS or invasive breast cancer (no RT: 7.2% versus RT: 4.1% [p < 0.001]) and a 1.9% absolute reduction for ipsilateral invasive breast recurrence (no RT: 3.8% versus RT: 1.9% [p < 0.001]), independent of the excision margin width or size of DCIS. Women without RT after BCS had more ipsilateral breast recurrences (p < 0.001) when the radial excision margin was <2 mm. Adjuvant endocrine therapy (1208/9938; 12%) was associated with a reduction in any ipsilateral recurrence, whether RT was received (hazard ratio [HR] 0.57; 95% confidence interval [CI] 0.41-0.80) or not (HR 0.68; 95% CI 0.51-0.91) after BCS. Women who developed invasive breast recurrence had a worse survival than those with recurrent DCIS (p < 0.001). Among 321 (3.2%) who died, only 46 deaths were attributed to invasive breast cancer.

CONCLUSION

Recurrent DCIS or invasive cancer is uncommon after screen-detected DCIS. Both RT and endocrine therapy were associated with a reduction in further events but not with breast cancer mortality within 5 years of diagnosis. Further research to identify biomarkers of recurrence risk, particularly as invasive disease, is indicated.

Harnessing citizen science through mobile phone technology to screen for immunohistochemical biomarkers in bladder cancer

BACKGROUND

Immunohistochemistry (IHC) is often used in personalisation of cancer treatments. Analysis of large data sets to uncover predictive biomarkers by specialists can be enormously time-consuming. Here we investigated crowdsourcing as a means of reliably analysing immunostained cancer samples to discover biomarkers predictive of cancer survival.

METHODS

We crowdsourced the analysis of bladder cancer TMA core samples through the smartphone app 'Reverse the Odds'. Scores from members of the public were pooled and compared to a gold standard set scored by appropriate specialists. We also used crowdsourced scores to assess associations with disease-specific survival.

RESULTS

Data were collected over 721 days, with 4,744,339 classifications performed. The average time per classification was approximately 15 s, with approximately 20,000 h total non-gaming time contributed. The correlation between crowdsourced and expert H-scores (staining intensity × proportion) varied from 0.65 to 0.92 across the markers tested, with six of 10 correlation coefficients at least 0.80. At least two markers (MRE11 and CK20) were significantly associated with survival in patients with bladder cancer, and a further three markers showed results warranting expert follow-up.

CONCLUSIONS

Crowdsourcing through a smartphone app has the potential to accurately screen IHC data and greatly increase the speed of biomarker discovery.

Germline BRCA mutation and outcome in young-onset breast cancer (POSH): a prospective cohort study

BACKGROUND

Retrospective studies provide conflicting interpretations of the effect of inherited genetic factors on the prognosis of patients with breast cancer. The primary aim of this study was to determine the effect of a germline BRCA1 or BRCA2 mutation on breast cancer outcomes in patients with young-onset breast cancer.

METHODS

We did a prospective cohort study of female patients recruited from 127 hospitals in the UK aged 40 years or younger at first diagnosis (by histological confirmation) of invasive breast cancer. Patients with a previous invasive malignancy (except non-melanomatous skin cancer) were excluded. Patients were identified within 12 months of initial diagnosis. BRCA1 and BRCA2 mutations were identified using blood DNA collected at recruitment. Clinicopathological data, and data regarding treatment and long-term outcomes, including date and site of disease recurrence, were collected from routine medical records at 6 months, 12 months, and then annually until death or loss to follow-up. The primary outcome was overall survival for all BRCA1 or BRCA2 mutation carriers (BRCA-positive) versus all non-carriers (BRCA-negative) at 2 years, 5 years, and 10 years after diagnosis. A prespecified subgroup analysis of overall survival was done in patients with triple-negative breast cancer. Recruitment was completed in 2008, and long-term follow-up is continuing.

FINDINGS

Between Jan 24, 2000, and Jan 24, 2008, we recruited 2733 women. Genotyping detected a pathogenic BRCA mutation in 338 (12%) patients (201 with BRCA1, 137 with BRCA2). After a median follow-up of 8·2 years (IQR 6·0-9·9), 651 (96%) of 678 deaths were due to breast cancer. There was no significant difference in overall survival between BRCA-positive and BRCA-negative patients in multivariable analyses at any timepoint (at 2 years: 97·0% [95% CI 94·5-98·4] vs 96·6% [95·8-97·3]; at 5 years: 83·8% [79·3-87·5] vs 85·0% [83·5-86·4]; at 10 years: 73·4% [67·4-78·5] vs 70·1% [67·7-72·3]; hazard ratio [HR] 0·96 [95% CI 0·76-1·22]; p=0·76). Of 558 patients with triple-negative breast cancer, BRCA mutation carriers had better overall survival than non-carriers at 2 years (95% [95% CI 89-97] vs 91% [88-94]; HR 0·59 [95% CI 0·35-0·99]; p=0·047) but not 5 years (81% [73-87] vs 74% [70-78]; HR 1·13 [0·70-1·84]; p=0·62) or 10 years (72% [62-80] vs 69% [63-74]; HR 2·12 [0·82-5·49]; p= 0·12).

INTERPRETATION

Patients with young-onset breast cancer who carry a BRCA mutation have similar survival as non-carriers. However, BRCA mutation carriers with triple-negative breast cancer might have a survival advantage during the first few years after diagnosis compared with non-carriers. Decisions about timing of additional surgery aimed at reducing future second primary-cancer risks should take into account patient prognosis associated with the first malignancy and patient preferences.

FUNDING

Cancer Research UK, the UK National Cancer Research Network, the Wessex Cancer Trust, Breast Cancer Now, and the PPP Healthcare Medical Trust Grant.

MED12, TERT promoter and RBM15 mutations in primary and recurrent phyllodes tumours

BACKGROUND

MED12 and TERT promoter mutations have been shown to be the most common somatic mutations in phyllodes tumours (PTs). The aims of this study were to determine the frequency of these mutations in recurrent PTs, assess whether TERT promoter mutations could be helpful in distinguishing fibroadenomas (FAs) from PTs and identify novel mutations that may be driving malignant progression.

METHODS

MED12 and the TERT promoter were Sanger sequenced in 75 primary PTs, 21 recurrences, 19 single FAs and 2 cases of multiple FAs with benign PTs. Whole-exome sequencing was performed on one borderline PT.

RESULTS

Recurrent PTs and multiple FAs showed temporal discordance in MED12 but not TERT. Recurrent samples did acquire TERT mutations, with recurrent benign PTs more likely to have mutations in both genes. TERT mutations were not helpful in differentiating between benign PTs and FAs in cases of multiple FAs/PTs. Exome sequencing revealed a nonsense mutation in RBM15 and Sanger sequencing revealed another three RBM15 mutations in malignant/borderline PTs.

CONCLUSIONS

This study has shown that MED12 mutations can be heterogeneous in both synchronous and recurrent PTs unlike TERT mutations. We have also shown that RBM15 mutations may be important in the pathogenesis of borderline/malignant PTs.

Digital pathology for the primary diagnosis of breast histopathological specimens: an innovative validation and concordance study on digital pathology validation and training

AIM

To train and individually validate a group of breast pathologists in specialty-specific digital primary diagnosis by using a novel protocol endorsed by the Royal College of Pathologists' new guideline for digital pathology. The protocol allows early exposure to live digital reporting, in a risk-mitigated environment, and focuses on patient safety and professional development.

