Functional Th1-oriented T follicular helper cells that infiltrate human breast cancer promote effective adaptive immunity

We previously demonstrated that tumor-infiltrating lymphocytes (TIL) in human breast cancer sometimes form organized tertiary lymphoid structures (TLS) characterized by CXCL13-producing T follicular helper (Tfh) cells. The present study found that CD4+ Tfh TIL, CD8+ TIL, and TIL-B, colocalizing in TLS, all express the CXCL13 receptor CXCR5. An ex vivo functional assay determined that only activated, functional Th1-oriented Tfh TIL (PD-1hiICOSint phenotype) provide help for immunoglobulin and IFN-γ production. A functional Tfh TIL presence signals an active TLS, characterized by humoral (immunoglobulins, Ki-67+ TIL-B in active germinal centers) and cytotoxic (GZMB+CD8+ and GZMB+CD68+ TIL plus Th1 gene expression) immune responses. Analysis of active versus inactive TLS in untreated patients revealed that the former are associated with positive clinical outcomes. TLS also contain functional T follicular regulatory (Tfr) TIL, which are characterized by a CD25+CXCR5+GARP+FOXP3+ phenotype and a demethylated FOXP3 gene. Functional Tfr inhibited functional Tfh activities via a glycoprotein A repetitions predominant (GARP)-associated TGF-β-dependent mechanism. The activity of tumor-associated TLS was dictated by the relative balance between functional Tfh TIL and functional Tfr TIL. These data provide mechanistic insight into TLS processes orchestrated by functional Th1-oriented Tfh TIL, including TIL-B and CD8+ TIL activation and immunological memory generation. Tfh TIL, regulated by functional Tfr TIL, are an expected key target of PD-1/PD-L1 blockade.

Pan-cancer analysis of whole genomes

Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale1-3. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter4; identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation5,6; analyses timings and patterns of tumour evolution7; describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity8,9; and evaluates a range of more-specialized features of cancer genomes8,10-18.

TP53 Outperforms Other Androgen Receptor Biomarkers to Predict Abiraterone or Enzalutamide Outcome in Metastatic Castration-Resistant Prostate Cancer

PURPOSE

To infer the prognostic value of simultaneous androgen receptor (AR) and TP53 profiling in liquid biopsies from patients with metastatic castration-resistant prostate cancer (mCRPC) starting a new line of AR signaling inhibitors (ARSi).Experimental Design: Between March 2014 and April 2017, we recruited patients with mCRPC (n = 168) prior to ARSi in a cohort study encompassing 10 European centers. Blood samples were collected for comprehensive profiling of CellSearch-enriched circulating tumor cells (CTC) and circulating tumor DNA (ctDNA). Targeted CTC RNA sequencing (RNA-seq) allowed the detection of eight AR splice variants (ARV). Low-pass whole-genome and targeted gene-body sequencing of AR and TP53 was applied to identify amplifications, loss of heterozygosity, mutations, and structural rearrangements in ctDNA. Clinical or radiologic progression-free survival (PFS) was estimated by Kaplan-Meier analysis, and independent associations were determined using multivariable Cox regression models.

RESULTS

Overall, no single AR perturbation remained associated with adverse prognosis after multivariable analysis. Instead, tumor burden estimates (CTC counts, ctDNA fraction, and visceral metastases) were significantly associated with PFS. TP53 inactivation harbored independent prognostic value [HR 1.88; 95% confidence interval (CI), 1.18-3.00; P = 0.008], and outperformed ARV expression and detection of genomic AR alterations. Using Cox coefficient analysis of clinical parameters and TP53 status, we identified three prognostic groups with differing PFS estimates (median, 14.7 vs. 7.51 vs. 2.62 months; P < 0.0001), which was validated in an independent mCRPC cohort (n = 202) starting first-line ARSi (median, 14.3 vs. 6.39 vs. 2.23 months; P < 0.0001).

CONCLUSIONS

In an all-comer cohort, tumor burden estimates and TP53 outperform any AR perturbation to infer prognosis.See related commentary by Rebello et al., p. 1699.

