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<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.

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.

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.

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.

Bevacizumab in the treatment of patients with advanced breast cancer: where have we landed?

Vast preclinical and clinical evidence has made angiogenesis one of the hallmarks of cancer. In many human tumours, vascular endothelial growth factor (VEGF) has been identified as the crucial mediator of this process. Initial studies suggested that angiogenesis, and VEGF in particular, could be inhibited without the risk of major side effects. After the pivotal data in first-line studies in patients with colorectal cancer, numerous clinical trials have been undertaken in patients with breast cancer. This review attempts to update these investigations and define the role of anti-VEGF antibody treatment in advanced breast cancer.

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.

Circulating tumor cell detection: A direct comparison between the CellSearch System, the AdnaTest, and CK-19/mammaglobin RT-PCR in patients with metastatic breast cancer

e22117

Background: The detection, enumeration and isolation of circulating tumor cells (CTC) has considerable potential to influence the clinical management of patients with breast cancer. There is however a substantial variability in the rates of positive samples using existing detection techniques. Methods: This study was designed to compare three techniques for detecting CTC in blood of 80 patients with metastatic breast cancer (MBC) and 20 healthy controls: the CellSearch System, which is an automated, standardized and regulatory-approved system for the immunocytochemical detection and quantification of CTC in blood; ii) the AdnaTest Breast Cancer Select/Detect, which involves the detection of tumor-associated transcripts by RT-PCR after an immunomagnetically enrichment of tumor cells; iii) an in-house developed multimarker qRT-PCR assay, which involves the quantification of tumor-associated transcripts (CK-19 and MAM) by qRT- PCR. Results: As a result, 23% of patients with MBC were positive by the CellSearch System (≥5 CTC), 22% by the AdnaTest (>0.30 ng/μl for any of the amplicons), 31% by qRT-PCR for CK-19 and 49% by qRT-PCR for MAM. Samples were more likely to be positive by qRT-PCR for at least one mRNA marker than by the CellSearch System (P<0.001) or the AdnaTest (P <0.001). The concordance between samples analyzed by the CellSearch System and the AdnaTest was substantial (κ = 0.667, P <0.001). Agreement between both detection techniques was observed in 88% of blood samples. When the CellSearch System was compared with the qRT-PCR assays for CK-19 and MAM, we observed agreement percentages of 78% and 58%, respectively (κ = 0.462, P <0.001 and κ = 0.159, P = 0.09). Agreement between the AdnaTest and the qRT-PCR assays for CK-19 and MAM was observed in 78% and 53% of blood samples, respectively (κ = 0.443, P <0.001 and κ = 0.05, P = 0.607). Conclusions: We observed a substantial variation in the detection rates of CTC in blood from MBC patients using three different techniques. A higher rate of positive samples was observed using a combined qRT-PCR approach for CK-19 and MAM, which suggests that this is currently the most sensitive technique for detecting CTC.

No significant financial relationships to disclose.

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.

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.

Phase II study of docetaxel, carboplatin and trastuzumab (THC) in patients with locally advanced breast cancer

1062

Background: Preclinical and clinical data suggest that docetaxel, trastuzumab and platinum compounds act synergistically. Studies in the metastatic disease are conflicting. In this phase II study the activity of this regimen was assessed and correlated with changes in circulating biomarkers. Methods: Patients with locally advanced, FISH+ HER2 amplified, breast cancer were treated in this protocol with TCH as initial neo-adjuvant treatment. Patients received Docetaxel 75 mg/sqm, carboplatinum AUC 6mg/mL.min and trastuzumab 6 mg/kg (with a loading dose in cycle 1). Six cycles were intended provided no progression occured. No prophylactic G-CSF or antibiotics were administered. Measurement of circulating ECD HER2, CTC (RT-PCR mammaglobin and CK-19), and total plasma DNA was performed prior to the start of therapy, after cycle 1 and after 3 and 6 cycles. A cardiac MUGA exam was performed every three cycles. All patients were intented to undego mastectomy and axillary clearance after the end of chemotherapy. Results: 40 patients have been treated with a median age of 56 year. No patient suffered from progression of disease while on THC. All patients received 6 cycles, 4 patients received respectively 7, 7, 8 and 9 cycles. In total 247 cycles were administered. No cases of CHF were observed. 5 patients suffered from a asymptomatic decline > 10% in LVEF. A clinical CR and PR was obtained in 32 (80%). A pathological CR both in breast axilla was obtained in 16/39 (41%). Tumor response was predicted by changes in both CTC and ECD HER-2. Conclusions: THC was confirmed to be a very active and safe regimen in patients with HER-2 amplified breast cancer. Changes in biomarkers rapidly predicted response.