METHODS AND RESULTS

Three specialty breast pathologists completed training in the use of a digital microscopy system, and were exposed to a training set of 20 challenging cases, designed to help them identify personal digital diagnostic pitfalls. Following this, the three pathologists viewed a total of 694 live, entire breast cases. All primary diagnoses were made on digital slides, with immediate glass slide review and reconciliation before final case sign-out. There was complete clinical concordance between the glass and digital impression of the case in 98.8% of cases. Only 1.2% of cases had a clinically significant difference in diagnosis/prognosis on glass and digital slide reads. All pathologists elected to continue using the digital microscope as the standard for breast histopathology specimens, with deferral to glass for a limited number of clinical/histological scenarios as a safety net.

CONCLUSION

Individual training and validation for digital primary diagnosis allows pathologists to develop competence and confidence in their digital diagnostic skills, and aids safe and responsible transition from the light microscope to the digital microscope.

Effect of MAF amplification on treatment outcomes with adjuvant zoledronic acid in early breast cancer: a secondary analysis of the international, open-label, randomised, controlled, phase 3 AZURE (BIG 01/04) trial

BACKGROUND

Adjuvant use of bisphosphonates can reduce the incidence of bone metastases in early breast cancer. Recurrence and survival seem to be improved only in postmenopausal patients, but the underlying mechanisms remain unclear. We investigated whether MAF amplification (a biomarker for bone metastasis) in primary tumours could predict the treatment outcomes of adjuvant zoledronic acid.

METHODS

The study population included patients enrolled in the international, open-label, randomised, controlled, phase 3 AZURE trial at eligible UK sites who had stage II or III breast cancer and who gave consent for use of their primary tumour samples. Patients were randomly assigned (1:1) to receive standard adjuvant systemic therapy alone (control group) or with zoledronic acid every 3-4 weeks for six doses, then every 3-6 months until the end of 5 years. Minimisation took into account the number of involved axillary lymph nodes, clinical tumour stage, oestrogen-receptor status, type and timing of systemic therapy, menopausal status, statin use, and treating centre. The primary endpoint was disease-free survival; the secondary endpoint, invasive-disease-free survival, was the primary disease endpoint for the analysis in this report. MAF amplification was assessed by fluorescence in-situ hybridisation of two cores of breast tumour tissue in a microarray, done in a central laboratory by technicians unaware of treatment assignment. We used multivariate analyses to assess disease outcomes by intention to treat. We also assessed interactions between MAF-positive status and menopausal status on efficacy of zoledronic acid. The AZURE trial is registered with the International Standard Randomised Controlled Trial Registry, number ISRCTN79831382.

FINDINGS

1739 AZURE patients contributed primary tumour samples, of whom 865 (50%) had two assessable cores (445 in the control groups and 420 in the zoledronic acid group). 184 (21%) tumours were MAF positive (85 in the control groups and 99 in the zoledronic acid group) and the remaining tumours were MAF negative. At a median follow-up of 84·6 months (IQR 72·0-95·8), MAF status was not prognostic for invasive-disease-free survival in the control group (MAF-positive vs MAF-negative: hazard ratio [HR] 0·92, 95% CI 0·59-1·41), but was in the zoledronic acid group (0·52, 0·36-0·75). In patients with MAF-negative tumours, zoledronic acid was associated with higher invasive-disease-free survival than was control treatment (HR 0·74, 95% CI 0·56-0·98), but not in patients who had MAF-positive tumours. Additionally, among 121 patients not postmenopausal at randomisation with MAF-positive tumours, zoledronic acid was associated with lower invasive-disease-free survival (HR 2·47, 95% CI 1·23-4·97) and overall survival (2·27, 95% CI 1·04-4·93) than control treatment.

INTERPRETATION

MAF status can predict likelihood of benefit from adjuvant zoledronic acid and merits further investigation as a potential companion diagnostic.

FUNDING

Novartis Global and Inbiomotion.

Abstract P3-17-06: LORIS trial of active monitoring for DCIS: How does the online pathology eligibility review process work?

Introduction

The LORIS Trial is a UK randomized clinical trial comparing active monitoring with surgery for low risk ductal carcinoma in situ (DCIS), defined as low or low-intermediate grade DCIS without comedo necrosis, as diagnosed on vacuum-assisted (wide bore) core needle samples. Because of the inconsistency of grading DCIS, we have underpinned this trial with a Central Histopathology Review (CHR) before randomisation. The process of the CHR for the first 22 months of a two year pilot study between July 2014 and May 2016 is reported here.

Patients and methods

Patients were eligible for CHR if they satisfied all of the eligibility criteria and had locally reported low or intermediate grade DCIS. Patients were identified at 28 pilot sites and were registered for potential trial entry following written informed consent before being subjected to CHR. CHR comprised online examination of digitally scanned histology slides of all material from all diagnostic biopsies and was performed by at least two of the three LORIS specialist breast pathologists. Histology slides were submitted using Royal Mail Safebox® to the University of Birmingham where they were digitally scanned and made available for review via the Leica digital image hub. The outcome of the review was reported in a separate secure online database by completion of a Central Pathology Review Form. Access to both online systems is password protected. Eligibility was confirmed if two pathologists agreed that there was low or low to intermediate grade DCIS and no comedo necrosis. A maximum of 7 calendar days from receipt of the diagnostic material was allowed for the central review process.

The digital images of the histology slides are stored by the Leica system for future reference.

Results

100 patients were registered and their slides reviewed. 55 of these were deemed eligible by CHR; of these 38 have been randomised. 45 patients were deemed ineligible, most commonly due to grade being in the upper half of the intermediate category and/or comedo necrosis. In addition, 9 patients were deemed not to have DCIS and 1 patient had invasive disease.

Grouping the grade categories as low and low to intermediate grade (low risk and eligible for randomisation) Vs intermediate to high and high cytonuclear grade (ineligible for randomisation) showed 91% agreement on grade category amongst the reviewing pathologists.

Results of the central review were made available to sites within 7 days for 97% of cases submitted. On average, central review was completed within 4 days. Average time between registration and randomisation was 3 weeks. The LORIS central review pathologists found online viewing and reporting of sections acceptable.

Conclusions

Central Histopathology Review using online viewing of digital slides provides timely and efficient pathology Quality Assurance in this clinical trial setting, with acceptable turnaround times and good agreement between reviewing specialist breast pathologists. This process will be continued in the main phase of the trial.

Citation Format: Thomas J, Hanby A, Pinder S, Pirrie S, Rea D, Gaunt C, Young J, Francis A. LORIS trial of active monitoring for DCIS: How does the online pathology eligibility review process work? [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-17-06.

Abstract OT1-03-01: The UK LORIS trial: Randomizing patients with low or low intermediate grade ductal carcinoma in situ (DCIS) to surgery or active monitoring

Background: The independent review of the UK National Health Service Breast Screening Programme reported (The Lancet, Volume 380, Issue 9855, Page 1778, 17 Nov 2012) on the benefits and harms of breast screening. It concluded that breast screening saves lives and acknowledged the existence of overtreatment. It encouraged randomized trials to elucidate the appropriate treatment of screen-detected DCIS to gain a better understanding of its natural history. The LORIS trial addresses the possible overtreatment of low and low/intermediate grade screen-detected (low risk) DCIS by randomizing patients to standard surgical treatment or active monitoring, each with long term follow up.

