The immune micro-environment of inflammatory breast cancer is characterized by an influx of CD163+ tumor-associated macrophages

2556

Background: Inflammatory breast cancer (IBC) is a rare form of breast cancer characterized by rapid progression. A specific immune response seems to be an important driver for the aggressive biological behavior. We previously demonstrated that the spatial composition of the tumor immune micro-environment (TIME) is associated with survival in IBC. However, it remains an enigma how the TIME can contribute to the IBC phenotype. Since the number of tumor-infiltrating lymphocytes (TILs) between IBC and non-inflammatory breast cancer (nIBC) is similar and PD-L1 expression is higher, the functional state or composition of the immune infiltrate might determine the fulminant course of IBC. In this study, we assess the composition of the TIME in both IBC and a cohort of subtype-matched nIBC patients. Methods: We collected clinicopathological variables, evaluated PD-L1 positivity (SP142, Ventana) and scored TILs in a cohort of 161 IBC and 115 molecular subtype-matched nIBC patients. Affymetrix data (for CIBERSORT analysis) was available for 30 IBC and 20 nIBC patients. Immunostainings for CD8+ cytotoxic T cells, FOXP3+ Tregs, CD79a+ activated B cells and CD163+ TAMs (Hematoxylin-DAB) were done according to validated protocols. All slides were were evaluated in Visiopharm to quantify the number (density) and area (relative marker area, RMA) of DAB+ immune cells in both the invasive margin (IM) and the tumor stroma (TS). Results: Patients with IBC presented with higher stage disease (P< 0.001), but there were no other significant differences in clinicopathological parameters. In both cohorts, TAMs were the most abundant immune subset followed by B cells, CD8+ T cells and Tregs. For every subset the number of immune cells was higher in the IM than in the TS. Independent of molecular subtype or stage, IBC patients had more infiltration with TAMs in the TS. This was shown using both density (Median IBC: 424/mm2 vs nIBC: 290/mm2, OR: 0.82, 95% CI 0.76 – 1.00, P= 0.008) and RMA (Median IBC: 1.02% vs nIBC: 0.73%, OR: 0.87, 95% CI 0.77 – 1.00, P= 0.04). As previously described, PD-L1 positivity was significantly higher in the IBC cohort (P= 0.005), but no other significant differences in TIME composition between IBC and nIBC were found. Gene expression of CD163 correlated with the number of CD163+ TAMs (R= 0.38, P= 0.005) and CIBERSORT analysis confirmed a profile enriched for macrophages in IBC. Interestingly, the number of M1 macrophages was also higher in IBC (P= 0.03) and there was a strong correlation between the number of CD163+ TAMs in the TS and the M1 macrophage CIBERSORT subset (R=0.48, P< 0.001), possibly indicating that not only the number but also the functional state of TAMs is different in IBC. Conclusions: Using an extensive immune-phenotyping protocol we demonstrate, in a large cohort of IBC patients, that IBC is characterized by a specific tumor micro-environment in which TAMs play an important role.

The prognostic significance of disseminated tumor cells in bone marrow in patients with operable breast cancer: An updated analysis

e13013

Background: The main cause of death in breast cancer patients is the consequence of the spread and outgrowth of tumor cells at distant sites. The presence of disseminated tumor cells (DTCs) in the bone marrow at diagnosis is considered a predictor for metastasis. Methods: This is an updated analysis of a study in 102 patients with operable breast cancer on the significance of bone marrow micrometastases. The mean follow-up time is 127 months (range 10 - 142, median 129 months). Bone marrow aspirates were analysed for the presence of DTCs by a real time-polymerase chain reaction (RT-PCR) for cytokeratin 19 (CK) and mammaglobin (MAM).The aim of this study is to confirm the association between DTCs and disease-specific survival (DSS) as well as metastasis-free survival (MFS). Results: CK positivity was borderline significant for DSS (p = 0.054). MAM positivity was significantly prognostic for DSS with a hazard ratio (HR) of 3,110 (1,416-6,832) (p = 0,005). Patients positive for both CK and MAM did have a significant worse outcome with a HR for DSS of 7,329 (2,361 – 22,752) (p = 0,001). No significant influence on MFS was identified for CK (p = 0,658) or MAM positivity (p = 0,095). The combination of CK and MAM positivity did however confer a significantly increased risk for MFS (p = 0,043) at a HR of 4,126 (1,409-12,082). Conclusions: This study confirms the role of DTCs as a negative, prognostic factor in patients with operable breast cancer. The combination of CK and MAM is useful to identify this increased risk.

The spatial localization of CD163+ tumor-associated macrophages predicts prognosis and response to therapy in inflammatory breast cancer

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Background: The mechanisms contributing to the aggressive biology of inflammatory breast cancer (IBC) are under investigation. A specific immune response seems to be an important driver, but the functional role of infiltrating immune cells in IBC remains unclear. Tumor-associated macrophages (TAMs) are associated with worse outcome, while CD8+ cytotoxic T cells demonstrate anti-tumor properties in breast cancer. In this study, we assessed spatial associations between CD163+ TAMs, CD8+ cells and cancer cells in IBC, using deep-learning and ecological statistics. Methods: We collected clinicopathological variables, evaluated PDL1-positivity (SP142, Ventana) and scored TILs according to the TIL working group guidelines on H&E slides for 144 IBC patients. Immunostainings for CD8 and CD163 (Hematoxylin-DAB) were done according to validated protocols. All slides were digitized, underwent virtual multiplexing and were evaluated in Visiopharm to quantify the number of DAB+ immune cells. Each immune cell was located using XY coordinates and spatial interactions were examined using a Morisita Horn Index (MHI). Tumor cell coordinates were collected using a deep-learning algorithm applied to the CD8-stained slide. This algorithm was trained in 18 images with more than 150.000 iterations (Deeplabv3+). Results: Complete pathological response (pCR) after neo-adjuvant chemotherapy was achieved by 30.6% (n= 30/98) of the patients with initially localized disease. Besides PDL1-postivity ( P= .03), infiltration with CD8+ T cells ( P= .02) and TAMs ( P= .01) also predicted pCR. However, a likelihood ratio test showed no difference between a model using CD8+ cells, TAMs or TILs. Interestingly, the colocalization of CD163+ and CD8+ cells (MHI >0.83) was associated with pCR (P= .01) and remained significant in a multivariate model (OR: 3.18; 95% CI: 1.04 – 10.6; P= .05) including TIL score, PDL1-positivity and hormone receptor (HR) status. Furthermore, a shorter disease-free survival (DFS) was associated with HR- status, no pCR and the colocalization of TAMs near tumor cells (HR: 3.3; 95% CI: 1.6 – 7.1; P= .002) in a multivariate model. The density of TAMs was not associated with outcome. Conclusions: The impact of TAMs on clinical outcome appears to depend on the spatial arrangement. The number of TAMs solely was not associated with outcome, but patients with more TAMs in proximity of the tumor cells had a worse DFS. Surprisingly, the clustering of TAMs near CD8+ cells was associated with pCR independent of the number of TAMs or TILs.

Phase II COLET study: Atezolizumab (A) + cobimetinib (C) + paclitaxel (P)/nab-paclitaxel (nP) as first-line (1L) treatment (tx) for patients (pts) with locally advanced or metastatic triple-negative breast cancer (mTNBC)

1013

Background: COLET showed that the addition of C (MEK1/2 inhibitor) to P resulted in an increased ORR (38%; Brufsky, SABCS 2017); IMpassion130 demonstrated clinical benefit with the combination of PD-L1 inhibitor A and nP as 1L tx for pts with mTNBC (Schmid, N Engl J Med, 2018). We investigated the efficacy and safety of A + C + P/nP in pts with mTNBC, as this combination may target multiple cancer immune escape mechanisms simultaneously. Methods: In the multi-stage, multi-cohort Phase II COLET study, pts with histologically confirmed mTNBC were randomized 1:1 to receive 1L tx with A 840 mg IV (d1, d15) + C 60 mg qd (d3-d23) + P 80 mg/m2 IV (d1, d8, d15; cohort 2) or + nP 100 mg/m2 (d1, d8, d15; cohort 3) in 28-day cycles until progression or toxicity. The primary endpoint (EP) was confirmed ORR per investigator-assessed RECIST 1.1. Additional EPs were DOR, PFS, OS, safety and exploratory efficacy by PD-L1 status. Results: As of 10 Aug 2018 (6.5-mo median follow-up), 63 and 62 pts were evaluable for efficacy and safety, respectively. In cohorts 2 and 3, 21 pts (66%) and 20 pts (65%) had received neo/adjuvant taxane tx, 9 pts (28%) and 6 pts (19%) had a disease-free interval of ≤12 mo, respectively. All pts had ≥1 AE; 69% and 70% had Gr 3-5 AEs and 47% and 43% had serious AEs in cohorts 2 and 3, respectively. Efficacy data for all pts and by PD-L1 expression on tumor-infiltrating immune cells (IC ≥1%; PD-L1+) are summarized in the Table. Conclusions: ORRs were similar between the A + C + P arm and A + C + nP arm. Numerically higher ORR and PFS were observed in pts with PD-L1+ disease. The combination’s safety profile was consistent with the known individual safety profiles, and A did not increase toxicity. Clinical trial information: NCT02322814. [Table: see text]

Abstract PD9-08: Breast cancer liver metastases vascularize by vessel co-option, not angiogenesis, and have a desert immune phenotype: A histopathological and gene expression study

Phase 3 trials of bevacizumab combined with chemotherapy in metastatic breast cancer have consistently failed to demonstrate a survival benefit for the addition of bevacizumab. When cancers metastasize to highly vascular organs (including the liver), they can utilize vessel co-option, instead of angiogenesis, as a mechanism to obtain a vascular supply (1). We have repeatedly shown by histopathological analyses that almost all (95%, 2 cohorts) breast cancer liver metastases utilize vessel co-option instead of angiogenesis to vascularize (2,3). The prevalence of vessel co-option in breast cancer could explain, at least in part, why anti-angiogenic therapy has been a disappointing therapeutic approach in metastatic breast cancer. Animal models of non-angiogenic liver and lung metastases also displayed resistance to anti-VEGF treatment (3,4).