No significant financial relationships to disclose.

Confirmation of the distinct molecular phenotype of inflammatory breast cancer compared to non-inflammatory breast cancer using Affymetrix-based genome-wide gene expression analysis

21055

Background: We have shown with cDNA microarrays that inflammatory breast cancer (IBC) and non-IBC are distinct biological entities. The purpose of this study was to confirm our previous results using Affymetrix chips. Methods: RNA was extracted from 19 IBC samples and 42 non-stage matched non-IBC samples. RNA was hybridized onto Affymetrix HG U133 Plus 2.0 chips. Gene expression data were normalized using GCRMA and genes with a gene expression of at least 250 in 50% of the cases were filtered in. Hierarchical clustering and principle component analysis was executed. Identification of the different cell-of-origin subtypes in our expression data set was done using the intrinsic gene list. A NFkB signature, a MAPK signature and our own IBC signature were tested by clustering analysis. Results: Clustering using 11341 genes resulted in the identification of two clusters: one containing 14/19 IBC samples and a second containing 32/42 non-IBC (Pearson χ2; p<0.0001). Principle component analysis separated IBC from non-IBC samples along the first principle component. Interestingly, IBC samples more closely resemble T1 - T2 tumours than T3 - T4 tumours. Application of the intrinsic gene set to our IBC/non-IBC data set resulted in the classification of 14/19 IBC samples as basal-like or ErbB2-overexpressing tumours compared to only 4/42 non-IBC tumours (Pearson χ2; p<0.0001). Our own IBC signature was confronted with the new data set and performed well in separating IBC specimens form non-IBC specimens. Clustering identified three clusters from which one cluster contained 18 samples, including 12 IBC specimens (p<0.0001). Using the NFkB and MAPK signatures, similar results were obtained. Conclusions: These results confirm our findings that IBC is a distinct biologic phenotype, characterized by activation of NFkB, possibly through activation of MAPK's. IBC tumours more often demonstrate characteristics from basal-like and ErbB2-overexpressing breast tumours. The fact that IBC tumours are rapidly developing tumours instead of longstanding tumourigenic processes might explain the close resemblance of the IBC gene expression profile to the gene expression profile of T1 and T2 tumours.

No significant financial relationships to disclose.

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

16081

Background: The Akt/mTOR/p70S6K1 (Amp) pathway is activated in a proportion of epithelial ovarian cancers. The ribosomal protein pS6 and p4EBP1 are downstream targets and presumed representative for the pathway's activity. VEGF and angiogenesis in ovarian cancer play an important role as bevacizumab induces high response rates and prolongs progression-free survival in women with relapsed ovarian cancer in two phase II trials. The Amp pathway has proven to be correlated with HIF1alfa and VEGF A expression in vitro. Material and Methods: Our primary objective was to evaluate correlation between this pathway in human subject tissues and angiogenesis using VEGF A and pVEGFR2. Our second objective was to evaluate if different metastatic abdominal (peritoneal and/or omental) lesions show the same pathway hyperactivity and/or angiogenesis as the primary tumour, because relapses usually involve metastatic abdominal lesions. Epithelial ovarian cancer paraffin imbedded material from 1999–2004 was collected. A tissue micro array was build with three samples per paraffin block. Immunohistochemical staining was performed using pS6, p4EBP1, pAKT, VEGF and pVEGFR2. Results: 89 patients were collected with a median age of 69.8y. Patients were FIGO stage I in 21%, stage II in 4%, stage III in 62% and 11% stage IV. Histological examination showed in 53% serous papillary tumours, 25.8% endometroid tumours, clear cell carcinoma in 11.2% and mucinous tumours in 4.5%. 65 patients had available tissue material of both primary tumour as well as other (multiple) metastatic abdominal disease tissue. The results of the immunohistochemical staining as well as the correlation analysis will be presented. Conclusion: Although anti-angiogenesis seems to be very active against human epithelial ovarian cancer, it is at present associated with unacceptable treatment induced toxicities. Inhibiting the Amp pathway with mTOR inhibitors could potentially also inhibit angiogenesis in ovarian cancer with the potential of more manageable side effects. This study will provide some evidence on the relationship between the Amp pathway and the VEGF pathway in human epithelial ovarian cancer.

No significant financial relationships to disclose.

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.