Trial Design: LORIS is a phase III, multicentre, 2 arm study, with a built in 2 year Feasibility Phase, in patients confirmed to have low risk DCIS defined by strict criteria and determined by central pathology review. Patients will be randomized between standard surgery and active monitoring with annual mammography. Patients will be followed up for a minimum of 10 years.

Eligibility Criteria:

1) Female, age ≥ 46 years

2) Screen-detected or incidental microcalcification (with no mass lesion clinically or on imaging)

3) Low risk DCIS on large volume vacuum-assisted biopsy, confirmed by central pathology review

4) Patient fit to undergo surgery

5) No previous breast cancer or ipsilateral DCIS diagnosis

6) Written informed consent

Specific Aims: The LORIS Trial aims to establish whether patients with newly diagnosed low risk DCIS can safely avoid surgery without detriment to their wellbeing (psychological and physical) and whether those patients that do require surgery can be identified by pathological and radiological means.

Primary endpoint: Ipsilateral invasive breast cancer free survival time

Secondary endpoints: Overall survival; mastectomy rate; time to mastectomy; time to surgery; patient reported outcomes; health resource utilisation and assessment of predictive biomarkers.

A digital image data repository and tissue bank will provide a prospective resource for both translational and imaging studies.

Statistical Methods: A total of 932 patients will be randomized to a non-inferiority design to test the null hypothesis that active monitoring of women diagnosed with low risk DCIS is not non-inferior in terms of ipsilateral invasive breast cancer free survival (iiBCFS) time compared to treatment with surgery. The iiBCFS time will be compared across the two arms on a per protocol and intent-to-treat basis, using a 1-sided (α=0.05) log-rank test for non-inferiority. The iiBCFS rate is assumed to be 97.5% in the surgery arm at 5 years, utilizing 80% power to exclude a difference of more than 2.5% in the active monitoring arm.

Present Accrual and Target Accrual: 32 UK centres are open for the Feasibility Phase of the trial which is nearing completion. The web-based central pathology review process is functioning efficiently, with a one week maximum turn around. Registrations and sites randomizing patients are on or above target. Randomizations are currently approximately 70% of target. A total of 60 centres will open in the main trial.

Contact Information: For further information, please email the LORIS Trial Office LORIS@trials.bham.ac.uk.

Citation Format: Francis A, Bartlett J, Billingham L, Bowden S, Brookes C, Dodwell D, Evans A, Fairbrother P, Fallowfield L, Gaunt C, Hanby A, Jenkins V, Matthews L, Pinder S, Pirrie S, Rea D, Reed M, Roberts T, Thomas J, Wallis M, Wilcox M, Young J. The UK LORIS trial: Randomizing patients with low or low intermediate grade ductal carcinoma in situ (DCIS) to surgery or active monitoring [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT1-03-01.

Abstract OT2-02-04: The LORIS trial: A multicentre, randomised phase III trial of standard surgery versus active monitoring in women with newly diagnosed low risk ductal carcinoma in situ

Background: The independent review of the UK National Health Service Breast Screening Programme reported (The Lancet, Volume 380, Issue 9855, Pages 1778 - 1786, 17 November 2012) on the benefits & harms of breast screening. It concluded that breast screening saves lives & acknowledged overtreatment. It encouraged randomized trials to elucidate the appropriate treatment of screen-detected ductal carcinoma in situ (DCIS) to gain a better understanding of its natural history. The LORIS trial addresses overtreatment of low & low/Intermediate grade screen detected (low risk) DCIS by randomizing patients to standard surgical treatment or active monitoring.

Trial Design: LORIS is a phase III, multicentre, 2 arm study, with a 2 year feasibility phase, in patients confirmed to have low risk DCIS by central pathology review. Patients are randomised to standard surgery or active monitoring with annual mammography. Patients will be followed up for a minimum of 10 years.

Key Eligibility Criteria:

1) Female 46 years or over.

2) Screen-detected or incidental microcalcification (with no mass lesion clinically or on imaging)

3) Low risk DCIS on large volume vacuum-assisted biopsy, confirmed by central pathology review

4) Patient fit to undergo surgery

Specific Aims: The LORIS Trial aims to establish whether patients with newly diagnosed low risk DCIS can safely avoid surgery without detriment to their wellbeing (psychological and physical) & whether those patients that do require surgery can be identified by pathological and radiological means.

Primary endpoint: Ipsilateral invasive breast cancer free survival rate at 5 years

Secondary endpoints: Overall survival; mastectomy rate; time to mastectomy; time to surgery; patient reported outcomes & health resource utilisation.

A digital image data repository and tissue bank provide a prospective resource for both translational & imaging studies.

Statistical Methods: A total of 932 patients will be randomized to a non-inferiority design to test the null hypothesis that active monitoring of women diagnosed with low risk DCIS is not non-inferior in terms of 5 year ipsilateral invasive breast cancer free survival (iiBCFS) rate compared to treatment with surgery. The iiBCFS rate will be compared across the two arms on a per protocol and intent-to-treat basis, using a 1-sided (α=0.05) log-rank test for non-inferiority. The iiBCFS rate is assumed to be 97.5% in the surgery arm giving 80% power to exclude a difference of more than 2.5% in the active monitoring arm at 5 years.

Present Accrual and Target Accrual: 21 UK centres are open & the feasibility phase of the trial is recruiting to target. The web based central pathology review process is functioning well with a one week maximum turn around. A further 40 centres will be opened on completion of the feasibility phase.

Contact: LORIS@trials.bham.ac.uk

This project was funded by the National Institute for Health Research [Health Technology Assessment Programme] (project number 11/36/16)

Department of Health Disclaimer: The views & opinions expressed therein are those of the authors & do not necessarily reflect those of the Health Technology Assessment Programme, NIHR, NHS or the Department of Health.

Citation Format: Francis A, Fallowfield L, Bartlett J, Thomas J, Wallis M, Hanby A, Pinder S, Evans A, Billingham L, Brookes C, Dodwell D, Fairbrother P, Gaunt C, Jenkins V, Matthews L, Pirrie S, Reed M, Roberts T, Wilcox M, Young J, Rea D. The LORIS trial: A multicentre, randomised phase III trial of standard surgery versus active monitoring in women with newly diagnosed low risk ductal carcinoma in situ. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT2-02-04.

Crowdsourcing the General Public for Large Scale Molecular Pathology Studies in Cancer

BACKGROUND

Citizen science, scientific research conducted by non-specialists, has the potential to facilitate biomedical research using available large-scale data, however validating the results is challenging. The Cell Slider is a citizen science project that intends to share images from tumors with the general public, enabling them to score tumor markers independently through an internet-based interface.

METHODS

From October 2012 to June 2014, 98,293 Citizen Scientists accessed the Cell Slider web page and scored 180,172 sub-images derived from images of 12,326 tissue microarray cores labeled for estrogen receptor (ER). We evaluated the accuracy of Citizen Scientist's ER classification, and the association between ER status and prognosis by comparing their test performance against trained pathologists.