We have now undertaken a gene expression study (mRNA sequencing) of targeted samples at the tumor-liver interface to discover gene expression patterns and signaling pathways that are associated with non-angiogenic growth of metastatic cancer in the liver (n = 70).

A network to detect biological themes of non-angiogenic growth was built by gene set enrichment analysis. Key components of this network are: cancer cell motility and invasion, epithelial-to-mesenchymal transition, stemness and proliferation. This contrasts with the network of angiogenic liver metastases of which the most important components are inflammation and ECM remodeling. Semi-automated image analyses of CD8-immunostained section of liver metastases confirms that non-angiogenic liver metastases have a significantly lower density of CD8-positive cytotoxic T-lymphocytes at the tumor-liver interface when compared with angiogenic liver metastases (300 cells/mm2 and 1000 cells/mm2, respectively (p&lt;0.0001)). In addition, a clear CXCL13-driven B-cell gene expression signature is associated with angiogenic growth of liver mets but is absent in non-angiogenic growth of breast cancer liver metastases. Gene expression patterns that may be play a role in vessel co-option are the up-regulation of LAMA3, LAMB3, LAMC2, coding for the 3 subunits of laminin-5, and of ITGA3, ITGB1, ITGA6 and ITGB4, coding for both integrin-receptors of laminin-5. This supports the concept of 'adhesive' vessel co-option during which cancer cells use the basement membrane of the co-opted blood vessels as a soil (5). In addition, the claudin-2 gene (CLDN2) is significantly overexpressed in non-angiogenic liver metastases which is consistent with earlier reports on the role of claudin-2 during breast cancer metastasis to the liver (6).

In conclusion, we provide evidence, based on morphology and gene expression, for the almost exclusive non-angiogenic growth of breast cancer liver metastases. In addition, non-angiogenic breast cancer liver metastases are characterized by a desert immune phenotype. Both observations can have an impact on the treatment strategy of patients with metastatic breast cancer.

References: 1. 10.1038/nrc.2018.14 – 2. 10.1038/sj.bjc.6601727 – 3. 10.1038/nm.4197 – 4. 10.1002/path.4845 – 5. 10.1097/NEN.0b013e318233afd7 – 6. 10.1038/onc.2010.518

Citation Format: Vermeulen PB, van Dam P-J, Daelemans S, Latacz E, Joye I, Kockx M, Dirix P, Verhoef K, Grunhagen D, Huget P, Van Laere S, Dirix LY. Breast cancer liver metastases vascularize by vessel co-option, not angiogenesis, and have a desert immune phenotype: A histopathological and gene expression study [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 PD9-08.

Updated efficacy and safety of avelumab in metastatic urothelial carcinoma (mUC): Pooled analysis from 2 cohorts of the phase 1b Javelin solid tumor study

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Background: Avelumab, a fully human anti‒PD-L1 IgG1 antibody, has shown promising efficacy and safety in 2 cohorts of patients (pts) with mUC. We now report updated data from a pooled analysis of these pts with mUC from JAVELIN Solid Tumor (NCT01772004) and further characterize the clinical activity of avelumab in this disease. Methods: Pts with mUC progressed after platinum-based therapy or cisplatin ineligible received avelumab 10 mg/kg 1-hour IV Q2W. Tumors were assessed every 6 weeks by independent review (RECIST v1.1). Endpoints included objective response rate (ORR), duration of response (DOR), progression-free survival (PFS), overall survival (OS), safety (NCI CTCAE v4.0), and tumor PD-L1 expression. Results: As of Jun 9, 2016, 249 pts had received avelumab for a median of 12 weeks (range 2-92) and were followed up for a minimum of 6 weeks. Primary tumor site was upper tract (renal pelvis/ureter) in 23.3% and lower tract (bladder/urethra) in 76.7%. 242 pts (97.2%) had progressed on prior platinum therapy and 7 pts (2.8%) were platinum naive. In 161 post-platinum pts with ≥6 months of follow-up, confirmed ORR was 17.4% (95% CI 11.9-24.1; complete response in 6.2%) with a disease control rate of 39.8%. Response was ongoing in 23/28 responders at data cut (82.1%; median DOR not reached), and the 24-week durable response rate was 92.3% (95% CI 72.6-98.0). Responses occurred across PD-L1 expression levels tested (≥5% and < 5% tumor cell‒staining [25.4% and 13.2%]). In all post-platinum pts (n = 242), median PFS was 6.6 weeks (95% CI 6.1-11.6), median OS was 7.4 months (95% CI 5.7-10.3) and 6-month OS rate was 54.9 (95% CI 47.7-61.7). Treatment-related adverse events (TRAE) of any grade occurred in 166/249 pts (66.7%); most common (≥10%) were infusion-related reaction (22.9%, all grade ≤2) and fatigue (16.1%). 21 pts (8.4%) had a grade ≥3 TRAE (fatigue [1.6%] and asthenia [0.8%] in > 1 pt). 34 pts (13.7%) had an immune-related AE (grade ≥3 in 2.4%). There was 1 treatment-related death (pneumonitis). Conclusions: Avelumab was well tolerated and showed durable responses in heavily pretreated pts with mUC, irrespective of tumor PD-L1 expression status. Clinical trial information: NCT01772004.

Circulating tumour cells and survival in abiraterone- and enzalutamide-treated patients with castration-resistant prostate cancer

5049

Background: A heterogeneous landscape of patients with metastatic castration-resistant prostate cancer (mCRPC) exists in current clinical practice. We investigated the prognostic value of CTC enumeration and dynamics, in the context of second-line endocrine therapies (i.e. abiraterone or enzalutamide). Methods: In a prospective, multicentre study blood samples were collected from patients with mCRPC at baseline (n = 147) and follow-up (n = 95/147(64.6%)). At baseline, patients were stratified in favourable ( < 5 CTCs/7.5mL) and unfavourable (≥5 CTCs/7.5mL) groups, whereas at follow-up, in those demonstrating a stable, in- or decreasing CTC count. PFS and OS were compared between groups. PSA changes at 10-12 weeks were evaluable in 83 patients. Results: Patients with ≥5 CTCs/7.5 mL (n = 59) at baseline had a shorter PFS (3.9 vs. 11.3 months, p< 0.0001) and OS (9.34 months vs. not reached, p< 0.0001). Patients demonstrating increasing CTCs (n = 21) on therapy had a shorter PFS (4.03 vs. 10.36 vs. 13.08 months, p < 0.0001) and OS (11.2 months vs. not reached, p < 0.0001), compared to patients with decreasing (n = 41) and stable (n = 33) CTCs, respectively. Multivariate Cox regression showed that the number of CTCs (HR (95%CI): 1.0054 (1.0006–1.010), p= 0.0260) and an increasing follow-up CTC count (HR (95%CI): 2.8987 (1.2856–6.536), p= 0.0103) were independent predictors of PFS. CTC increase was the sole independent predictor for OS (HR (95%CI): 7.3512 (1.7953–30.101), p= 0.0055). At 10-12 weeks, a PSA response of ≥30% and ≥50% was achieved in 46/83 (55.4%) and 33/83 (39.8%) patients, respectively, which was statistically different between chemo-naive or -pretreated patients (≥30%: p= 0.0395), patients with increasing, stable or decreasing CTC counts (≥30%: p= 0.0019; ≥50%: p= 0.0032), and patients with increasing or stable/decreasing CTC counts (≥30%: p= 0.0006; ≥50%: p= 0.0014). Conclusions: CTC levels are associated with PFS and OS in mCRPC patients, starting a new line of endocrine therapy. Follow-up CTC enumeration is associated with PSA response and its dynamics is an independent predictor of PFS and OS, thereby demonstrating the pharmacodynamic properties of CTCs.

Prevalence and heterogeneity of androgen receptor splice variants and intra-AR structural variation in patient with castration-resistant prostate cancer

11530

Background: Androgen receptor splice variant 7 (AR-V7) is linked to a priori resistance to abiraterone acetate and enzalutamide. However, AR-V7 negativity does not necessarily indicate responsiveness and up to 20% of AR-V7 positive patients do demonstrate moderate response to these second-line endocrine therapies. Methods: Peripheral blood samples from patients with CRPC (n = 30) starting a new line of systemic therapy were subjected to comprehensive profiling of AR. AR splice variant (ARV) profiling for eight isoforms was performed by targeted RNA-Seq on CellSearch-enriched circulating tumour cells. Low-pass whole-genome and targeted sequencing of the entire AR gene in plasma-derived circulating cell-free DNA allowed the assessment of copy number status and structural rearrangements, respectively. ARV expression, structural variation, copy number alterations and ligand-binding domain mutations were combined and correlated to clinicopathologic parameters. Results: Twenty-five out of 30 patients (83%) demonstrated an aberration in AR. Twenty out of 30 patients (66.7%) demonstrated AR amplifications. Interestingly, 15/30 patients had intra-AR structural variants, of whom 14 expressed ARVs. In the context of endocrine treatment, 15/26 (57.7%) patients were ARV-positive with 13/15 patients having less than 6 months benefit from their therapy (Fisher’s exact test, p = 0.0115). ARV expression was heterogeneous with 10/15 ARV-positive patients expressing several ARV. Notably, AR-V7 was most frequently detected, however AR-V3 was 3.5x more abundant (Wilcox signed rank, p = 0.0029). In 17 patients, a baseline AR profile was available and demonstrated how having any ARV was associated with progression-free survival (HR: 4.53, 95%CI: 1.424–14.41; p = 0.0105). In the poor response group, 6/17 (35.2%) were AR-V7 negative, of whom 4 carried other AR aberrations. Conclusions: Comprehensive AR profiling on liquid biopsies is feasible and provides new insights into the mechanisms driving endocrine resistance. Clinical validation, by means of a non-interventional, prospective and multicentric study, is essential and currently ongoing.