International consensus guidelines for scoring the histopathological growth patterns of liver metastasis

Background:

Liver metastases present with distinct histopathological growth patterns (HGPs), including the desmoplastic, pushing and replacement HGPs and two rarer HGPs. The HGPs are defined owing to the distinct interface between the cancer cells and the adjacent normal liver parenchyma that is present in each pattern and can be scored from standard haematoxylin-and-eosin-stained (H&E) tissue sections. The current study provides consensus guidelines for scoring these HGPs.

Methods:

Guidelines for defining the HGPs were established by a large international team. To assess the validity of these guidelines, 12 independent observers scored a set of 159 liver metastases and interobserver variability was measured. In an independent cohort of 374 patients with colorectal liver metastases (CRCLM), the impact of HGPs on overall survival after hepatectomy was determined.

Results:

Good-to-excellent correlations (intraclass correlation coefficient >0.5) with the gold standard were obtained for the assessment of the replacement HGP and desmoplastic HGP. Overall survival was significantly superior in the desmoplastic HGP subgroup compared with the replacement or pushing HGP subgroup (P=0.006).

Conclusions:

The current guidelines allow for reproducible determination of liver metastasis HGPs. As HGPs impact overall survival after surgery for CRCLM, they may serve as a novel biomarker for individualised therapies.

Landscape of somatic mutations in 560 breast cancer whole-genome sequences

We analysed whole-genome sequences of 560 breast cancers to advance understanding of the driver mutations conferring clonal advantage and the mutational processes generating somatic mutations. We found that 93 protein-coding cancer genes carried probable driver mutations. Some non-coding regions exhibited high mutation frequencies, but most have distinctive structural features probably causing elevated mutation rates and do not contain driver mutations. Mutational signature analysis was extended to genome rearrangements and revealed twelve base substitution and six rearrangement signatures. Three rearrangement signatures, characterized by tandem duplications or deletions, appear associated with defective homologous-recombination-based DNA repair: one with deficient BRCA1 function, another with deficient BRCA1 or BRCA2 function, the cause of the third is unknown. This analysis of all classes of somatic mutation across exons, introns and intergenic regions highlights the repertoire of cancer genes and mutational processes operating, and progresses towards a comprehensive account of the somatic genetic basis of breast cancer.

Microvessel density and endothelial cell proliferation levels in colorectal liver metastases from patients given neo-adjuvant cytotoxic chemotherapy and bevacizumab

The treatment of patients with colorectal liver metastasis has improved significantly and first line therapy is often combined chemotherapy and bevacizumab, although it is unknown who responds to this regimen. Colorectal liver metastases grow in different histological growth patterns showing differences in angiogenesis. To identify possible response markers, histological markers of angiogenesis were assessed. Patients who underwent resection of colorectal liver metastasis at Rigshospitalet, Copenhagen, Denmark from 2007 to 2011 were included (n = 254) including untreated and patients treated with chemotherapy or chemotherapy plus bevacizumab. The resected liver metastases were characterised with respect to growth pattern, endothelial and tumour cell proliferation as well as microvessel density and tumour regression. Tumour regression grade of liver metastases differed significantly between untreated/chemotherapy treated patients in comparison to chemotherapy plus bevacizumab treated patients (both p < 0.0001). Microvessel density was decreased in liver metastases from patients treated with bevacizumab in comparison to those from untreated/chemotherapy-treated patients (p = 0.006/p = 0.002). Tumour cell proliferation assessed by Ki67 expression correlated to a shorter recurrence free survival in the total patient cohort. In conclusion, liver metastases from patients treated with neo-adjuvant chemotherapy and bevacizumab had significantly lower microvessel densities and tumour regression grades when compared to liver metastases from untreated or chemotherapy treated patients. This may indicate that bevacizumab treatment results in altered vascular biology and tumour viability, with possible tumour reducing effect.

Peritumoral D2-40 Chalkley score independently predicts metastases and survival in patients with cutaneous malignant melanoma

BACKGROUND

Many observational studies investigated the prognostic significance of angiogenesis and lymphangiogenesis in patients with melanoma. However, the obtained results are rather contradictory, probably due to the lack of the consensus methodology.