FINDINGS

The area under ROC curve was 0.95 (95% CI 0.94 to 0.96) for cancer cell identification and 0.97 (95% CI 0.96 to 0.97) for ER status. ER positive tumors scored by Citizen Scientists were associated with survival in a similar way to that scored by trained pathologists. Survival probability at 15 years were 0.78 (95% CI 0.76 to 0.80) for ER-positive and 0.72 (95% CI 0.68 to 0.77) for ER-negative tumors based on Citizen Scientists classification. Based on pathologist classification, survival probability was 0.79 (95% CI 0.77 to 0.81) for ER-positive and 0.71 (95% CI 0.67 to 0.74) for ER-negative tumors. The hazard ratio for death was 0.26 (95% CI 0.18 to 0.37) at diagnosis and became greater than one after 6.5 years of follow-up for ER scored by Citizen Scientists, and 0.24 (95% CI 0.18 to 0.33) at diagnosis increasing thereafter to one after 6.7 (95% CI 4.1 to 10.9) years of follow-up for ER scored by pathologists.

INTERPRETATION

Crowdsourcing of the general public to classify cancer pathology data for research is viable, engages the public and provides accurate ER data. Crowdsourced classification of research data may offer a valid solution to problems of throughput requiring human input.

Updated UK Recommendations for HER2 assessment in breast cancer

Human epidermal growth factor receptor 2 (HER2) overexpression is present in approximately 15% of early invasive breast cancers, and is an important predictive and prognostic marker. The substantial benefits achieved with anti-HER2 targeted therapies in patients with HER2-positive breast cancer have emphasised the need for accurate assessment of HER2 status. Current data indicate that HER2 test accuracy improved following previous publication of guidelines and the implementation of an external quality assessment scheme with a decline in false-positive and false-negative rates. This paper provides an update of the guidelines for HER2 testing in the UK. The aim is to further improve the analytical validity and clinical utility of HER2 testing by providing guidelines of test performance parameters, and recommendations on the postanalytical interpretation of test results. HER2 status should be determined in all newly diagnosed and recurrent breast cancers. Testing involves immunohistochemistry with >10% complete strong membrane staining defining a positive status. In situ hybridisation, either fluorescent or bright field chromogenic, is used either upfront or in immunohistochemistry borderline cases to detect the presence of HER2 gene amplification. Situations where repeat HER2 testing is advised are outlined and the impact of genetic heterogeneity is discussed. Strict quality control and external quality assurance of validated assays are essential. Testing laboratories should perform ongoing competency assessment and proficiency tests and ensure the reliability and accuracy of the assay. Pathologists, oncologists and surgeons involved in test interpretation and clinical use should adhere to published guidelines and maintain accurate performance and consistent interpretation of test results.

Adverse surgical outcomes in screen-detected ductal carcinoma in situ of the breast

BACKGROUND

The Sloane Project is the largest prospective audit of ductal carcinoma in situ (DCIS) worldwide, with over 12,000 patients registered between 2003 and 2012, accounting for 50% of screen-detected DCIS diagnosed in the United Kingdom (UK) over the period of accrual.

METHODS

Complete multidisciplinary data from 8313 patients with screen-detected DCIS were analysed for surgical outcome in relation to key radiological and pathological parameters for the cohort and also by hospital of treatment. Adverse surgical outcomes were defined as either failed breast conservation surgery (BCS) or mastectomy for small lesions (<20mm) (MFSL). Inter-hospital variation was analysed by grouping hospitals into high, medium and low frequency subgroups for these two adverse outcomes.

RESULTS

Patients with failed BCS or MFSL together accounted for 49% of all mastectomies. Of 6633 patients embarking on BCS, 799 (12.0%) required mastectomy. MFSL accounted for 510 (21%) of 2479 mastectomy patients. Failed BCS was associated with significant radiological under-estimation of disease extent and MFSL significant radiological over-estimation of disease extent. There was considerable and significant inter-hospital variation in failed BCS (range 3-32%) and MFSL (0-60%) of a hospital's BCS/mastectomy workload respectively. Conversely, there were no differences between the key radiological and pathological parameters in high, medium and low frequency adverse-outcome hospitals.

CONCLUSIONS

This evidence suggests significant practice variation, not patient factors, is responsible for these adverse surgical outcomes in screen-detected DCIS. The Sloane Project provides an evidence base for future practice benchmarking.

Assessment of microtubule-associated protein (MAP)-Tau expression as a predictive and prognostic marker in TACT; a trial assessing substitution of sequential docetaxel for FEC as adjuvant chemotherapy for early breast cancer

The TACT trial is the largest study assessing the benefit of taxanes as part of adjuvant therapy for early breast cancer. The goal of this translational study was to clarify the predictive and prognostic value of Tau within the TACT trial. Tissue microarrays (TMA) were available from 3,610 patients. ER, PR, HER2 from the TACT trial and Tau protein expression was determined by immunohistochemistry on duplicate TMAs. Two parallel scoring systems were generated for Tau expression ('dichotomised' vs. 'combined' score). The positivity rate of Tau expression was 50 % in the trial population (n = 2,483). Tau expression correlated positively with ER (p < 0.001) and PR status (p < 0.001); but negatively with histological grade (p < 0.001) and HER2 status (p < 0.001). Analyses with either scoring systems for Tau expression demonstrated no significant interaction between Tau expression and efficacy of docetaxel. Contrary to the hypothesis that taxane benefit would be enriched in Tau negative/low patients, the only groups with a suggestion of a reduced event rate in the taxane group were the HER2-positive, Tau positive subgroups. Tau expression was seen to be a prognostic factor on univariate analysis associated with an improved DFS, independent of the treatment group (p < 0.001). It had no prognostic value in ER-negative tumours and the weak prognostic effect of Tau in ER-positive tumours (p = 0.02) diminished, when considering ER as an ordinal variable. On multivariable analyses, Tau had no prognostic value in either group. In addition, no significant interaction between Tau expression and benefit from docetaxel in patients within the PR-positive and negative subsets was seen. This is now the second large adjuvant study, and the first with quantitative analysis of ER and Tau expression, failing to show an association between Tau and taxane benefit with limited utility as a prognostic marker for Tau in ER-positive early breast cancer patients.

Genetic predisposition to in situ and invasive lobular carcinoma of the breast

Invasive lobular breast cancer (ILC) accounts for 10-15% of all invasive breast carcinomas. It is generally ER positive (ER+) and often associated with lobular carcinoma in situ (LCIS). Genome-wide association studies have identified more than 70 common polymorphisms that predispose to breast cancer, but these studies included predominantly ductal (IDC) carcinomas. To identify novel common polymorphisms that predispose to ILC and LCIS, we pooled data from 6,023 cases (5,622 ILC, 401 pure LCIS) and 34,271 controls from 36 studies genotyped using the iCOGS chip. Six novel SNPs most strongly associated with ILC/LCIS in the pooled analysis were genotyped in a further 516 lobular cases (482 ILC, 36 LCIS) and 1,467 controls. These analyses identified a lobular-specific SNP at 7q34 (rs11977670, OR (95%CI) for ILC = 1.13 (1.09-1.18), P = 6.0 × 10(-10); P-het for ILC vs IDC ER+ tumors = 1.8 × 10(-4)). Of the 75 known breast cancer polymorphisms that were genotyped, 56 were associated with ILC and 15 with LCIS at P<0.05. Two SNPs showed significantly stronger associations for ILC than LCIS (rs2981579/10q26/FGFR2, P-het = 0.04 and rs889312/5q11/MAP3K1, P-het = 0.03); and two showed stronger associations for LCIS than ILC (rs6678914/1q32/LGR6, P-het = 0.001 and rs1752911/6q14, P-het = 0.04). In addition, seven of the 75 known loci showed significant differences between ER+ tumors with IDC and ILC histology, three of these showing stronger associations for ILC (rs11249433/1p11, rs2981579/10q26/FGFR2 and rs10995190/10q21/ZNF365) and four associated only with IDC (5p12/rs10941679; rs2588809/14q24/RAD51L1, rs6472903/8q21 and rs1550623/2q31/CDCA7). In conclusion, we have identified one novel lobular breast cancer specific predisposition polymorphism at 7q34, and shown for the first time that common breast cancer polymorphisms predispose to LCIS. We have shown that many of the ER+ breast cancer predisposition loci also predispose to ILC, although there is some heterogeneity between ER+ lobular and ER+ IDC tumors. These data provide evidence for overlapping, but distinct etiological pathways within ER+ breast cancer between morphological subtypes.