Dynamic prediction in breast cancer: proving feasibility in clinical practice using the TEAM trial

BACKGROUND

Predictive models are an integral part of current clinical practice and help determine optimal treatment strategies for individual patients. A drawback is that covariates are assumed to have constant effects on overall survival (OS), when in fact, these effects may change during follow-up (FU). Furthermore, breast cancer (BC) patients may experience events that alter their prognosis from that time onwards. We investigated the 'dynamic' effects of different covariates on OS and developed a nomogram to calculate 5-year dynamic OS (DOS) probability at different prediction timepoints (tP) during FU.

METHODS

Dutch and Belgian postmenopausal, endocrine-sensitive, early BC patients enrolled in the TEAM trial were included. We assessed time-varying effects of specific covariates and obtained 5-year DOS predictions using a proportional baselines landmark supermodel. Covariates included age, histological grade, hormone receptor and HER2 status, T- and N-stage, locoregional recurrence (LRR), distant recurrence, and treatment compliance. A nomogram was designed to calculate 5-year DOS based on individual characteristics.

RESULTS

A total of 2602 patients were included (mean FU 6.2 years). N-stage, LRR, and HER2 status demonstrated time-varying effects on 5-year DOS. Hazard ratio (HR) functions for LRR, high-risk N-stage (N2/3), and HER2 positivity were HR = (8.427 × 0.583[Formula: see text], HR = (3.621 × 0.816[Formula: see text], and HR = (1.235 × 0.851[Formula: see text], respectively. Treatment discontinuation was associated with a higher mortality risk, but without a time-varying effect [HR 1.263 (0.867-1.841)]. All other covariates were time-constant.

DISCUSSION

The current nomogram accounts for elapsed time since starting adjuvant endocrine treatment and optimizes prediction of individual 5-year DOS during FU for postmenopausal, endocrine-sensitive BC patients. The nomogram can facilitate in determining whether further therapy will benefit an individual patient, although validation in an independent dataset is still needed.

Blood microvessel density, lymphatic microvessel density and lymphatic invasion in predicting melanoma metastases: systematic review and meta-analysis

In malignant melanoma (MM) there is an urgent need to identify new markers with predictive value superior to the traditional clinical and histological parameters. Angiogenesis and lymphangiogenesis have been recognized as critical processes in tumour growth and metastasis development, and numerous studies have evaluated the significance of these parameters in predicting the prognosis in solid tumours, including MM. We set out to determine whether angiogenesis, lymphangiogenesis and lymphatic invasion (LI) are valuable prognostic markers in MM. We systematically reviewed the available literature and subsequently performed a meta-analysis on the compiled data. To be eligible for the systematic review, a study had to provide the microvessel density (MVD), the lymphatic vessel density (LVD) or information about LI, assessed by immunohistochemistry on the primary site in patients with MM. To be evaluable for the meta-analysis, a study also had to provide information on clinical outcome. We approached selected studies with the Reporting recommendations for tumour marker (REMARK) criteria, verifying whether they had followed the recommendations. In total, nine angiogenesis, seven lymphangiogenesis and 10 LI studies were included in our meta-analysis, representing 419, 474 and 802 patients, respectively. Using meta-analysis, we showed that peritumoral LVD and the presence of LI have prognostic value for patients with MM. In contrast, MVD and intratumoral LVD did not have prognostic value in these patients. LVD and LI seem to have prognostic value for patients with MM.

Mechanisms of tumour vascularization in cutaneous malignant melanoma: clinical implications

Malignant melanoma represents < 10% of all skin cancers but is responsible for the majority of skin-cancer-related deaths. Metastatic melanoma has historically been considered as one of the most therapeutically challenging malignancies. Fortunately, for the first time after decades of basic research and clinical investigation, new drugs have produced major clinical responses. Angiogenesis has been considered an important target for cancer treatment. Initial efforts have focused primarily on targeting endothelial and tumour-related vascular endothelial growth factor signalling. Here, we review different mechanisms of tumour vascularization described in melanoma and discuss the potential clinical implications.

Abstract P1-04-03: Genome-wide analysis of copy number variations and mutation profiles of single circulating tumour cells using massively parallel paired-end sequencing

INTRODUCTION

Recent advances in single cell isolation techniques and next generation sequencing (NGS) have paved the way for the genome-wide molecular analysis of individual circulating tumour cells (CTCs) in patients with metastatic carcinomas. Here we present the results of a pilot study evaluating the feasibility and reliability of NGS of single CTC from whole blood samples.

MATERIALS & METHODS

Single cells of the human breast cancer cell line HCC38 were harvested from spiked blood samples in a semi-automated workflow consisting of immunomagnetic enrichment using the CellSearch system and dielectrophoretic cell sorting using the DEPArray system. DNA was isolated and amplified using the Ampli1 whole genome amplification (WGA) kit and subjected to low-coverage genome-wide paired-end sequencing for copy number variation (CNV) analysis and targeted re-sequencing of 200 cancer-related genes for somatic mutation analysis.

RESULTS

Single-cell WGA products of four HCC38 cells were subjected to whole genome sequencing for CNV analysis. Average coverage depth was 0,68x. At a binning window of 50 kb, detection results of CNVs in single-cell samples were highly consistent (&gt;81% copy number concordance per bin genome wide) with CNV profiles from non-amplified multi-cell samples of the same cell line. We could demonstrate that part of the discordance was due to the acquisition of novel DNA-rearrangements in the single cells. Three of the single-cell WGA products were additionally subjected to targeted re-sequencing for mutation analysis of 200 selected genes, of which the analysis is currently ongoing.

DISCUSSION

Our study demonstrates the feasibility of a comprehensive genome-wide CNV analysis and targeted mutation analysis using NGS of single tumour cells isolated from whole blood samples in a highly automated isolation workflow. This approach provides a robust framework for the study of intercellular heterogeneity within the CTC population in blood samples of patients with (metastatic) breast cancer. In addition, our results document the extent of WGA-induced bias of a recently commercialized PCR-based WGA kit.

These authors contributed equally to the data presented in this abstract.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-04-03.

Abstract P2-05-04: Comparative expression profiling of patient samples and preclinical models of inflammatory breast cancer reveals gene signatures of epithelial plasticity and suppression of TGFb signaling

Introduction: Genome-wide expression profiling of samples from patients with and without Inflammatory Breast Cancer (IBC) has revealed novel insights into the biology of IBC. The present study was undertaken to compare these novel insights with data obtained from all available preclinical IBC models including 2 new models that we have recently developed that recapitulate the characteristics of IBC including retention of E-cadherin, formation of tumor emboli and encircling lymphoangiogenesis

Materials and Methods: Five replicates of 7 preclinical IBC models (SUM149, SUM190, FC-IBC-01, FC-IBC-02, MDA-IBC-03, KPL-4, and Mary-X) were profiled using Affymetrix HGU133plus2 GeneChips. Using a nearest shrunken centroid algorithm, each expression profile was classified according to an IBC-specific signature identified in patient samples. Available expression profiles were further queried for expression patterns related to Epithelial-to-Mesenchymal Transition (EMT), TGFβ-signaling and IBC-specific patterns of transcription factor activation.

Results: Application of our IBC-specific signature (posterior probabilities exceeded 0.50 in at least 4/5 replicates) revealed that out of 7 pre-clinical models of IBC, 3 of these robustly classified as IBC (FC-IBC-01, FC-IBC-02, and KPL-4). All preclinical IBC models were characterized by retention of E-Cadherin expression, absence of ZEB1 expression, attenuated expression of specific components of the TGFβ pathway (TGFβR2, SMAD3, SMAD7, and TGFβ1), and ambiguous activation patterns of several transcription factors involved in regulating cellular plasticity and cell fate decisions (Up in IBC: NR4A2, RARB/RXRA, PTX3, GSC2, and ZEB1; Down in IBC: SOX10, PAX5, and SMAD2). For each of the molecular alterations described above, Z-scores greater than 2 were achieved in at least 4/5 replicates.

Conclusions: The observations that we have made using IBC patient tumor samples with regards to EMT, cell plasticity and TGFβ-signaling are corroborated in pre-clinical models of IBC using current analytic approaches, despite the fact that expression patterns of the majority of preclinical models of IBC deviate from the IBC-specific expression patterns observed in patient samples. Our data suggest that despite their highly invasive nature, IBC cancer cells retain an epithelial cell phenotype characterized by E-cadherin expression and loss of ZEB1 which appears to be mediated by, amongst others, attenuated TGFβ-signaling. This study strengthens our hypothesis that cancer cells from IBC exhibit cohesive invasion, and invade as a unit, possibly explaining the presence of florid tumour emboli which is a primary characteristic observed in IBC.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-05-04.

Do type 1 receptor tyrosine kinases inform treatment choice? A prospectively planned analysis of the TEAM trial

BACKGROUND

Epidermal growth factor receptors contribute to breast cancer relapse during endocrine therapy. Substitution of aromatase inhibitors (AIs) may improve outcomes in HER-positive cancers.