METHODS

To investigate the prognostic significance of angiogenesis and lymphangiogenesis-related parameters in patients with melanoma, we performed a retrospective investigation following the consensus recommendations for angiogenesis and lymphangiogenesis quantification in solid tumors and reporting recommendations for tumor marker (REMARK) criteria for reporting the results. Blood and lymphatic vessel Chalkley scores, endothelial cell proliferation fractions and microvessel densities were quantified using a double immunostaining for endothelial marker CD34 or lymphendothelial marker D240 and the proliferation marker Ki-67 in 196 patients with melanoma. These parameters were evaluated separately for peritumoral (PT) and intratumoral areas and were correlated with outcome.

RESULTS

In multivariate analysis PT D240 Chalkley score was identified as a strongest predictor for sentinel lymph node metastases, non-sentinel lymph node metastases, distant metastases, disease free survival and overall survival in patients with melanoma.

CONCLUSIONS

If additional studies corroborate our findings, we believe that the inclusion of PT D240 Chalkley counts to the routine pathology examination of melanoma samples would provide additional information for identifying high-risk patients.

Mobile DNA in cancer. Extensive transduction of nonrepetitive DNA mediated by L1 retrotransposition in cancer genomes

Long interspersed nuclear element-1 (L1) retrotransposons are mobile repetitive elements that are abundant in the human genome. L1 elements propagate through RNA intermediates. In the germ line, neighboring, nonrepetitive sequences are occasionally mobilized by the L1 machinery, a process called 3' transduction. Because 3' transductions are potentially mutagenic, we explored the extent to which they occur somatically during tumorigenesis. Studying cancer genomes from 244 patients, we found that tumors from 53% of the patients had somatic retrotranspositions, of which 24% were 3' transductions. Fingerprinting of donor L1s revealed that a handful of source L1 elements in a tumor can spawn from tens to hundreds of 3' transductions, which can themselves seed further retrotranspositions. The activity of individual L1 elements fluctuated during tumor evolution and correlated with L1 promoter hypomethylation. The 3' transductions disseminated genes, exons, and regulatory elements to new locations, most often to heterochromatic regions of the genome.

Squamous cell carcinomas of the skin explore angiogenesis-independent mechanisms of tumour vascularization

Aims. To evaluate the vascularization in basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs) of the skin. Methods. We performed CD31 (i.e., panendothelial marker) and CD105 (i.e., proliferating endothelium marker) immunostaining on samples of 70 SCCs and 70 BCCs of the skin. We evaluated the relative blood vessel area using the Chalkley counting method in each histologic subtype of these tumours. We calculated the degree of proliferation of blood vessel endothelium dividing CD105-Chalkley score by CD31-Chalkley score. Results. We found significantly higher peritumoral and intratumoral blood vessel area in SCC when compared to BCC (both with CD31 and CD105). Chalkley counts differed significantly between groups with different BCC histologic subtypes and SCC with different grade of differentiation. Surprisingly, the degree of proliferation of blood vessel endothelium was higher in BCC when compared to SCC. Conclusions. While SCC exhibited significantly higher intratumoral and peritumoral blood vessel areas compared to BCC, the relatively low rate of proliferating endothelium in this tumour type suggests the existence of endothelial-sprouting-independent mechanisms of vascularization in SCC.

The multifaceted role of the microenvironment in liver metastasis: biology and clinical implications

The liver is host to many metastatic cancers, particularly colorectal cancer, for which the last 2 decades have seen major advances in diagnosis and treatment. The liver is a vital organ, and the extent of its involvement with metastatic disease is a major determinant of survival. Metastatic cells arriving in the liver via the bloodstream encounter the microenvironment of the hepatic sinusoid. The interactions of the tumor cells with hepatic sinusoidal and extrasinusoidal cells (endothelial, Kupffer, stellate, and inflammatory cells) determine their fate. The sinusoidal cells can have a dual role, sometimes fatal to the tumor cells but also facilitatory to their survival and growth. Adhesion molecules participate in these interactions and may affect their outcome. Bone marrow-derived cells and chemokines also play a part in the early battle for survival of the metastases. Once the tumor cells have arrested and survived the initial onslaught, tumors can grow within the liver in 3 distinct patterns, reflecting differing host responses, mechanisms of vascularization, and proteolytic activity. This review aims to present current knowledge of the interactions between the host liver cells and the invading metastases that has implications for the clinical course of the disease and the response to treatment.