Germline CDH1 mutations in bilateral lobular carcinoma in situ

BACKGROUND

Invasive lobular breast cancer (ILC) and lobular carcinoma in situ (LCIS) are characterised by loss of E-cadherin expression. However germline CDH1 mutations are rare in cases of ILC with no family history of hereditary diffuse gastric cancer (HDGC) and have not been described in women with LCIS.

METHODS

We screened the CDH1 gene in 50 cases of bilateral LCIS/ILC using Sanger sequencing and MLPA.

RESULTS

Sanger sequencing revealed four pathogenic germline mutations, including a novel splicing mutation (c.48+1G>A). The remaining three (c.1465insC, c.1942G>T, c.2398delC) have been previously described. All four cases had bilateral LCIS +/- ILC and no family history of gastric cancer.

CONCLUSION

CDH1 germline mutations have not been previously described in women with LCIS. We have shown that germline CDH1 mutations are associated with early onset of bilateral LCIS with or without ILC in women without a family history of gastric cancer. CDH1 mutation screening should be considered in women with early onset of bilateral LCIS/ILC with no family history of HDGC.

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.

Identification of stage-specific breast markers using quantitative proteomics

Matched healthy and diseased tissues from breast cancer patients were analyzed by quantitative proteomics. By comparing proteomic profiles of fibroadenoma (benign tumors, three patients), DCIS (noninvasive cancer, three patients), and invasive ductal carcinoma (four patients), we identified protein alterations that correlated with breast cancer progression. Three 8-plex iTRAQ experiments generated an average of 826 protein identifications, of which 402 were common. After excluding those originating from blood, 59 proteins were significantly changed in tumor compared with normal tissues, with the majority associated with invasive carcinomas. Bioinformatics analysis identified relationships between proteins in this subset including roles in redox regulation, lipid transport, protein folding, and proteasomal degradation, with a substantial number increased in expression due to Myc oncogene activation. Three target proteins, cofilin-1 and p23 (increased in invasive carcinoma) and membrane copper amine oxidase 3 (decreased in invasive carcinoma), were subjected to further validation. All three were observed in phenotype-specific breast cancer cell lines, normal (nontransformed) breast cell lines, and primary breast epithelial cells by Western blotting, but only cofilin-1 and p23 were detected by multiple reaction monitoring mass spectrometry analysis. All three proteins were detected by both analytical approaches in matched tissue biopsies emulating the response observed with proteomics analysis. Tissue microarray analysis (361 patients) indicated cofilin-1 staining positively correlating with tumor grade and p23 staining with ER positive status; both therefore merit further investigation as potential biomarkers.

Abstract 2505: Expression profiling of cofilin-1 in breast cancer cell lines and biopsies

Introduction. Despite oestrogen and human epidermal growth factor receptor (HER2) targeted therapies improving patient survival, breast cancer continues to be a significant cause of premature death since many tumors do not respond to treatment or acquire resistance. Hence there remains the need to identify novel targets for therapy and biomarkers for prediction of response to treatment. A quantitative proteomics study of matched normal and tumor biopsies identified 63 proteins to be significantly increased or decreased in stage-specific tumors. Some have previously been associated with breast cancer, while others such as cofilin-1 represent new targets for investigation. Cofilin-1 was subject to a range of analyses to determine its association with breast cancer.

Materials and Methods. Western blotting (WB) was performed on protein extracts from breast cancer cell lines and matched normal and tumor biopsies from Cypriot patients with different stages of the disease. Immunohistochemistry (IHC) was carried out on core biopsies from the Leeds Breast Tissue Bank. Multiple reaction monitoring (MRM) mass spectrometry was performed on trypsin-digested protein extracts from biopsies. Data from protein (Human Protein Atlas) and genomics (BioGPS, TiGER, UniGene) databases were assimilated with the experimental results.

Results. WB indicated that cofilin-1 was ubiquitously expressed in tumor cell lines, representative of Luminal A, Luminal B, basal-like, claudin-low and HER2 phenotypes, at higher levels than normal breast cell lines. WB also indicated increased expression of cofilin-1 in invasive carcinoma tissues, compared to matched normal. Patients with ductal carcinoma in situ or fibroadenoma exhibited less clear results, either increasing slightly or remaining unchanged. MRM analysis of three cofilin-1 peptides in tissue extracts of invasive carcinoma patients indicated expression only in tumor. IHC of core biopsies exhibited strong staining for cofilin-1 in ductal invasive carcinoma tissues with no staining in normal breast cells. Genomics and proteomics databases indicate that cofilin-1 is expressed in a diverse range of normal tissues including major organs, gastro-intestinal tract, skin and tonsils. However, mRNA and protein levels are observed to be increased in skin, lung, liver, pancreatic and breast tumors.

Discussion. The original quantitative proteomics data indicated only relatively small changes in expression (less than 2-fold) due to dynamic range limitations of the technique. Additional analytical approaches substantiated that cofilin-1 is significantly up-regulated in advanced breast cancer patients. Further patient sets are required to confirm the importance of cofilin-1 levels in early stages of breast cancer compared to benign tissues. Bioinformatics provided further confidence in our findings, highlighting the value of utilising databases for evidence of disease-specific proteins.

Citation Format: Chris Sutton, Sadr ul-Shaheed, Paul Loadman, Valerie Speirs, Andrew Hanby, Andreas Hadjisavvas, Kyriacos Kyriacou. Expression profiling of cofilin-1 in breast cancer cell lines and biopsies. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2505. doi:10.1158/1538-7445.AM2013-2505

Abstract P2-10-29: Time dependent breast cancer metastasis prediction using novel biological imaging, clinico-pathological and genomic data combined with Bayesian modeling to reduce over-fitting and improve on inter-cohort reproducibility

Background: Breast cancer heterogeneity demands that prognostic models must be biologically driven and recent clinical evidence indicates that future prognostic signatures need evaluation in the context of early versus late metastatic risk prediction. The aim of our work was to identify biologically validated quantitative imaging parameters with improved correlation to clinical outcome, and to address some of the remaining obstacles for a truly robust prognostic model in clinical use.

Method: We identified 4 seed proteins (ezrin/radixin/moesin-cofilin), along with several kinases as biologically relevant subnetwork of proteins that control tumor cell motility and metastasis. Patient-derived breast cancer tumour samples were used to perform a combination of imaging methods such as Fluoresecence lifetime imaging microscopy, automated segmentation and co-localisation intensity analysis. A complexity optimized Bayesian proportional hazard regression model was performed on a total of 419 breast cancer patients to validate time dependent predictions using traditional clinicopathological, genomic and our novel optical imaging-derived parameters. An independent dataset of 300 patient samples from the Leeds Institute of Molecular Medicine is currently being evaluated, representing a large cross centre validation of our integrated model.