METHODS

Tissue microarrays were constructed. Quantitative analysis of HER1, HER2, and HER3 was performed. Data were analysed relative to disease-free survival and treatment using outcomes at 2.75 and 6.5 years.

RESULTS

Among 4541 eligible samples, 4225 (93%) had complete HER1-3 data. Overall, 5% were HER1-positive, 13% HER2-positive, and 21% HER3-positive; 32% (n=1351) overexpressed at least one HER receptor. In the HER1-3-negative subgroup, the hazard ratio (HR) for upfront exemestane vs tamoxifen at 2.75 years was 0.67 (95% confidence interval (CI), 0.52-0.87), in the HER1-3-positive subgroup, the HR was 1.15 (95% CI, 0.85-1.56). A prospectively planned treatment-by-marker analysis demonstrated a significant interaction between HER1-3 and treatment at 2.75 years (HR=0.58; 95% CI, 0.39-0.87; P=0.008), as confirmed by multivariate regression analysis adjusting for prognostic factors (HR=0.55; 95% CI, 0.36-0.85; P=0.005). This effect was time dependent.

CONCLUSION

In the 2.75 years prior to switching patients initially treated with tamoxifen to exemestane, a significant treatment-by-marker effect exists between AI/tamoxifen treatment and HER1-3 expression, suggesting HER expression could be used to select appropriate endocrine treatment at diagnosis to prevent or delay early relapses.

mRNA expression profiles in circulating tumor cells (CTCs) of patients with metastatic breast cancer (MBC) treated with aromatase inhibitors (AI)

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Background: Enumeration of CTCs can be used to assess prognosis in MBC and to evaluate treatment response. Besides enumeration, molecular CTC characterization is a promising tool to develop a more personalized treatment approach. Here, we evaluated the association between mRNA expression of currently known CTC-specific genes and response to first-line AI in MBC patients with estrogen receptor (ER)+ primary tumors. Methods: CTCs were isolated and enumerated from blood of 25 MBC patients before first-line therapy with an AI. Fourteen patients received a non-steroidal AI (8 letrozole, 6 anastrozole) and 11 patients were treated with exemestane. mRNA expression levels of 96 genes were measured by quantitative RT-PCR as previously described (Sieuwerts et al. Clin Cancer Res. 17:3600-3618, 2011). Expression levels of these genes were studied for their association with time to progression (TTP) after start first-line AI. Results: Median TTP was 338 (range 14–1,239) days. Median baseline CTC count for the 25 patients was 14 (range 0–753). In this relatively small cohort, the clinically relevant cut-off level of ≥5 CTCs in association with TTP did not reach statistical significance (Hazard Ratio [HR] 4.76, 95% Confidence Interval [CI]: 0.59–38.22, P=0.14). For type of AI, when comparing steroidal with non-steroidal AI, the measures in Cox univariate regression analysis were HR 2.54 (95% CI: 0.67–9.64), P=0.17. A 10-gene CTC profile was constructed based on the Wald statistics of the contribution of the individual genes in univariate Cox regression analysis of TTP. To identify patients with good and poor outcome, the Wald corrected sum of the 10 genes was used to dichotomize the continuous 10-gene predictor (HR 12.87 [95% CI: 1.60–103.56], P=0.016). In multivariate analysis, corrected for the clinically relevant variables type of AI and CTC count, only the 10-gene CTC profile was an independent factor associated with TTP (HR 12.46 [95% CI: 1.29-120.08], P=0.029). Conclusions: A 10-gene CTC predictor was constructed which distinguishes good and poor outcome to first-line AI in MBC patients. This profile is currently being validated in an independent group of patients.

Abstract P3-10-08: A new in vitro method of growing and studying inflammatory breast cancer emboli

Inflammatory breast cancer (IBC) is the deadliest form of breast cancer, presenting as intralymphatic emboli. Emboli within the dermal lymphatic vessels are thought to contribute to rapid metastasis. The lack of appropriate in vitro models has made it difficult to accurately study how IBC emboli metastasize. To date, attempts at creating IBC tumor emboli in vitro have used 3-dimensional culture on a solid layer of MatrigelTM, which does not resemble the physical properties of the lymphatic system. Dermal lymphatic fluid produces oscillatory fluid shear forces and is 1.5–1.7-fold more viscous than water with a pH range of 7.5–7.7. We have established a method for forming tumor emboli by culturing the IBC cell lines in suspension with either polyethylene glycol- or hyaluronic acid-containing medium and oscillatory fluid shear forces. Non-IBC cells do not form emboli under identical conditions. In vitro IBC emboli were analyzed for expression of markers associated with patient emboli and their ability to undergo amoeboid movement. In a direct comparison, the in vitro IBC emboli closely resemble IBC patient emboli with respect to size, composition and E-cadherin expression. Further, cells from the emboli are able to invade in clusters via RhoC GTPase-dependent amoeboid movement. Invasion by clusters of IBC cells is disrupted by exposure to TGFβ. This study provides a biologically relevant in vitro model to accurately grow and study inflammatory breast cancer biology and metastasis.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-10-08.

Abstract P2-01-09: Tumor cell emboli in the lung and transcriptional profiles of circulating tumor cells derived from different vascular compartments in patients with metastatic breast cancer

Background: We have shown that in up to 50% of patients with metastatic breast cancer (MBC) significantly higher numbers of circulating tumor cells (CTCs) can be detected in central venous blood (CVB) as compared to peripheral venous blood (PVB), suggesting that the lungs might retain a substantial number of CTCs from the blood stream (Peeters et al. Br J Cancer 2011). The aim of this study was 1) to investigate the relation between elevated numbers of CTCs and the presence of (intravascular) tumor cell emboli (TCE) in the lung in patients with advanced carcinomas, and 2) to investigate whether CTCs derived from CVB and PVB exhibit differential transcriptional characteristics.

Methods: Seven patients with MBC and 1 patient with metastatic cervical carcinoma, all suffering from end-stage disease, were included in the first part of this study. CTCs were isolated and enumerated with the CellSearch system (Veridex, Raritan, NJ, USA) in 7.5 ml blood obtained from the central venous access catheter (CVB) and/or a peripheral vein (PVB). All blood samples were obtained within 5 days prior to death. The presence of TCE was studied in lung tissue samples obtained at autopsy. For the second study aim, paired CVB and PVB CTC samples were collected from an additional 10 MBC and 2 LABC patients. Transcriptional profiles were obtained for 91 breast cancer related genes as described by Sieuwerts et al. (Clin Cancer Res 2011).

Results: Multiple TCE were observed in 4 out of 6 patients with highly elevated numbers of CTCs (&gt;100 CTC/7.5 ml blood). These TCE were located exclusively intravascularly in 2 patients, while the other 2 patients had a more diffuse infiltration pattern with perivascular and lymphovascular TCE. All 4 patients had a history of rapidly evolving respiratory distress in the last week of life although radiological examination of the lungs did not show significant interval changes. In another 2 MBC patients with &gt;100 CTCs and 2 MBC patients with &lt;5 CTCs, no TCE were observed. Of the 12 patients included for transcriptional CTC analysis, 8 patients had ≥5 CTCs in both blood samples. In line with our previous findings, 5/8 patients had at least a 15% higher CTC count in CVB than in PVB. Unsupervised hierarchical clustering of transcriptional profiles was primarily driven by the absence or presence of CTCs in the blood samples and revealed no significant differences between CTC samples derived from CVB or PVB from the same patient.

Conclusions: TCE were observed in 4 out of 6 patients with highly elevated numbers of CTCs. In these patients, cumulative entrapment of CTCs in the lung might have contributed to respiratory dysfunction. High numbers of CTC might therefore represent an oncological emergency. Transcriptional profiling of 91 breast cancer related genes revealed no substantial difference in gene expression of CTCs derived from CVB and PVB, suggesting that CTC entrapment by the lung is a rather passive process in advanced cancer patients. These findings will be further challenged by comparing the obtained profiles with gene expression profiles of 13 additionally selected homing markers in these samples.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-01-09.

Abstract P2-01-08: Different numbers and prognostic significance of circulating tumour cells in patients with metastatic breast cancer according to immunohistochemical subtypes

Introduction: The enumeration of circulating tumour cells (CTCs) with the EPCAM-based CellSearch system has prognostic significance in patients with metastatic breast cancer (MBC). However, breast cancer has been shown to be a molecularly heterogeneous disease. The aim of this study was to assess potential differences in the detection and prognostic significance of CTCs according to the immunohistochemically defined molecular subtypes of breast cancer.

Methods: CellSearch CTC counts were obtained from 110 patients with MBC prior to first line systemic treatment, treated at GZA Hospitals Sint-Augustinus between november 2007 and december 2011. Clinicopathological variables were prospectively entered in a database. Based on the St-Gallen surrogate definitions of intrinsic breast cancer subtypes (Goldhirsch et al. Ann Oncol 2011), patients were divided in 5 groups: luminal A (ER/PR+, HER2−, Bloom-Richardson histological grade I-II), luminal B – HER2 negative (ER/PR+, Her2−, grade III), luminal B – HER2 positive (ER/PR+, HER2+, any grade), HER2 positive – non luminal (ER/PR−, HER2+), and triple negative (TN) (ER/PR−, HER2−). Differences in progression free survival (PFS) and overall survival (OS) according to the FDA approved prognostic cut-off of ≥5 CTC/7.5 ml blood were estimated using Kaplan Meier and Cox proportional hazard statistics.