Abstract 4072: Molecular characterization of single tumor cells isolated from blood samples using immunomagnetic enrichment and dielectrophoretic cell sorting: A feasibility study

Introduction Molecular characterization of CTC holds considerable promise for the identification and monitoring of therapeutic targets in cancer patients under systemic treatment. Molecular profiling of CTC is however frustrated by white blood cell (WBC) signatures overwhelming those emanating from the CTC minority. In this study, we investigated the feasibility to isolate and molecularly characterize single tumor cells (TC) and small pools of up to 10 pure TC from immunomagnetically enriched blood samples using a semi-automated platform for dielectrophoretic cell sorting (DEPArray, Silicon Biosystems, Bologna, IT). Methods MDA-MB-231 human breast cancer cells were spiked into healthy donor blood at a concentration of 1000 cells/7.5 ml blood. Clinical patient samples were obtained from patients with metastatic breast cancer. Blood samples were subjected to EpCAM based immunomagnetic enrichment using the CellSearch Profile Kit (CellSearch, Veridex, Raritan, NJ, USA). Enriched samples were immunofluorescently stained for EpCAM-PE, CD45-APC and Hoechst and subsequently further purified using a DEPArray cell sorter. Single TC, pools of 5 TC, pools of 10 TC and pools of 20 WBC were recovered into individual reaction tubes. Molecular analyses consisting of whole genome amplification followed by K-ras mutation analysis and RT-qPCR for an in-house selected panel of breast cancer related transcripts were performed. Results Genomic DNA (gDNA) was succesfully amplified and detected in 3/5 (60%) single MDA-MB-231 TC and 4/4 (100%) pools of 5-10 TC and 20 WBC. K-ras mutation analysis revealed the G13D mutation - heterozygously present in the MDA-MB-231 cell line - in all TC samples and in none of two WBC samples, indicating 100% purity of the sorted cell samples. In addition, gDNA was succesfully detected and amplified in 5/9 (55%) single TC and 5/6 (83%) pools of 5-10 TC and 20 WBC from a clinical patient sample. Transcriptional profiles of pools of 5-10 MDA-MB-231 TC samples, were consistently correlated with publicly available gene expression profiles of MDA-MB-231 cells (Spearman R2=0.36±0.03) and inversely correlated with gene expression profiles of MCF-7 cells (Spearman R2=−0.09±0.03), indicating correct classification according to molecular subtypes. In a clinical patient sample, transcriptional profiles of pools of CTC could be correctly distinguished from WBC. Discussion We show the feasibility of an integrated workflow for the molecular characterization of single TC and small pools of up to 10 pure TC isolated from immunomagnetically enriched blood samples using a semi-automated dielectrophoretic cell sorting technique. Further optimization is being undertaken to allow for single cell transcriptional profiling and results will be expanded in clinical patient samples in order to gain insight into in vivo CTC heterogeneity.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4072. doi:1538-7445.AM2012-4072

The histological growth pattern of colorectal cancer liver metastases has prognostic value

Little is known about the biological characteristics that determine the prognosis of colorectal cancer (CRC) liver metastases. In previous work we reported three different histological patterns of the tumour-liver interface of CRC liver metastases, termed the pushing, replacement and desmoplastic growth pattern (GP). The purpose of this study was to confirm differences in angiogenic and hypoxic properties of CRC liver metastases with different GPs in a large data set and to study the value of the GP as a prognostic factor. In 205 patients undergoing a resection of CRC liver metastases, the GP of the metastasis was determined using haematoxylin-eosin and Gordon Sweet's silver staining. The tumour cell proliferation fraction (TCP%), endothelial cell proliferation fraction (ECP%) and carbonic anhydrase 9 (CA9) expression were determined using immunohistochemistry. Standard clinicopathological data and overall survival were recorded. 27.8, 15.6, 34.6 and 17.6 % of liver metastases had a replacement, pushing, desmoplastic and mixed GP, respectively. Analyses of TCP%, ECP% and CA9 expression demonstrated that CRC liver metastases with a replacement GP are non-angiogenic, while the ones with a pushing GP are the most angiogenic with angiogenesis being, at least partially, hypoxia-driven. GP (pushing or not) was the only independent predictor of survival at 2 years. CRC liver metastases grow according to different GP patterns with different angiogenic properties. At 2 years of follow-up a GP with a pushing component was an independent predictor of poor survival, suggesting that the pushing GP is characterized by a more aggressive tumour biology. Further elucidation of the mechanisms and biological pathways involved in and responsible for the differences in GP between CRC liver metastases in different patients might lead to therapeutic agents and strategies taking advantage of this 2 year 'window of opportunity'.