Distinguishing blood and lymph vessel invasion in breast cancer: a prospective immunohistochemical study

Recently, peritumoural (lympho)vascular invasion, assessed on haematoxylin-eosin (HE)-stained slides, was added to the St Gallen criteria for adjuvant treatment of patients with operable breast cancer (BC). New lymphatic endothelium-specific markers, such as D2-40, make it possible to distinguish between blood (BVI) and lymph vessel invasion (LVI). The aim of this prospective study was to quantify and compare BVI and LVI in a consecutive series of patients with BC. Three consecutive sections of all formalin-fixed paraffin-embedded tissue blocks of 95 BC resection specimens were (immuno)histochemically stained in a fixed order: HE, anti-CD34 (pan-endothelium) and anti-D2-40 (lymphatic endothelium) antibodies. All vessels with vascular invasion were marked and relocated on the corresponding slides. Vascular invasion was assigned LVI (CD34 [plus sign in circle] or [minus sign in circle]/D2-40 [plus sign in circle]) or BVI (CD34 [plus sign in circle]/D2-40 [minus sign in circle]) and intra- (contact with tumour cells or desmoplastic stroma) or peritumoural. The number of vessels with LVI and BVI as well as the number of tumour cells per embolus were counted. Results were correlated with clinico-pathological variables. Sixty-six (69.5%) and 36 (37.9%) patients had, respectively, LVI and BVI. The presence of 'vascular' invasion was missed on HE in 20% (peritumourally) and 65% (intratumourally) of cases. Although LVI and BVI were associated intratumourally (P=0.02), only peritumoural LVI, and not BVI, was associated with the presence of lymph node (LN) metastases (p(peri)=0.002). In multivariate analysis, peritumoural LVI was the only independent determinant of LN metastases. Furthermore, the number of vessels with LVI was larger than the number of vessels with BVI (P=0.001) and lymphatic emboli were larger than blood vessel emboli (P=0.004). We demonstrate that it is possible to distinguish between BVI and LVI in BC specimens using specific lymphatic endothelium markers. This is important to study the contribution of both processes to BC metastasis. Furthermore, immunohistochemical detection of lymphovascular invasion might be of value in clinical practice.

Real-time RT-PCR detection of disseminated tumour cells in bone marrow has superior prognostic significance in comparison with circulating tumour cells in patients with breast cancer

This study assessed the ability of real-time reverse transcription–polymerase chain reaction (RT–PCR) analysis to detect disseminated epithelial cells (DEC) in peripheral blood (PB) and bone marrow (BM) of patients with breast cancer (BC). Detection of DEC in BM is an obvious choice in BC, but blood sampling is more convenient. The aim of this study was to evaluate whether the detection of DEC in either PB or BM predicts overall survival (OS). Peripheral blood and BM samples were collected from 148 patients with primary (stage M0, n=116/78%) and metastatic (stage M+, n=32/21%) BC before the initiation of any local or systemic treatment. Peripheral blood of healthy volunteers and BM of patients with a nonmalignant breast lesion or a haematological malignancy served as the control group. Disseminated epithelial cells was detected by measuring relative gene expression (RGE) for cytokeratin-19 (CK-19) and mammaglobin (MAM), using a quantitative RT–PCR detection method. The mean follow-up time was 786 days (+/− 487). Kaplan–Meier analysis was used for predicting OS. By taking the 95 percentile of the RGE of CK-19 (BM: 26.3 and PB: 58.7) of the control group as cutoff, elevated CK-19 expression was detected in 42 (28%) BM samples and in 22 (15%) PB samples. Mammaglobin expression was elevated in 20% (both PB and BM) of the patients with BC. There was a 68% (CK-19) and 75% (MAM) concordance between PB and BM samples when classifying the results as either positive or negative. Patients with an elevated CK-19 or MAM expression in the BM had a worse prognosis than patients without elevated expression levels (OS: log-rank test, P=0.0045 (CK-19) and P=0.025 (MAM)). For PB survival analysis, no statistical significant difference was observed between patients with or without elevated CK-19 or MAM expression (OS: log-rank test, P=0.551 (CK-19) and P=0.329 (MAM)). Separate analyses of the M0 and M+ patients revealed a marked difference in OS according to the BM CK-19 or MAM status in the M+ patient group, but in the M0 group, only MAM expression was a prognostic marker for OS. Disseminated epithelial cells, measured as elevated CK-19 or MAM mRNA expression, could be detected in both PB and BM of patients with BC. Only the presence of DEC in BM was highly predictive for OS. The occurrence of DEC in the BM is probably less time-dependent and may act as a filter for circulating BC cells. The use of either larger volumes of PB or performing an enrichment step for circulating tumour in blood cells might improve these results.