Results: CTC were detected in 78 of 110 (71%) patients. Higher detection rates and numbers of CTC were observed in patients with luminal A and TN breast cancer as compared to patients with luminal B and HER2 positive disease. However, no differences in positivity rates were observed between molecular subtypes according to the 5 CTC prognostic cut-off point (table 1). After a median FU time of 3.1 years, 39 patients had died. In the total study population, the presence of ≥5 CTC was an independent predictor of PFS and OS in multivariate analysis (PFS: HRCTC≥5=2.236 (1.366–3.658), p = 0.001; OS: HRCTC≥5=3.180 (1.553–6.509), p = 0.002). When analyzing subgroups separately, a lower prognostic power was observed in the HER2 positive and luminal B subgroups.

Abstract P3-10-04: Regulation of inflammatory breast cancer cell invasion through Akt1/PKBα phosphorylation of RhoC GTPase

With a 42% and 18% 5- and 10-year respective disease-free survival rate, inflammatory breast cancer (IBC) is arguably the deadliest form of breast cancer. IBC invades the dermal lymphatic vessels of the skin overlying the breast and as a consequence nearly all women have lymph node involvement and ∼1/3 have gross distant metastases at the time of diagnosis. One year after diagnosis ∼90% of patients have detectable metastases, making IBC a paradigm for lymphovascular invasion. Understanding the underlying mechanisms of the IBC metastatic phenotype is essential for new therapies. Work from our laboratory and others show distinct molecular differences between IBC and non-inflammatory breast cancers. Previously we demonstrated that RhoC GTPase is a metastatic switch responsible for the invasive phenotype of IBC. In the current study we integrate observations made in IBC patients with in vitro analysis. We demonstrate that the PI3K/Akt signaling pathway is crucial in IBC invasion. Key molecules involved in cytoskeletal control and cell motility are specifically upregulated in IBC patients compared with stage and cell-type-of-origin matched non-inflammatory breast cancer patients. Distinctively, RhoC GTPase is a substrate for Akt1 and its phosphorylation is absolutely essential for IBC cell invasion. Further our data show that Akt3, not Akt1 has a role in IBC cell survival. Together our data demonstrate a unique and targetable pathway for IBC invasion and survival.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-10-04.

Relationship between specific adverse events and efficacy of exemestane therapy in early postmenopausal breast cancer patients

BACKGROUND

Many adverse events (AEs) associated with aromatase inhibitors (AIs) involve symptoms related to the depletion of circulating estrogens, and may be related to efficacy. We assessed the relationship between specific AEs [hot flashes (HF) and musculoskeletal AEs (MSAE)] and survival outcomes in Dutch and Belgian patients treated with exemestane (EXE) in the Tamoxifen Exemestane Adjuvant Multinational (TEAM) trial. Additionally, the relationship between hormone receptor expression and AEs was assessed.

METHODS

Efficacy end points were relapse-free survival (RFS), overall survival (OS) and breast cancer-specific mortality (BCSM), starting at 6 months after starting EXE treatment. AEs reported in the first 6 months of treatment were included. Specific AEs comprised HF and/or MSAE. Landmark analyses and Cox proportional hazards models assessed survival differences up to 5 years.

RESULTS

A total of 1485 EXE patients were included. Patients with HF had a better RFS than patients without HF [multivariate hazard ratio (HR) 0.393, 95% confidence interval (CI) 0.19-0.813; P = 0.012]. The occurrence of MSAE versus no MSAE did not relate to better RFS (multivariate HR 0.677, 95% CI 0.392-1.169; P = 0.162). Trends were maintained for OS and BCSM. Quantitative hormone receptor expression was not associated with specific AEs.

CONCLUSIONS

Some AEs associated with estrogen depletion are related to better outcomes and may be valuable biomarkers in AI treatment.

VEGF-A-independent and angiogenesis-dependent tumour growth in patients with metastatic breast cancer

BACKGROUND The mechanisms of tumour progression during anti-VEGF-A treatment are poorly understood. PATIENTS AND MATERIALS Two patients with metastatic breast cancer are described who developed new metastases while receiving anti-VEGF-A treatment. Angiogenic parameters were determined by CD34/Ki67 double staining, Chalkley counts (CC) and endothelial cell proliferation fractions (ECP). RT-PCR Taqman low-density arrays with a gene panel of 94 angiogenesis-related genes were performed on both metastases and compared to 10 unselected primary breast tumours. RESULTS Both lesions showed a high and intermediate CC of, respectively, 7.5±0.62 and 4.8±0.2. Both lesions had elevated ECP values of 14% and 8%. Low-density array screening showed that VEGFR1 mRNA was overexpressed in both samples (z-score=7.85 and 7.81) compared to control samples (out of range [min-max]). Additional analysis confirmed this finding at the protein level by immunohistochemistry. CONCLUSION These observations suggest that tumour progression under continuous anti-VEGF-A continues to be angiogenesis dependent. Further exploration is needed to identify the mechanisms of anti-VEGF-A resistance in order to design combination-targeted therapies.

Validation of IHC4 algorithms for prediction of risk of recurrence in early breast cancer using both conventional and quantitative IHC approaches

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Background: Hormone receptors, HER2 and Ki67 are residual risk markers in early breast cancer. Combining these markers into a unified algorithm (IHC4) provides information on residual recurrence risk of patients treated with hormone therapies. This study aimed to independently investigate the validity of the IHC4 algorithm for residual risk prediction using both conventional (DAB)-IHC and quantitative immunofluorescence (QIF-AQUA). Methods: The TEAM pathology study recruited >4500 samples from patients treated in the TEAM trial. TMAs were stained for ER, PgR, HER2 and Ki67 using QIF-AQUA technology or DAB-based immunohistochemistry (DAB-IHC). Central HER2 FISH was performed. Quantitative image analysis was used to generate expression scores that were normalized to produce “IHC4 algorithm” as well as novel algorithm scores.  Algorithm scores were compared with disease recurrence in univariate and multivariate Cox Proportional Hazards models. Results: Both DAB-IHC and QIF-AQUA IHC4 continuous models were significant (P<0.0001) for prediction of disease recurrence with a continuous Hazard Ratio (HR) of 1.011 (1.010 – 1.013) for QIF-AQUA IHC4 versus 1.008 (1.007 – 1.010) for the DAB-IHC IHC4 model using the published IHC4 algorithm (Cuzick et al 2011).  Binning continuous model scores (4 bins) by Kaplan-Meier survival analysis was used to graphically illustrate these effects.  De novo models for both DAB-IHC and QIF-AQUA were also significantly (P<0.0001) predictive of residual risk in early breast cancer. Additionally, all 4 models were independent predictors of recurrence (P<0.0001) with other recognized clinical prognostic factors in multivariate analysis.  Although results from DAB and QIF-AQUA were modestly correlated, the QIF-AQUA model showed enhanced prediction of recurrence in both Cox Proportional Hazards Modeling and C-index calculations. Conclusions: Either conventional DAB or QIF-AQUA methods of IHC provided evidence supporting the clinical utility of IHC4 algorithms in the context of the TEAM study.  With careful standardization, either of these IHC4 assays should be considered for prediction of residual risk in early breast cancer.

Mammostrat as an immunohistochemical multigene assay for prediction of early relapse risk in the TEAM pathology study

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Background: Some postmenopausal patients with hormone sensitive early breast cancer remain at high risk of relapse despite endocrine therapy, and might benefit additionally from adjuvant chemotherapy. The challenge is to prospectively identify such patients. The Mammostrat test uses five immunohistochemical markers to stratify patients regarding recurrence risk, and may inform treatment decisions. We tested the efficacy of this panel in the TEAM trial. Methods: Pathology blocks from 4598 TEAM patients were collected and TMAs constructed. The cohort was 47% node positive and 36% were also treated with adjuvant chemotherapy. Triplicate 0.6mm2 TMA cores were stained and positivity for p53, HTF9C, CEACAM5, NDRG1, SLC7A5 assessed. Cases were assigned a Mammostrat risk score, and distant relapse free (DRFS) and disease free survival (DFS) analysed. Results: In multivariate regression analyses, corrected for conventional clinicopathological markers, Mammostrat provided significant additional information on DRFS after endocrine therapy in ER positive node negative patients (N=1226) not receiving chemotherapy (p=0.004). Further analyses in all patients not exposed to chemotherapy, irrespective of nodal status (N=2559) and in the entire cohort (N=3837) showed Mammostrat scores provide additional information on DRFS in these groups (p=0.001 and p<0.0001 respectively; multivariate analyses). No differences were seen between the two endocrine treatment regimens. Conclusions: The Mammostrat score predicts DRFS for both exemestane and tamoxifen-exemestane treated patients irrespective of nodal status and chemotherapy. The ability of this test to provide additional outcome data following treatment provides further evidence for its’ utility in risk stratification of ER positive postmenopausal breast cancer patients.

P5-01-01: Identification, Validation and Assessment of Transcriptional Relevance of a PDGFR-Activation Signature in (Inflammatory) Breast Cancer

Introduction. Breast cancer can be divided into several subgroups characterized by unique patterns of pathway activation. Platelet-derived growth factor receptor (PDGFR) signalling has not yet been included in this classification scheme, although it has been reported to be a potential target for therapy. In this study, we have constructed a PDGFR-activation signature and investigated its relevance in breast cancer.

Materials and Methods. Sixteen PDGFR-modulated genes were identified by intersecting two published PDGFR-modulated gene lists. The resulting gene signature was applied onto a publicly available gene expression data set of GIST (GSE17743) using principle component analysis. The segregation of PDGFR- and KIT-mutated GIST samples was investigated using permutation analysis and classification sensitivity and specificity were assessed. Using the regression coefficients from the first principal component, a PDGFR-activation score was constructed and applied onto a second data set in order to validate the score (GSE1923). Finally, the score was applied onto a gene expression data set of 389 breast cancer ***samples, including 137 samples from patients with IBC.