Growth patterns of liver metastases as compared to resected tumors of the same colorectal cancer patients

519

Background: Colorectal cancer (CRC) affects one million people a year. 25% of the patients have metastatic disease at the time of diagnosis. Metastatic disease is one of the major challenges in the treatment of cancer. Even though the TNM staging system is a good prognostic marker, tumours have a biological diversity that cannot be evaluated by the TNM system. Recently three different growth patterns of CRC liver metastases were identified. The aim of this study was to determine the growth patterns of CRC liver metastases from patients with more than one metastasis.

Methods: A pilot study was conducted including 34 patients resected for CRC liver metastases, 28 patients selected from a database of 200 patients, operated in Copenhagen between 2007-2010 and 6 patients, operated in Montreal. From these 34 patients, 15 patients were resected for two or more liver metastases. All paraffin embedded tissue sections were stained for reticulin and haematoxylin and eosin at the Finsen Laboratory. Evaluation of the growth pattern was done by three different observers from Antwerp and Copenhagen. Reproducibility was >90%.

Results: In the fifteen patients, 9 from Copenhagen and 6 from Montreal, that had multiple hepatic metastases, there was uniformity in the growth pattern of the individual metastases. 40% had a desmoplastic, 33% a pushing and 20% a replacement growth pattern and 7% had a mix pattern. Of the 9 patients from Copenhagen 33% were synchronous and 67% metachronous metastases. Within patients, all patterns were identical.

Conclusions: The uniformity of growth patterns seen in each patient suggests that these patterns are not random. The identical growth pattern may be determined by specific interactions between the tumor and the host microenvironment, as postulated by Paget’s seed and soil theory. This could represent three different stromal and cytokine responses or oncogenic pathway responses and could represent metastatic tumour growth in different microenvironments.

Abstract 5243: Gene expression analysis of CRC liver metastases with different growth patterns

Introduction: Liver metastases of colorectal cancer (CRC) grow according to different growth patterns (GPs) with different angiogenic properties. The aim of this study was to characterize these GPs on a molecular level using genome-wide gene expression analysis.

Materials and Methods: On 18 CRC liver metastases of which genome-wide gene expression data were available from a previous study (publicly available at GSE 10961), we assessed the GP using a haematoxylin-eosin and Gordon Sweet's reticulin stain. 7 metastases had a desmoplastic GP, 6 had a pushing GP and 3 had a replacement GP. Of 2 metastases the GP could not be assessed due to lack of sufficient material and these were excluded for further analysis. We used (hierarchical) cluster analysis, principal component analysis, significance/prediction analysis of microarrays and gene set enrichment analysis to study differences in gene expression between the different GPs.

Results: Principal component analysis and hierarchical cluster analysis showed significant gene expression differences between metastases with a desmoplastic and pushing GP (p=2.2e−16) and between metastases with a desmoplastic and replacement GP (p=2.2e−16). Gene set enrichment analysis demonstrated increased expression of biological processes, molecular functions, cellular components and KEGG pathways related to immune response, antigen processing, leucocyte activation and cell adhesion molecules in the metastases with a desmoplastic GP. Similar differences were found when metastases with a pushing GP were compared to metastases with a replacement GP and when the 3 groups were compared.

Conclusion: These results confirm on a molecular level that liver metastases of patients with CRC have a heterogeneous biology. Metastases with a desmoplastic GP appear to have upregulation of immunological processes, compared to metastases with a pushing or replacement GP. Further elucidation of these differences might lead to better understanding of host-tumour interactions in metastatic biology and new therapeutic strategies for patients with metastatic CRC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5243. doi:10.1158/1538-7445.AM2011-5243

Different angiogenic potential in low and high grade sporadic clear cell renal cell carcinoma is not related to alterations in the von Hippel-Lindau gene

BACKGROUND

von Hippel-Lindau (VHL) inactivation is common in sporadic clear cell renal cell carcinomas (ccRCC). pVHL is part of the ubiquitin ligase complex that targets the alpha subunits of hypoxia-inducible transcription factor (HIF) for degradation under well-oxygenated conditions. In the absence of wild-type pVHL, as observed in VHL patients and most sporadic ccRCCs, constitutive upregulation of HIF results in transcriptional activation of angiogenesis-related genes, such as VEGF. Differences in angiogenic activity within the group of ccRCCs were reported and strong genotype-phenotype correlations were found in patients with VHL disease, raising a question about the importance of VHL inactivation status in angiogenic behaviour and tumour progression.