Results: We demonstrate that the traditional gold standard clinico-pathological variables are poor predictors for patients that survive long periods, and that their predictive significance (in terms of hazard ratios) varies significantly between two temporal cohorts where the adjuvant treatments are vastly different. Moreover, we investigate the predictive accuracy of a combined imaging/clinicopathological model compared with genomic/clinicopathological models. We demonstrate how to reduce over-fitting to help improve the performance of prognostic models. Results of an integrated model combining genomic and imaging parameters are still awaited.

Discussion: We have produced the first optical imaging-derived multivariate tumour metastatic signature, which measures underlying key biological variables involved in regulating cancer cell motility. Using Bayesian proportional hazards regression in a time-dependent manner, we highlight the inadequacies of existing prediction tools and present a model combining the clinicopathological parameters with our imaging-based metastatic signature, as an integrative reproducible prognostic tool across different temporal cohorts.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-10-29.

Emerging findings in the Cancer Research UK stratified medicine program

TPS10633^

Background: Molecular analysis of tumours may be used to identify those predicted to benefit from novel targeted therapies. The Cancer Research UK programme is piloting plans to apply such testing broadly across the UK healthcare system, linking molecular phenotype to clinical outcomes. Methods: The Stratified Medicine Programme (SMP) aims to develop a model for high quality, large-scale molecular characterization of cancer specimens through an initiative developed in partnership with AstraZeneca, Pfizer, the UK Department of Health and academic researchers. Phase One of the SMP is a two year feasibility study. It aims to demonstrate the submission of consented blood samples and sections of surplus diagnostic formalin-fixed paraffin-embedded tumour tissue from 9,000 patients at centres across the UK to one of three ‘technology hubs’ for mutation testing of genes of potential clinical interest (KRAS, BRAF, NRAS, PIK3CA, TP53, PTEN, TMPRSS2-ERG, EGFR, EML4-ALK and KIT) in six selected tumour types. The tests are technically validated and will be completed in clinically relevant timescales. Data including pathological and treatment information and clinical outcome is also collected for the recruited patients, linked to the genetic data and stored in a central data repository hosted within the National Cancer Registration Service. The study opened in September 2011 at 7 sites across the UK and by the end of 2011, 760 patientswith breast, lung, prostate, colorectal, ovarian cancer or metastatic malignant melanoma had consented to participate. 142 sets of molecular results had been returned to clinical teams. Updated figures will be presented at the meeting, by which time the programme is projected to have accrued 4000 subjects. By 2013, we hope to have developed a scalable model for routine, high quality, prospective molecular characterisation of tumours for NHS cancer patients, with consent for the collection, storage and research use of population-scale genetic and clinical outcome data. We will report the emerging results from the Stratified Medicines Programme and early insights into implications for wider implementation across the UK healthcare system.

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.

Multicentre randomised controlled trial examining the cost-effectiveness of contrast-enhanced high field magnetic resonance imaging in women with primary breast cancer scheduled for wide local excision (COMICE)

OBJECTIVES

To determine whether the addition of magnetic resonance imaging (MRI) to current patient evaluation by triple assessment would aid tumour localisation within the breast and thus reduce the reoperation rate in women with primary breast tumours who are scheduled for wide local excision (WLE), and to assess whether the addition of MRI would be cost-effective for the UK NHS.

DESIGN

A multicentre, randomised controlled, open, parallel group trial with equal randomisation. The main design was supplemented with a qualitative study to assess patients' experiences of the treatment process and care pathway, and involved the development of a non-scheduled standardised interview (NSSI).

SETTING

The study took place at 45 hospitals throughout the UK.

PARTICIPANTS

Women aged 18 years or over with biopsy-proven primary breast cancer who had undergone triple assessment, were scheduled for WLE, and were capable of providing written informed consent.

INTERVENTIONS

Patients were randomised to receive MRI or no MR1. Randomisation was performed using minimisation, incorporating a random element. All MRI was performed at 1.5 T or 1.0 T with a dedicated bilateral breast coil.

MAIN OUTCOME MEASURES

The primary end point of the trial was the reoperation rate. Secondary outcome measures included discrepancies between imaging and histopathology, and the effectiveness of using both procedures; change in clinical management after using MRI; the clinical significance of MRI-only-detected lesions; the rate of interventions; the ipsilateral tumour recurrence rate; patient quality of life (QoL); and cost-effectiveness.

RESULTS

From a total of 1623 patients, 816 were randomised to MRI and 807 to no MRI. No differences in reoperation rates were found between the two groups of patients [MRI patients 18.75%, no MRI 19.33%, difference 0.58%, 95% confidence interval (CI) -3.24 to 4.40]. Therefore, the addition of MRI to conventional triple assessment was not found to be statistically significantly associated with a reduced reoperation rate (odds ratio = 0.96, 95% CI 0.75-1.24, p = 0.7691). The best agreement between all imaging modalities and histopathology with regard to tumour size and extent of disease was found in patients over 50 years old with ductal tumours NST and who were node negative. In the imaging arm, mastectomy was found to be pathologically avoidable for 16 (27.6%) out of 58 patients who underwent the procedure. There were no significant differences between the groups regarding the proportion of patients receiving chemotherapy, radiotherapy or additional adjuvant therapies, as well as for local recurrence-free interval rates and QoL. An acceptable NSSI was developed for use in this population of patients. Economic analysis found no difference in outcomes between the two trial arms.

CONCLUSIONS

The addition of MRI to triple assessment did not result in a reduction in operation rates, and the use of MRI would thus consume extra resource with few or no benefits in terms of cost-effectiveness or HRQoL. However, MRI showed potential to improve tumour localisation, and preoperative biopsy of MRI-only-detected lesions is likely to minimise the incidence of inappropriate mastectomy.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN57474502.

Comparative effectiveness of MRI in breast cancer (COMICE) trial: a randomised controlled trial

BACKGROUND

MRI might improve diagnosis of breast cancer, reducing rates of reoperation. We assessed the clinical efficacy of contrast-enhanced MRI in women with primary breast cancer.

METHODS

We undertook an open, parallel group trial in 45 UK centres, with 1623 women aged 18 years or older with biopsy-proven primary breast cancer who were scheduled for wide local excision after triple assessment. Patients were randomly assigned to receive either MRI (n=816) or no further imaging (807), with use of a minimisation algorithm incorporating a random element. The primary endpoint was the proportion of patients undergoing a repeat operation or further mastectomy within 6 months of random assignment, or a pathologically avoidable mastectomy at initial operation. Analysis was by intention to treat. This study is registered, ISRCTN number 57474502.

FINDINGS

816 patients were randomly assigned to MRI and 807 to no MRI. Addition of MRI to conventional triple assessment was not significantly associated with reduced a reoperation rate, with 153 (19%) needing reoperation in the MRI group versus 156 (19%) in the no MRI group, (odds ratio 0.96, 95% CI 0.75-1.24; p=0.77).

INTERPRETATION

Our findings are of benefit to the NHS because they show that MRI might be unnecessary in this population of patients to reduce repeat operation rates, and could assist in improved use of NHS services.

FUNDING

National Institute for Health Research's Health Technology Assessment Programme.