Results. Sixteen PDGFR-modulated genes (NR4A1, EGR3, JUNB, IER3, TIEG, JUN, BCL3, MYC, NR4A3, PLAU, MCL1, DUSP1, DUSP5, DUSP6, SGK, GADD45A) were able to discriminate PDGFR-mutated GIST samples from KIT-mutated GIST samples with a sensitivity of 75% and a specificity of 85%. Application of the PDGFR-activation score onto a data set of control and PDGF-treated glioblastoma cells showed a significant increase in the PDGFR-activation score in the treated condition (P=0.0302). Application of the PDGFR-signature onto our series of IBC and nIBC samples demonstrated a significant and molecular subtype-independent increase in PDGFR-activation in IBC (P=0.0015; FDR=3%). In addition, in our series of nIBC samples only, PDGFR-activation was associated with decreased DMFS and RFS (P=0.0038 and P=0.0137 respectively). In fact, PDGFR-activation was an independent prognosticator in a multivariate model incorporating the molecular subtypes.

Discussion. We identified a gene signature composed of 16 genes able to predict PDGFR-activation in tissue samples by gene expression analysis. PDGFR-activation is significantly increased in samples from patients with IBC, an aggressive form of locally advanced breast cancer. In addition, in nIBC, PDGFR-activation is associated with DMFS and RFS, independently of the molecular subtypes suggesting that PDGFR-activation might add another level of clinically relevant heterogeneity in breast cancer.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-01-01.

P5-23-06: Monitoring of Quality Indicators Should Lead to Quality Measures. A Dynamic Clinical Pathway for the Treatment of Patients with Early Breast Cancer Is a Tool for Better Cancer Care: Implementation and Prospective Analysis between 2002–2010

Aim: To describe the effects of the development, implementation and prospective systematic evaluation and adaptation of a clinical care pathway for the management of patients with early breast cancer between 2002 and 2010) in a single breast unit.

Materials and methods: In 2002 a clinical pathway was developed by the multidisciplinary breast team of the Sint Augustinus Hospital for de diagnosis and treatment of patients with operable breast cancer. Performance measurements were documented systematically by care providers using an order communication, planning and result reporting system. Annual analysis of predefined clinical outcome measures and indicators was performed. Based on these data and evidence based guidelines the pathway was regularly adapted to improve patient care. Results: The annual number of patients included in the pathway (289 vs 390, p 0.01) ), proportion of patients with Tis-T1 tumors (42% vs 58 %, p 0.01), negative lymph nodes (44% vs 58%, p &lt; 0.01)) and no metastases at diagnosis (91.5% vs 95.9%) has risen significantly between 2002 and 2010. Histological subtypes remained the same. The average length of hospital stay (7.0 days vs 4.1 days, p 0.01) nearly halved and the proportion of breast conserving surgery (BCS) (43% vs 57%), preoperative guide wire localization (14% vs 27%) for impalpable lesions and use of sentinel node biopsy (0% vs 49%) increased significantly (p 0.01). Evolution of quality indicators defined by Eusoma (www.eusomadb.org/indicators.htm) between 2002 and 2010 shows a significant improvement of cancer care: proportion of positive of preoperative histologic diagnosis (59.7% vs 88.4%, p 0.001), more then 9 lymph nodes removed when axillary clearance performed (85.6 vs 91.4%, p&lt; 0.04), BCS for invasive carcinoma up to 3 cm (62.0% vs 82.6%, p 0.016), BCS for DCIS up to 20 mm (43.8% vs 78.6%, p 0.016), hormone therapy in endocrine sensitive tumor (84.8% vs 97.4%, p 0.002), adjuvant chemotherapy in ER negative (PT1c or N+) invasive carcinoma (72% vs 95.6% p 0.028), proportion of second surgery (25% vs 10%, p 0.001) and clear margins after last operation (95% vs 99%, p 0.02). All mandatory EUSOMA requirements were fulfilled in 2010. Patient satisfaction improved significantly over the years (13/19 measured parameters p &lt;0.05 between 2002–2010). Progression free 4 year survival was significantly higher for all patients, for T1 tumors only and for T2-T4 tumors only, treated in 2006–2008 compared to 1999–2002 and 2003–2005 (respectively p 0.006, p 0.05, p 0.06). Overall 4 year survival of the entire M0 population treated in 2006–2008 was significantly better (p 0.05)

Conclusion: Although the patient characteristics changed over the years due to better screening, this clinical pathway for the treatment of patients operable breast cancer proved to be an important tool to improve the quality of patient care and patient satisfaction. Better adherence to guidelines and constant feedback of treatment data to the breast team contributes to a superior patient outcome. Measuring quality indicators proved useful to develop quality measures improving patient care.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-23-06.

P5-14-14: The Presence of a Fibrotic Focus Adds Significant Prognostic Information to the Prognostic 76-Gene Relapse Score in Lymph Node Negative Breast Cancer

Introduction: The fibrotic focus (FF) is a practical, easily assessable and reproducible integrative histological prognostic parameter in breast cancer. Its prognostic value has been shown before (Van den Eynden et al. Histopathology 2007). In this study we investigated whether the assessment of the FF adds prognostic information to the relapse score based on gene expression analysis of 76 genes as previously described (Wang et al. Lancet 2005).

Materials and Methods: All patients of 2 previous prognostic breast cancer gene expression studies for whom FFPE slides of the tumor were available (Wang et al. Lancet 2005 and Yu et al. BMC Cancer 2007) were selected, leading to a study population of 176 lymph node negative breast cancer patients. The presence and size (&lt;1/3 or &gt;1/3 of tumor area) of a FF were assessed on standard HE slides. These data were compared to the 76-gene relapse score, to standard clinicopathological variables and to metastasis-free survival.

Results: A small and large FF were found in 31 (17.6%) and 20 (11.4%) of patients, respectively. In 120 (68.2%) patients there was no FF and in 5 patients the presence of a FF could not be assessed due to insufficient FFPE material. 64 (36.4%) and 112 (63.6%) patients had respectively a good and poor prognostic 76-gene relapse score. There was a significant correlation between the presence of a FF and a poor 76-gene relapse score, 18 of 20 patients with a large FF had a poor relapse score (p = 0.03). Patients with a tumor with a FF and especially with a large FF had a significantly reduced metastasis free survival (Log rank p&lt;0.001). The same was true for patients with a poor 76-gene relapse score (Log rank p&lt;0.001). When only patients with a poor relapse score were taken into account, patients with a tumor with a large FF had a significantly decreased metastasis-free survival compared to patients without a FF or with a small FF (Log rank p=0.005). In patients with a good relapse score, the number of patients with a FF was too small for a separate analysis. In a multivariate Cox regression model for metastasis-free survival including age, ER and PR status, T stage, the FF and the 76-gene relapse score status, the FF (OR 1.5, p=0.02) and the relapse score status (OR 3.4, p = 0.001) were significant independent prognostic factors. Comparable results were found if the presence of a FF was dichotomized in large FF versus no or a small FF.

Conclusion: The assessment of the presence and size of a FF adds independent significant prognostic information to the prognostic 76-gene expression signature, especially in selecting a subgroup of patients with a very poor prognosis. Since the assessment of the FF is practical, easy, reproducible and cheap it should be considered to become part of the standard pathological examination of breast cancer resection specimens.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-14-14.

A phase II study of the combination of endocrine treatment and bortezomib in patients with endocrine-resistant metastatic breast cancer

The majority of patients with hormone receptor-positive metastatic breast cancer die from disease progression despite different types of anti-hormonal treatments. Preclinical studies have indicated that resistance to anti-hormonal therapies may be the result of an activated NF-κB signalling pathway in breast cancer. Bortezomib is a proteasome inhibitor that blocks the NF-κB pathway. Recent pharmacodynamic and pharmaco-kinetic xenograft studies have shown that drug exposure may be a crucial factor for the efficacy of bortezomib in solid tumours. The aim was to investigate whether the addition of bortezomib to anti-hormonal therapy would result in regained antitumour activity in patients with progressive and measurable disease being treated with an endocrine agent. Clinical benefit was defined as patients obtaining stable disease, partial response or complete response after 2 cycles, lasting for at least another five weeks. Bortezomib was administered on days 1, 8, 15 and 22 of a 5-week regimen (1.6 mg/m2). Eight patients received an aromatase inhibitor and bortezomib, while one received tamoxifen and bortezomib. There were 3 grade 3 gastrointestinal toxicities. Median time to treatment failure was 69 days (range, 35-140). Two out of the 9 patients had stable disease for more than 10 weeks. Despite an effective target inhibition, suggested in peripheral blood mononuclear cells and available tumour samples, no objective antitumour responses were observed. Addition of a proteasome inhibitor to anti-hormonal therapy resulted in a clinical benefit rate of 22% in a limited number of patients with endocrine resistant and progressive metastatic breast cancer. The demonstrated proteasome inhibition in tumour tissue provides evidence that the lack of clinical responses is not attributed to deficient drug exposure.

Effect of trabectedin on the QT interval in patients with advanced solid tumor malignancies

PURPOSE

The primary objective of this study was to access the potential effects of trabectedin on the QT/QTc interval in patients with locally advanced or metastatic solid tumors.

METHODS

Patients (n = 75) who had received ≤3 previous lines of chemotherapy and had either relapsed or had progressive disease were enrolled. Patients were administered 3-h intravenous infusions of placebo (saline) on day 1 and trabectedin (1.3 mg/m(2)) on day 2. Time-matched serial triplicate ECG recordings and pharmacokinetic blood samples were collected over 24 h on both days. Heart rate corrected mean QT intervals and changes from predose baseline in QTc (ΔQTc) were assessed. The difference in ΔQTc between trabectedin and placebo was calculated at each time point (ΔΔQTc).