METHODS

To address this question, we investigated the influence of VHL mutation (direct sequencing)/hypermethylation (methylation-specific PCR) on angiogenesis/tumour parameters (immunohistochemistry) in 150 patients with sporadic ccRCC.

RESULTS

We found no significant association between VHL mutation or methylation and angiogenesis/tumour parameters.

CONCLUSION

These data indicate that tumour progression and angiogenesis are not directly influenced by VHL alterations and that additional genetic/epigenetic events should be considered to explain the diverse angiogenic and proliferative behaviour during tumour progression.

Propofol infusion syndrome with arrhythmia, myocardial fat accumulation and cardiac failure

Propofol is a potent and widely used central-acting sedative drug. It has been implicated in the development of a usually fatal syndrome characterized by metabolic acidosis, rhabdomyolysis, ventricular arrhythmia, and Brugada-like cardiac rhythm disturbances, all leading to cardiac and renal failure. The investigators describe a 12-year-old male patient with a fatal case of this so-called propofol infusion syndrome. Postmortem investigation showed not only the well-known myocytolysis in skeletal and cardiac muscle but also not previously demonstrated widespread fat accumulation in the myocardium. In conclusion, this cardiac fat accumulation illustrates the proposed underlying pathophysiology of impaired (muscular) free fatty acid utilization.

Gene expression profiles associated with the presence of a fibrotic focus and the growth pattern in lymph node-negative breast cancer

PURPOSE

A fibrotic focus, the scar-like area found in the center of an invasive breast tumor, is a prognostic parameter associated with an expansive growth pattern, hypoxia, and (lymph)angiogenesis. Little is known about the molecular pathways involved.

EXPERIMENTAL DESIGN

Sixty-five patients were selected of whom microarray data of the tumor and H&E slides for histologic analysis were available. The growth pattern and the presence and size of a fibrotic focus were assessed. Differences in biological pathways were identified with global testing. The correlations of growth pattern and fibrotic focus with common breast cancer signatures and with clinicopathologic variables and survival were investigated.

RESULTS

Tumors with a large fibrotic focus showed activation of Ras signaling and of the hypoxia-inducible factor-1alpha pathway. Furthermore, unsupervised hierarchical cluster analysis with hypoxia- and (lymph)angiogenesis-related genes showed that hypoxia-inducible factor-1alpha, vascular endothelial growth factor A, and carbonic anhydrase 9 were overexpressed. The presence of a fibrotic focus, especially a large fibrotic focus, was associated with the basal-like subtype (P = 0.009), an activated wound-healing signature (P = 0.06), and a poor-prognosis 76-gene signature (P = 0.004). The presence of a fibrotic focus (P = 0.02) and especially of a large fibrotic focus (P = 0.004) was also associated with early development of distant metastasis.

CONCLUSIONS

Our results sustain the hypothesis that hypoxia-driven angiogenesis is essential in the biology of a fibrotic focus. Ras and Akt might play a role as downstream modulators. Our data furthermore suggest that vascular endothelial growth factor A does not only drive angiogenesis but also lymphangiogenesis in tumors with a fibrotic focus. Our data also show an association between the presence of a fibrotic focus and infaust molecular signatures.

Nuclear factor-kappaB signature of inflammatory breast cancer by cDNA microarray validated by quantitative real-time reverse transcription-PCR, immunohistochemistry, and nuclear factor-kappaB DNA-binding

PURPOSE

Inflammatory breast cancer (IBC) is the most aggressive form of locally advanced breast cancer with high metastatic potential. In a previous study, we showed that IBC is a different form of breast cancer compared with non-IBC by cDNA microarray analysis. A list of 756 genes with significant expression differences between IBC and non-IBC was identified. In-depth functional analysis revealed the presence of a high number of nuclear factor-kappaB (NF-kappaB) target genes with elevated expression in IBC versus non-IBC. This led to the hypothesis that NF-kappaB contributes to the phenotype of IBC. The aim of the present study was to further investigate the role of NF-kappaB in IBC.