Angiogenesis and hypoxia in lymph node metastases is predicted by the angiogenesis and hypoxia in the primary tumour in patients with breast cancer

Hypoxia and angiogenesis are important factors in breast cancer progression. Little is known of hypoxia and angiogenesis in lymph node metastases of breast cancer. The aim of this study was to quantify hypoxia, by hypoxia-induced marker expression levels, and angiogenesis, by endothelial cell proliferation, comparing primary breast tumours and axillary lymph node metastases. Tissue sections of the primary tumour and a lymph node metastasis of 60 patients with breast cancer were immunohistochemically stained for the hypoxia-markers carbonic anhydrase 9 (CA9), hypoxia-inducible factor-1α (Hif-1α) and DEC-1 and for CD34/Ki-67. Endothelial cell proliferation fraction (ECP%) and tumour cell proliferation fraction (TCP%) were assessed. On haematoxylin–eosin stain, the growth pattern and the presence of a fibrotic focus were assessed. Hypoxia-marker expression, ECP% and TCP% in primary tumours and in lymph node metastases were correlated to each other and to clinico-pathological variables. Median ECP% and TCP% in primary tumours and lymph node metastases were comparable (primary tumours: ECP%=4.02, TCP%=19.54; lymph node metastases: ECP%=5.47, TCP%=21.26). ECP% correlated with TCP% (primary tumours: r=0.63, P<0.001; lymph node metastases: r=0.76, P<0.001). CA9 and Hif-1α expression were correlated (primary tumours P=0.005; lymph node metastases P<0.001). In primary tumours, CA9 and Hif-1α expression were correlated with DEC-1 expression (P=0.05), presence of a fibrotic focus (P<0.007) and mixed/expansive growth pattern (P<0.001). Primary tumours and lymph node metastases with CA9 or Hif-1α expression had a higher ECP% and TCP% (P<0.003); in primary tumours, mixed/expansive growth pattern and fibrotic focus were characterised by higher ECP% (P=0.03). Furthermore, between primary tumours and lymph node metastases a correlation was found for ECP%, TCP%, CA9 and Hif-1α expression (ECP% r=0.51, P<0.001; TCP r=0.77, P<0.001; CA9 and Hif-1α P<0.001). Our data demonstrate that the growth of breast cancer lymph node metastases is angiogenesis dependent and that angiogenesis and hypoxia in the primary tumour predict angiogenesis and hypoxia in the lymph node metastases. Together with previous findings in breast cancer liver metastases, which grow in 96% of cases angiogenesis independently, these data suggest that both the intrinsic growth characteristics and angiogenic potential of breast cancer cells and the site-specific tumour microenvironment determine angiogenesis and hypoxia in breast cancer.

Real-time RT-PCR correlates with immunocytochemistry for the detection of disseminated epithelial cells in bone marrow aspirates of patients with breast cancer

Real-time reverse transcriptase–polymerase chain reaction (RT–PCR) is a technique with the potential of improving the quantification of disseminated epithelial cells (DEC) in haematological tissues due to its exquisite sensitivity. This sensitivity may lead to false positivity. Immunocytochemistry (ICC) is regarded as the standard methodology to diagnose DEC. In this study, detection with ICC was compared with quantitative real-time RT–PCR for CK-19 and mammaglobin (hMAM) mRNA in bone marrow (BM) of patients with metastatic breast cancer (MBC). Bone marrow was aspirated from 14 control patients and from 29 patients with MBC. Mononuclear cells (MNC) were isolated. Immunostaining was carried out with the Epimet kit. Quantitative PCR was performed on the ABI Prism 7700. The CK-19 and hMAM mRNA quantities were normalised against β-Actin and calculated relative to a calibrator sample (relative gene expression). All controls were negative by ICC and for hMAM expression measured by RT–PCR, whereas the median RGE value for CK-19 was 0.57. For the MBC patients, the median RGE for hMAM was 0 and 10 out of 25 (40%) tested positive. Median RGE for CK-19 was 2.9 and 20 out of 25 (80%) tested positive. With ICC, the median value was 1 stained cell per sample, and 15 out of 24 (62%) samples were positive. A correlation was observed between CK-19 and hMAM expression (r=0.7; P=0.0003), and between hMAM expression and ICC (r=0.6; P=0.003). CK-19 expression and ICC (r=0.9; P<0.0001) showed the strongest correlation. Reverse transcriptase–polymerase chain reaction for CK-19 resulted in a higher number of positive BM samples of patients with MBC than ICC. Since an excellent correlation is observed between ICC and RT–PCR, and RT–PCR is probably more sensitive with the advantage of being less observer dependent and thus also more easy to automate, we consider our quantitative real-time RT–PCR method as validated for the detection of DEC in the bone marrow of breast cancer patients.