RESULTS

The upper limits of the 90% confidence interval for ΔΔQTcF and ΔΔQTcB at all time points were less than the prespecified noninferiority margin of 10 ms (≤6.65 ms). No patient had a QTc > 500 ms or a time-matched increase from baseline in QTc > 60 ms at any time point. Regression analyses indicated ΔΔQTc was poorly correlated with trabectedin concentration. No adverse events suggestive of proarrhythmic potential were reported.

CONCLUSION

Trabectedin did not prolong the QTc interval. Safety and pharmacokinetic profiles of trabectedin were similar to that observed in other ovarian and breast cancer studies.

Abstract P3-02-05: Evaluation of Gene Transcripts in Primary Tumors at Time of Diagnosis and Circulating Tumor Cells (CTCs) at Time of Metastatic Disease

Introduction: The enumeration of CTCs has already shown to bear clinical relevance as a prognostic and predictive factor in metastatic breast cancer. In addition to enumeration, isolation of CTCs enables their molecular characterization and thus holds great promise to establish association of their genetic profile with patient outcome and to identify potential drugable targets. In this study we established epithelial-specific mRNA and microRNA profiles in CTCs of patients with metastatic breast cancer, compared these profiles to the profiles measured in corresponding primary tumors, and determined their association with clinical parameters.

Study design:

For this study we included 50 breast cancer patients, of which 32 presented themselves with over 5 CTCs at the time of metastatic disease. From 14 of these patients with more than 5 CTCs at the time of metastatic disease also the primary tumor at time of breast cancer diagnosis was evaluated. Total RNA was extracted 1) from blood of the 50 patients with metastatic disease after EpCAM-based enrichment of 7.5 mL whole blood with the CellSearch™ Profile Kit [Veridex LCC], 2) from 14 unprocessed whole blood preparations from healthy blood donors, and 3) from 14 primary tumors. Gene transcript levels of CTC-specific and potentially clinically relevant mRNAs and microRNAs were compared in CTCs isolated at time of metastatic disease and the corresponding primary tumors. In addition, the association of these transcript levels with clinical data was assessed.

Results:

We identified 24 mRNA and 14 microRNAs more abundantly expressed in CellSearch-enriched fractions from patients with at least 5 CTCs compared with those without CTCs and/or compared with unprocessed whole blood prior to CellSearch enrichment (Mann-Whitney U-test P&lt;0.05). In addition, when comparing transcript levels present in CTCs during metastatic disease and those measured in the corresponding primary tumor, potentially clinically relevant discrepancies were observed. Findings of interest included changes in transcript levels of genes such as ESR1, ERBB2, TOP2A and MGB1, and in genes associated with proliferation and EMT. Finally, associations were observed between transcript levels measured in CTC preparations and clinical data like nodal status and size of the primary tumor.

Conclusion:

Our results show that molecular characterization of CTCs is feasible and has potential for a more tailored clinical approach above CTC enumeration in the treatment of metastatic breast cancer patients.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-02-05.

International expert panel on inflammatory breast cancer: consensus statement for standardized diagnosis and treatment

BACKGROUND

Inflammatory breast cancer (IBC) represents the most aggressive presentation of breast cancer. Women diagnosed with IBC typically have a poorer prognosis compared with those diagnosed with non-IBC tumors. Recommendations and guidelines published to date on the diagnosis, management, and follow-up of women with breast cancer have focused primarily on non-IBC tumors. Establishing a minimum standard for clinical diagnosis and treatment of IBC is needed.

METHODS

Recognizing IBC to be a distinct entity, a group of international experts met in December 2008 at the First International Conference on Inflammatory Breast Cancer to develop guidelines for the management of IBC.

RESULTS

The panel of leading IBC experts formed a consensus on the minimum requirements to accurately diagnose IBC, supported by pathological confirmation. In addition, the panel emphasized a multimodality approach of systemic chemotherapy, surgery, and radiation therapy.

CONCLUSIONS

The goal of these guidelines, based on an expert consensus after careful review of published data, is to help the clinical diagnosis of this rare disease and to standardize management of IBC among treating physicians in both the academic and community settings.

The presence of circulating total DNA and methylated genes is associated with circulating tumour cells in blood from breast cancer patients

Circulating tumour cells (CTC) and tumour-related methylated DNA in blood have been separately assessed for their utility as a marker for subclinical metastasis in breast cancer. However, no studies have looked into the relation between the both molecular markers in this type of cancer. In this study, we investigated the correlations between total/methylated DNA and CTC in the blood from metastatic breast cancer patients. We simultaneously obtained whole blood, plasma and serum samples from 80 patients and 20 controls. The CellSearch System was used to enumerate CTC in blood samples. Plasma total DNA levels were determined by a QPCR method. Sera were analysed by methylation-specific QPCR for three markers: adenomatous polyposis coli (APC), ras association domain family protein 1A (RASSF1A) and oestrogen receptor 1 (ESR1). Total DNA levels in patients were significantly increased when compared with controls (P<0.001) and correlated with the number of CTC (r=0.418, P<0.001). Hypermethylation of one or more genes was detected in 42 (53%) serum samples from breast cancer patients and in three (16%) serum samples from controls (P=0.003). APC was hypermethylated in 29%, RASSF1A in 35% and ESR1 in 20% of breast cancer cases. Detection of a methylated gene in serum was associated with the detection of CTC in blood (P=0.03). The detection of large amounts of circulating total/methylated DNA correlated with the presence of CTC in the blood from patients with breast cancer. This can be interpreted in two ways: (a) CTC are a potential source of circulating tumour-specific DNA; (b) high numbers of CTC and circulating methylated DNA are both a phenotypic feature of more aggressive tumour biology.

The VEGF pathway and the AKT/mTOR/p70S6K1 signalling pathway in human epithelial ovarian cancer

Vascular endothelial growth factor (VEGF)-A inhibitors exhibit unseen high responses and toxicity in recurrent epithelial ovarian cancer suggesting an important role for the VEGF/VEGFR pathway. We studied the correlation of VEGF signalling and AKT/mTOR signalling. Using a tissue microarray of clinical samples (N=86), tumour cell immunohistochemical staining of AKT/mTOR downstream targets, pS6 and p4E-BP1, together with tumour cell staining of VEGF-A and pVEGFR2 were semi-quantified. A correlation was found between the marker for VEGFR2 activation (pVEGFR2) and a downstream target of AKT/mTOR signalling (pS6) (R=0.29; P=0.002). Additional gene expression analysis in an independent cDNA microarray dataset (N=24) showed a negative correlation (R=−0.73, P<0.0001) between the RPS6 and the VEGFR2 gene, which is consistent as the gene expression and phosphorylation of S6 is inversely regulated. An activated tumour cell VEGFR2/AKT/mTOR pathway was associated with increased incidence of ascites (χ², P=0.002) and reduced overall survival of cisplatin–taxane-based patients with serous histology (N=32, log-rank test, P=0.04). These data propose that VEGF-A signalling acts on tumour cells as a stimulator of the AKT/mTOR pathway. Although VEGF-A inhibitors are classified as anti-angiogenic drugs, these data suggest that the working mechanism has an important additional modality of targeting the tumour cells directly.

Safety of the anti-IGF-1R antibody CP-751,871 in combination with exemestane in patients with advanced breast cancer

Abstract #2136

Background: Aromatase inhibitors (AIs) are established first-line treatment for postmenopausal estrogen receptor (ER)+ metastatic breast cancer. However, not all patients benefit from AIs and those whose tumors initially respond eventually relapse. One hypothesized mechanism for tumor insensitivity to hormonal agents seems to be cross-talk between the ER pathway and other growth factor signaling pathways, in particular the insulin-like growth factor receptor type 1 (IGF-1R). In xenograft breast cancer models, CP-751,871 administration increased tumor growth inhibition induced by tamoxifen. Thus our trial addresses the effect of combining AI with an IGF-1R antagonist.&#x2028; Methods: A phase II, multicenter, randomized, two-arm, comparative, two-stage trial to determine PFS of CP-751,871, a fully human IgG2 monoclonal antibody targeting IGF-1R, in combination with exemestane versus exemestane alone as first-line treatment in patients with hormone receptor positive, advanced breast cancer. Secondary endpoints include clinical benefit (CR, PR, or SD ≥6 months), safety/tolerability and PK. Patients included in the study are post menopausal, ≥18 years with locally advanced/metastatic breast cancer (stage IIIB or IV), ECOG PS 0–2, and adequate hematological, biochemical, and cardiac functions. CP-751,871 is given by intravenous infusion at a dose of 20 mg/kg every 21 days while 25 mg exemestane was given p.o. daily.&#x2028; Results: To date 37 patients have been dosed with CP-751,871 plus exemestane. Median age is 60.5 years (range 34–84). Patients received a median of 9.5 treatment cycles (range 1–22). One GR 4 CP-751,871-related AE (hoarse voice) was reported, which resolved after 3 days without intervention. GR 3 CP-751,871-related toxicities included 8.1% hyperglycemia (n=3), 8.1% GGT elevation (n=3), 5.4% allergic reaction (n=2), 5.4% hearing loss (n=2), 5.4% weight loss (n=2), and 2.7% anorexia (n=1). GR 2 CP-751,871-related AEs &gt;10% were headaches, muscle cramps, and nail changes. Both hyperglycemia and hypersensitivity reactions were manageable (with oral hypoglycemic drug/insulin and antihistamine), while GGT elevation seems to be reversible.&#x2028; Conclusions: CP-751,871 in combination with exemestane is well tolerated. The most frequent GR 3 side effects are either well managed with medications or appear to be reversible. Therefore, CP-751,871, due to its safety profile, is a good targeted agent to combine with standard hormonal therapy. The stage I portion of the study to determine efficacy and toxicity is ongoing.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2136.