EXPERIMENTAL DESIGN

Immunohistochemistry and NF-kappaB DNA-binding experiments were done for all NF-kappaB subunits (RelA, RelB, cRel, NFkB1, and NFkB2) using IBC and non-IBC specimens. Transcriptionally active NF-kappaB dimers were identified by means of coexpression analysis. In addition, quantitative real-time reverse transcription-PCR for eight NF-kappaB target genes, selected upon a significant, 3-fold gene expression difference between IBC and non-IBC by cDNA microarray analysis, was done.

RESULTS

We found a significant overexpression for all of eight selected NF-kappaB target genes in IBC compared with non-IBC by quantitative real-time reverse transcription-PCR. In addition, we found a statistically elevated number of immunostained nuclei in IBC compared with non-IBC for RelB (P = 0.038) and NFkB1 (P < 0.001). Immunohistochemical data were further validated by NF-kappaB DNA-binding experiments. Significant correlations between immunohistochemical data and NF-kappaB DNA binding for RelA, RelB, NFkB1, and NFkB2 were found. Transcriptionally active NF-kappaB dimers, composed of specific combinations of NF-kappaB family members, were found in 19 of 44 IBC specimens compared with 2 of 45 non-IBC specimens (P < 0.001). In addition, we found evidence for an estrogen receptor (ER)-mediated inhibition of the NF-kappaB signaling pathway. NF-kappaB target genes were significantly elevated in ER- versus ER+ breast tumors. Also, the amount of immunostained nuclei for RelB (P = 0.025) and NFkB1 (P = 0.031) was higher in ER- breast tumors versus ER+ breast tumors.

CONCLUSIONS

The NF-kappaB transcription factor pathway probably contributes to the phenotype of IBC and possibly offers new options for treatment of patients diagnosed with this aggressive form of breast cancer.

Increased Sentinel Lymph Node Lymphangiogenesis is Associated with Nonsentinel Axillary Lymph Node Involvement in Breast Cancer Patients with a Positive Sentinel Node

PURPOSE

Lymph node (LN) lymphangiogenesis has recently been shown to be important in the premetastatic niche of sentinel LNs. To study its role in the further metastatic spread of human breast cancer, we investigated the association of angiogenesis and lymphangiogenesis in sentinel LN metastases with the presence of nonsentinel LN metastases in breast cancer patients with a positive sentinel LN.

EXPERIMENTAL DESIGN

Angiogenesis and lymphangiogenesis--quantified as endothelial cell proliferation fraction (ECP%) and lymphatic ECP fraction (LECP%)--were assessed in sentinel LN metastases of 65 T(1)/T(2) patients with breast cancer using CD34/Ki67 and D2-40/Ki67 immunohistochemical double stains. Correlations were analyzed between nonsentinel LN status, LECP%, and other clinicopathologic variables (number of involved sentinel LNs, size of the primary tumor and LN metastasis, presence of lymphovascular invasion in the primary tumor, and of extracapsular growth in the sentinel LN metastasis).

RESULTS

Thirty seven out of 65 patients (56.9%) had at least one involved nonsentinel LN. Size of the sentinel LN metastasis (P = 0.001), lymphovascular invasion (P = 0.02), extracapsular growth (P = 0.02), and LECP% (P = 0.01) were correlated with a positive nonsentinel LN status. The multivariate logistic regression model retained high LECP% (odds ratios = 4.2, P = 0.01) and the presence of extracapsular growth (odds ratios = 3.38, P = 0.04) as independently associated with the presence of nonsentinel LN metastases.

CONCLUSIONS

Increased sentinel LN metastasis lymphangiogenesis is associated with metastatic involvement of nonsentinel axillary LNs. These are the first data sustaining the hypothesis that sentinel LN lymphangiogenesis is involved in further metastatic spread of human breast cancer.