Lesion size is a major determinant of the mammographic features of ductal carcinoma in situ: findings from the Sloane project

AIM

To assess the radiological features of calcific ductal carcinoma in situ (DCIS) in a large, multicentre dataset according to grade and size, and to investigate the possibility that DCIS has different mammographic features when small.

MATERIALS AND METHODS

The dataset consisted of all Sloane Project DCIS cases where calcification was present mammographically and histological grade and size were available. The radiology data form classifies calcific DCIS as casting/linear, granular/irregular, or punctate. The pathology dataset includes cytonuclear grade and microscopic tumour size. Correlations were sought between the radiological findings and DCIS grade and size. The significance of differences was assessed using the chi-square test and chi-square test for trend.

RESULTS

One thousand, seven hundred and eighty-three cases were included in the study. Of these, 1128, 485, and 170 had high, intermediate, and low-grade DCIS, respectively. Casting calcification was more frequently seen the higher the grade of DCIS, occurring in 58% of high grade, 38% of intermediate grade, and 26% of low-grade cases, respectively (p<0.001). Casting calcification was also increasingly common with increasing lesion size, irrespective of the histological grade (p<0.001). Thus casting calcifications in small (<10mm) high-grade DCIS lesions were seen with a similar frequency (50%) to those in moderate-sized (21-30 mm) intermediate-grade lesions (48%), and to those in large (>30 mm) low-grade lesions (46%).

CONCLUSION

Lesion size has a strong influence on the radiological features of calcific DCIS; small, high-grade lesions often show no casting calcifications, whereas casting calcifications are seen in nearly half of large, low-grade lesions. As small clusters of punctate or granular calcifications may represent high-grade DCIS, an aggressive clinical approach to the diagnosis of such lesions is recommended as the adequate treatment of high-grade DCIS will prevent the occurrence of potentially life-threatening high-grade invasive disease.

External Quality Assurance Schemes: The Impact of Participation in the UK Versus Rest of the World: 5 Year Data from the UK National External Quality Assurance Scheme

The American Society of Clinical Oncology/College of American Pathologists guidelines highlighted the critical importance of quality assurance in diagnostic testing for HER2.Unstained formalin-fixed, paraffin-embedded human breast carcinoma cell line sections were circulated to scheme participants on 15 occasions over 5 years. “Reference laboratories” reported results for the HER2/chromosome 17 ratio and HER2 copy number for 5 years for each cell line. Results from the 5th years participants (3 runs 13, 14, 15) were assessed for the pass rate in UK versus rest of the world (EU, US, Asia, etc). The number of participants was 76-78 laboratories/run (UK 30-35, ROW 43-46).Results: The percentage of laboratories achieving “appropriate” results ranged from 78-82% overall. Significantly higher performance was observed over 3 runs for UK laboratories (91-97%, “appropriate” results) versus ROW laboratories (67-74% “appropriate” results), p = 0.004. All methods used by scheme participants in UK Laboratories had excellent performance rates (Pathvysion, PharmDx, Ventana SISH/Inform, Kreatech Posieden). However in the ROW there was evidence of poor performance, which may be related to the assay format, although numbers of comparisons are relatively small.Participation in external quality assurance schemes is a valuable mechanism for evaluation and benchmarking of performance between laboratories. It also serves to improve consistency of HER2 testing by in situ hybridization. Using data from the UK NEQAS scheme we identified that laboratories whose performance is monitored and linked to an intergrated corrective action component(UK laboratories) perform consistently better than laboratories where performance data alone is provided (ROW). In the UK both participation and adequate performance in a national EQA scheme is required for laboratory accreditation. Whilst, in the context of robust EQA there is no evidence that different methods affect performance, in the ROW implementation of some assays appears sub-optimal. This poor performance does not, however, identify fundamental flaws with these methods, which are currently very well controlled amongst UK users but suggests greater attention to EQA results and change to improve laboratory performance is required in the rest of the world.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6010.

A Functional Role for CERT in Cancer Drug Induced Autophagy and Prognosis in Her2 Positive Breast Cancer

CERT was recently identified in a functional genomic siRNA screen for regulators of multi-drug sensitivity. CERT encodes a ceramide transporter which shuttles the pro-apoptotic lipid ceramide from the endoplasmic reticulum to the golgi. Silencing CERT, promoted sensitivity to paclitaxel, doxorubicin, cisplatin and 5-FU in breast, colon and non-small cell lung cancer cell lines. Further analysis of CERT expression in 18 NCI-60 cancer cell lines together with drug sensitivity data for over 5000 drugs within the NCI database, revealed that elevated CERT expression is associated with multi-drug resistance to diverse cancer cytotoxics. CERT mRNA was significantly elevated in HER2 positive breast cancer cell lines. Consistent with these data, in a primary breast cancer tissue microarray cohort of 356 primary breast cancers with outcome data, CERT protein expression was significantly greater in Her2 positive disease (p&lt;0.0001). Survival analysis indicates that increased CERT expression correlates with significantly poorer long-term survival across the whole cohort and in Her2 positive patients.In order to explore the downstream molecular targets of CERT activity, we used the Affymetrix GeneChip Exon Array to detect gene expression changes following siRNA mediated CERT silencing. Genes that were differentially expressed following CERT silencing were identified and validated by real-time PCR. Significant representation of genes involved in the autophagy pathway were identified. One of these genes, LAMP2, a protein involved in autophagosome-lysosome fusion, is up-regulated following CERT silencing. LAMP2 silencing promotes paclitaxel resistance when depleted from cancer cells. Consistent with a role for CERT silencing in mediating an autophagy response following drug exposure, CERT depletion together with Paclitaxel treatment induces alterations in the autophagy response marker-LC3 similar to those seen in starvation-induced autophagy and an increase in lysosomal activity as visualised by microscopy. These data indicate a role for autophagy in regulating cytotoxic drug response in cancer.The pharmacological targeting of CERT, a poor prognostic marker in breast cancer, may be a rational approach to enhance drug response and patient outcome.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1137.

Methylation Status of Promoters 0K, 0N and a Newly Identified Promoter Regulate ERβ1 Expression in Breast Cancer

Gene expression is regulated at multiple levels, including transcriptional silencing by methylation. ERβ1 is downregulated in breast cancer compared to normal breast and mechanisms surrounding this are unclear. Two novel ERβ mRNA isoforms with distinct 5'-UTRs have been identified, ERβ-0K-1 and ERβ-0N-1. The aim of study was to examine whether methylation at these promoter regions plus a novel promoter identified by our group were involved in ERβ1 regulation (figure 1).Bisulfite modification and direct sequencing analysis were performed for promoters 0K, 0N, and a novel mini CpG island upstream of ERβ exon1 in two ERβ1- and one ERβ1+ breast cancer cell lines. Distinct methylation patterns were observed. Promoter 0N was completely methylated in BT20, partially methylated in MDAMB453 and unmethylated in T47D, while the mini CpG island was methylated in all 3 cell lines. In contrast, promoter 0K was unmethylated. Furthermore, a negative correlation between ERβ1 mRNA expression and the methylation status of promoter 0N was observed in breast cells. To further investigate whether methylation of the ERβ1 promoter was responsible for the loss of ERβ1 expression, BT20 and MDAMB453 cells were treated with either 5-aza-dC, TSA or both, concentrations of which had been previously optimised for each cell line. In BT20 cells which had complete methylation of 0N, both agents were required for induction of ERβ1 and ERβ-0N-1 but not ERβ-0K-1 expression, both of which are part of the 5'UTR region. However in MDAMB453 treatment with 5-aza-dC was sufficient to induce ERβ1 and ERβ-0N-1 expression with no additional re-expression seen with TSA and no effects on ERβ-0K-1. This suggests that promoter 0N is responsible for driving the transcription of ERβ1. On going work is confirming these observations in clinical samples. Our results suggest that promoter 0N plays an important role in regulation of ERβ1 mRNA expression in breast cancer. Our results add to growing literatures which demonstrate ERβ1 is regulated at multiple levels in breast cancer and that DNA methylation is an important mechanism for silencing ERβ1 gene expression.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1148.