Bortezomib/docetaxel combination therapy in patients with anthracycline-pretreated advanced/metastatic breast cancer: a phase I/II dose-escalation study

The aim of this study was to determine the dose-limiting toxicities (DLTs) and maximum tolerated dose (MTD) of bortezomib plus docetaxel in patients with anthracycline-pretreated advanced/metastatic breast cancer. Forty-eight patients received up to eight 21-day cycles of docetaxel (60-100 mg m(-2) on day 1) plus bortezomib (1.0-1.5 mg m(-2) on days 1, 4, 8, and 11). Pharmacodynamic and pharmacokinetic analyses were performed in a subset of patients. Five patients experienced DLTs: grade 3 bone pain (n=1) and febrile neutropenia (n=4). The MTD was bortezomib 1.5 mg m(-2) plus docetaxel 75 mg m(-2). All 48 patients were assessable for safety and efficacy. The most common adverse events were diarrhoea, nausea, alopecia, asthenia, and vomiting. The most common grade 3/4 toxicities were neutropenia (44%), and febrile neutropenia and diarrhoea (each 19%). Overall patient response rate was 29%. Median time to progression was 5.4 months. In patients with confirmed response, median time to response was 1.3 months and median duration of response was 3.2 months. At the MTD, response rate was 38%. Pharmacokinetic characteristics of bortezomib/docetaxel were comparable with single-agent data. Addition of docetaxel appeared not to affect bortezomib inhibition of 20S proteasome activity. Mean alpha-1 acid glycoprotein concentrations increased from baseline at nearly all time points across different bortezomib dose levels. Bortezomib plus docetaxel is an active combination for anthracycline-pretreated advanced/metastatic breast cancer. The safety profile is manageable and consistent with the side effects of the individual agents.

Treatment of advanced hormone-sensitive breast cancer in postmenopausal women with exemestane alone or in combination with celecoxib

PURPOSE

Preclinical data showed that the combination of exemestane and celecoxib has synergistic effects. Therefore, a study was undertaken to explore the efficacy and tolerability of this combination in postmenopausal patients with advanced, hormone-sensitive breast cancer.

PATIENTS AND METHODS

A randomized phase II study was conducted in postmenopausal patients with hormone-sensitive breast cancer and measurable disease who had progressive disease after treatment with tamoxifen. Patients were randomly assigned to either exemestane 25 mg daily or the combination of exemestane 25 mg daily with celecoxib 400 mg twice daily. Response Evaluation Criteria in Solid Tumors Group criteria were used to determine antitumor efficacy. Primary end point was the rate of clinical benefit. Secondary end points were tolerability, objective response rate, time to progression (TTP), and duration of clinical benefit. A pharmacodynamic and a pharmacokinetic study were conducted in parallel.

RESULTS

One hundred eleven patients (exemestane, n = 55; combination, n = 56) were enrolled in 2002. The demographic characteristics and prognostic factors were similar in both arms. In the assessable population, 24 of 51 patients in the combination arm and 24 of 49 patients in the exemestane arm achieved clinical benefit. TTP was similar in both groups. Duration of clinical benefit was longer in the combination group (median, 96.6 v 49.1 weeks). The addition of celecoxib did not change the tolerability profile of exemestane alone.

CONCLUSION

Similar rates of clinical benefit were achieved in both groups.

Comparison of molecular determinants of angiogenesis and lymphangiogenesis in lymph node metastases and in primary tumours of patients with breast cancer

Angiogenesis and lymphangiogenesis are complex processes, driven by multiple factors. In primary breast tumours (PTs), VEGFA, -C and -D are the most important (lymph)angiogenic factors. The induction of lymphangiogenesis in axillary lymph node (LN) metastases of patients with breast cancer was described recently. To compare the molecular determinants of (lymph)angiogenesis in LN metastases and PTs of breast cancer patients, RNA was isolated from formalin-fixed, paraffin-embedded tissue sections of a metastatically involved and uninvolved LN and the PT from 26 lymph node-positive patients. The expression of 12 (lymph)angiogenic markers was measured by qRT-PCR. Expression was correlated with tumour cell proliferation, angiogenesis and lymphangiogenesis, quantified by tumour cell proliferation fraction (TCP%) and (lymphatic) endothelial cell proliferation fraction [(L)ECP%]. TCP%, ECP% and LECP% were assessed on immunohistochemical double stains for CD34/Ki-67 and D2-40/Ki-67, respectively. In involved LNs, the relative gene expression levels of PROX1 (p < 0.001) and FGF2 (p = 0.008) were decreased and the expression levels of VEGFA (p = 0.01) and PDGFB (p = 0.002) were increased compared to uninvolved LNs. The expression of most markers was increased in PTs compared to involved LNs. In metastatically involved LNs, the expression of VEGFA correlated with ECP% (r = 0.54, p = 0.009) and LECP% (r = 0.76, p < 0.001). In PTs, VEGFA correlated only with ECP% (r = 0.74, p < 0.001). VEGFD correlated with peritumoural LECP% (r = 0.61, p = 0.001) and with VEGFC (r = 0.78, p < 0.001). Linear regression analysis confirmed the expression of VEGFA as an independent predictor of ECP% in both PTs and LN metastases and of LECP% in LN metastases. The expression of VEGFD, but not of VEGFA, independently predicted peritumoural LECP% in PTs. Our results confirm existing data that, in PTs, angiogenesis and lymphangiogenesis are respectively driven by VEGFA and VEGFD. In contrast, in LN metastases, both processes seem to be driven by VEGFA. Lymphangiogenesis in PTs and in LN metastases might thus be driven by different factors.

A fibrotic focus is a prognostic factor and a surrogate marker for hypoxia and (lymph)angiogenesis in breast cancer: review of the literature and proposal on the criteria of evaluation

A fibrotic focus is a scar-like area in the centre of a carcinoma and can be regarded as a focus of exaggerated reactive tumour stroma formation. Although modern surgical pathology uses different histopathological and molecular markers to assess the aggressiveness and predict the behaviour of malignant tumours, markers reflecting stromal cell behaviour and interactions between epithelial cells and stromal cells are scarce. In this review we summarize all studies investigating the value of a fibrotic focus as a prognostic factor and as a surrogate marker for hypoxia and (lymph)angiogenesis in patients with breast cancer. These data show that a fibrotic focus can be used as a practical, easily assessable and reproducible integrative histological prognostic parameter in breast cancer. We propose a consensus methodology to assess the fibrotic focus in breast cancer.

NF-kappaB activation in inflammatory breast cancer is associated with oestrogen receptor downregulation, secondary to EGFR and/or ErbB2 overexpression and MAPK hyperactivation

Activation of NF-κB in inflammatory breast cancer (IBC) is associated with loss of estrogen receptor (ER) expression, indicating a potential crosstalk between NF-κB and ER. In this study, we examined the activation of NF-κB in IBC and non-IBC with respect to ER and EGFR and/or ErbB2 expression and MAPK hyperactivation. A qRT–PCR based ER signature was evaluated in tumours with and without transcriptionally active NF-κB, as well as correlated with the expression of eight NF-κB target genes. Using a combined ER/NF-κB signature, hierarchical clustering was executed. Hyperactivation of MAPK was investigated using a recently described MAPK signature (Creighton et al, 2006), and was linked to tumour phenotype, ER and EGFR and/or ErbB2 overexpression. The expression of most ER-modulated genes was significantly elevated in breast tumours without transcriptionally active NF-κB. In addition, the expression of most ER-modulated genes was significantly anticorrelated with the expression of most NF-κB target genes, indicating an inverse correlation between ER and NF-κB activation. Clustering using the combined ER and NF-κB signature revealed one cluster mainly characterised by low NF-κB target gene expression and a second one with elevated NF-κB target gene expression. The first cluster was mainly characterised by non-IBC specimens and IHC ER+ breast tumours (13 out of 18 and 15 out of 18 respectively), whereas the second cluster was mainly characterised by IBC specimens and IHC ER− breast tumours (12 out of 19 and 15 out of 19 respectively) (Pearson χ², P<0.0001 and P<0.0001 respectively). Hyperactivation of MAPK was associated with both ER status and tumour phenotype by unsupervised hierarchical clustering using the MAPK signature and was significantly reflected by overexpression of EGFR and/or ErbB2. NF-κB activation is linked to loss of ER expression and activation in IBC and in breast cancer in general. The inverse correlation between NF-κB activation and ER activation is due to EGFR and/or ErbB2 overexpression, resulting in NF-κB activation and ER downregulation.

First international consensus on the methodology of lymphangiogenesis quantification in solid human tumours

The lymphatic system is the primary pathway of metastasis for most human cancers. Recent research efforts in studying lymphangiogenesis have suggested the existence of a relationship between lymphatic vessel density and patient survival. However, current methodology of lymphangiogenesis quantification is still characterised by high intra- and interobserver variability. For the amount of lymphatic vessels in a tumour to be a clinically useful parameter, a reliable quantification technique needs to be developed. With this consensus report, we therefore would like to initiate discussion on the standardisation of the immunohistochemical method for lymphangiogenesis assessment.

Induction of lymphangiogenesis in and around axillary lymph node metastases of patients with breast cancer

We studied the presence of lymphangiogenesis in lymph node (LN) metastases of breast cancer. Lymph vessels were present in 52 of 61 (85.2%) metastatically involved LNs vs 26 of 104 (25.0%) uninvolved LNs (P<0.001). Furthermore, median intra- and perinodal lymphatic endothelial cell proliferation fractions were higher in metastatically involved LNs (P<0.001). This is the first report demonstrating lymphangiogenesis in LN metastases of cancer in general and breast cancer in particular.