miR-92 Is a Novel Regulator of ERβ1 Expression in Breast Cancer

Down-regulation of ERβ1 expression is thought to contribute to carcinogenesis in the breast and consequently is seen in many breast cancers. The molecular mechanisms responsible for the down-regulation of ERβ1 remain unclear. microRNAs are a novel family of regulators of gene expression that have been shown to act on the expression of many critical cancer genes but their relationship with ERβ1 has not so far been demonstrated. The aims of this study were to establish whether miR-92 regulates ERβ1 expression, and whether this regulation plays a role in defining ERβ1 expression levels in breast cancers.Using a bioinformatics approach we initially identified potential binding sites for miR-92 within the 3' untranslated regions of ERβ transcripts using RNAhybrid software (http://bibiserv.techfak.uni-bielefeld.de/rnahybrid/). Two conserved target-sites for miR-92 were identified within the ERβ1 3'-UTR sequence contained within Genebank. We confirmed the expression of these UTRs in MCF7 cells. Next, we performed 3' RACE reactions to determine the 3'-UTR sequence of ERβ1 in MCF7 cellsWe used qPCR analyses of expression in paired normal breast and breast tumour samples (n=6) to examine the relative expression of miR-92 and ERβ1. Upregulation of miR-92 expression was observed in breast tumours compared with normal breast. An inverse relationship with ERβ1 expression was observed in these samples. In a separate cohort of breast tumours (n=36), a significant negative correlation between ERβ1 mRNA and miR-92 was observed (Spearman's correlation coefficient, r = -0.5, p=0.001). Elevated ratios of ERβ1 mRNA /miR92 were also observed in ERβ1 positive compared to ERβ1 negative cells lines.Inhibition of miR-92 in MCF-7 cells increased ERβ1 expression in a dose–dependent manner at RNA levels. Enhanced GFP reporter constructs containing miR-92 binding sites from the 3'-UTR of ERβ1 were used to determine whether miR-92 downregulates ERβ1 via the direct targeting of this 3'-UTR. Inhibition of miR-92 increased the translational efficiency (protein produced per unit of mRNA) of the GFP reporter, confirming that the miR-92 binding sites are a critical regulatory region. Finally, we showed that miR-92 expression was upregulated by 17β-estradiol and downregulated by tamoxifen in MCF7 cells (ERα+ ERβ+) but not in ERβ negative cells (BT20 and MDAMB453), suggesting ERs can mediate miR-92 regulation. Our results demonstrate that ERβ1 expression in breast cancer is regulated by miRNA-92.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4139.

Comparative Biomarker Analysis in 523 Matched Male and Female Breast Cancers

Incidence rates of male breast cancer (MBC) are rising. MBC etiology is poorly understood with most of our current knowledge regarding its biology, natural history and treatment extrapolated from our knowledge of female breast cancer (FBC). Retrospective studies on MBC have suffered from small numbers of cases available from any one centre thus a significant problem in studying this disease is accruing sufficiently large numbers to allow comparative analysis of possible prognostic markers. Using a co-ordinated multi-centre approach, the aim of this study was to conduct the first large scale study to address the relevance of the expression of recognised biomarkers in FBC in the same disease in males. Five hundred and twenty three cases were obtained retrospectively and assimilated into TMAs, including 260 MBCs and 263 cases of stage-matched FBCs. MBC comprised 21 grade 1, 121 grade 2, 68 grade 3, 50 unknown, mean age 67 (range 39-90) with 167 ductal, 4 lobular, 10 papillary, 10, mucinous, 4 DCIS, 1 mixed and 64 unknown. FBC comprised 29 grade 1, 140 grade 2, 94 grade, mean age 58 (range 27-92) with 220 ductal, 23 lobular, 14 mixed and 6 unknown. Four µm TMA sections were analysed using the following biomarkers: hormone receptors (ERα, ERβ1, ERβ2, ERβ5, total PR, PRA, PRB, AR), apoptosis markers (p53, bcl2), basal (CK5/6, CK14) and luminal epithelial markers (CK18, CK19), E-cadherin and HER2. Biomarkers were scored according to published criteria; for ERβ isoforms both nuclear and cytoplasmic immunoreactivity was determined Statistical analysis was conducted using SPSS. Luminal A (ERα+, and/or PR+, HER2-) was seen in 93% of MBC vs. 84% of FBC, Luminal B (ERα+, and/or PR+, HER2+) or HER2 subgroup (ERα-, PR-, HER2+) was not seen in MBC but found in 6% and 2% of FBC, respectively. Basal-like tumours (ERα-, PR-, HER2-, CK5/6+) were infrequent (MBC 2%, FBC 1%) and in MBC these tumours also expressed ERβ isoforms. No differences were observed in grade, stage or LN status between genders. Univariate analysis showed ERα, ERβ1, ERβ5, PRA, AR, p53 were significantly associated with FBC while cytoplasmic ERβ2, bcl2 and e-cadherin were associated with MBC (all P&lt;0.001). Although membranous HER2 was not seen in MBC, many cases displayed nuclear staining. Biomarker profile with respect to clinical outcome is on-going. This work has shown the luminal A phenotype is common in MBC and that gender-specific biomarkers are expressed. As MBC is becoming more common, this information may be useful in identifying biomarkers which might affect outcome.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2109.

DNA damaging effects of the dyes used in sentinel node biopsy: possible implications for clinical practice

OBJECTIVE

This study investigates whether methylene blue (MB), patent blue V (PBV), and indigo carmine (IDC) commonly used in sentinel node biopsy cause DNA damage to breast epithelial cells in vitro.

METHODS

MCF-7 and HB-2 cells were exposed for 5 minutes to the above dyes at the same concentrations used in clinical practice. Following exposure, the comet assay was performed to detect DNA damage. The enzyme, Fapy-DNA glycosylase (FpG) was incorporated to enable the detection of additional oxidative damage.

RESULTS

Both PBV and MB stimulated DNA strand breaks in both MCF-7 and HB2 cell lines (P < 0.05). Levels were elevated over 3-fold (P < 0.05) in MCF-7 and HB2 cells treated with 2.5% PBV and 1% MB, compared with untreated control cells. In contrast, IDC did not stimulate DNA strand break damage at clinically relevant concentrations in either cell line. Addition of Fapy-DNA glycosylase enzyme also revealed significantly (P < 0.05) increased levels of oxidative DNA lesions (ODL) in MCF-7 cells treated with PBV (17.6% ODL) compared with control cells (5.9% ODL).

CONCLUSIONS

This study shows, for the first time, that certain dyes (MB and PBV) commonly used in SLNB have genotoxic effects on breast cells at clinically relevant concentrations in vitro. In vivo studies are now warranted to assess and minimize DNA damage caused by these dyes during SLNB.