PTHrP, calcitonin and calcitriol in a case of severe, protracted and refractory hypercalcemia due to a pancreatic neuroendocrine tumor

A patient with a primary neuroendocrine tumor of the pancreas, presented with severe hypercalcemia. This hypercalcemia of malignancy (HCM) failed to respond to intensive bisphosphonate treatment and needed continuous enhanced diuresis. Only after successful antitumor therapy did the hypercalcemia subside. Hypercalcemia was associated with increased concentrations of plasma PTHrP, calcitonin and 1,25-(OH)(2)D(3). Bone mineral density was markedly increased. We demonstrated the presence of both PTHrP and calcitonin in the tumor at the mRNA and protein level, using RT-PCR, immunohistochemistry and Western blotting. The high levels of plasma PTHrP and the demonstrated predominant renal mechanism in this case of HCM are suspected to be the cause for its refractoriness to bone resorption inhibitors. Our findings furthermore suggest that the tumoral production of calcitonin and PTHrP might have contributed to the increased bone mineral storage of calcium and thus probably attenuated the development of frank hypercalcemia.

Differential expression of hypoxia and (lymph)angiogenesis-related genes at different metastatic sites in breast cancer

INTRODUCTION

Breast cancer can metastasize via lymphatic and hematogenous pathways. Hypoxia and (lymph)angiogenesis are closely related processes that play a pivotal role in the tumor progression and metastasis. The aim of this study was to compare expression of hypoxia and (lymph)angiogenesis-related genes between primary breast tumors and metastases in different tissues.

MATERIALS AND METHODS

A gene list of 269 hypoxia and (lymph)angiogenesis-related genes was composed and validated using Onto-Express, Pathway-express and Ingenuity software. The expression of these genes was compared in microarray data of 62 samples of primary tumors and metastases of 31 patients with breast cancer retrieved from Gene Expression Omnibus. Similarity between samples was investigated using unsupervised hierarchical clustering analysis, principal component analysis and permutation testing. Differential gene expression between primary tumors and metastases and between metastases from different organs was analyzed using Kruskall-Wallis and Mann-Whitney statistics.

RESULTS

Unsupervised hierarchical cluster analysis demonstrated that hypoxia and (lymph)angiogenesis-related gene expression was more similar between samples from the same patient, than between samples from the same organ. Principal component analysis indicated that 22.7% and 7.0% of the total variation in the gene list was respectively patient and organ related. When differences in gene expression were studied between different organs, liver metastases seemed to differ most from the other secondary sites. Some of the best characterized molecules differentially expressed were VEGFA, PDGFRB, FGF4, TIMP1, TGFB-R1 and collagen 18A1 (precursor of endostatin). To confirm the results of these experiments at the protein level, immunohistochemical experiments were performed with antibodies for VEGFA and MMP-2.

CONCLUSIONS

Our results suggest that hypoxia and (lymph)angiogenesis-related gene expression is more dependent on the characteristics of the primary tumor than on the characteristics of the organs that bear the metastasis. However, when different organs are compared, the expression in liver metastases differs most from other metastatic sites and primary tumors, possibly due to organ-specific angiogenic and lymphangiogenic responses to metastasis-related hypoxia.

Tumor lymphangiogenesis in inflammatory breast carcinoma: a histomorphometric study

PURPOSE

At the time of diagnosis, metastatic dissemination of tumor cells via the lymphatic system has occurred in nearly all patients with inflammatory breast cancer (IBC). The objective of this study was twofold: (a) to determine which is the most suitable marker of lymph vessels in primary breast tumors and (b) to compare histomorphometric lymph vessel variables in IBC and non-IBC.

EXPERIMENTAL DESIGN

Serial sections of 10 IBCs and 10 non-IBCs were immunostained for D2-40, LYVE-1, podoplanin, and PROX-1. Relative lymph vessel area, lymph vessel perimeters, and counts and lymphatic endothelial cell proliferation (LECP) were then measured in D2-40/Ki-67 double-immunostained sections of 10 normal breast tissues, 29 IBCs, and 56 non-IBCs.

RESULTS

D2-40 was the most suitable antibody for staining peritumoral and intratumoral lymph vessels. D2-40-stained intratumoral lymph vessels were present in 80% of non-IBCs and 82.8% of IBCs (P = 0.76). In non-IBC, lymph vessels located in the tumor parenchyma were smaller and less numerous than those at the tumor periphery (P < 0.0001) whereas in IBC, intratumoral and peritumoral variables were not significantly different. The mean relative tumor area occupied by lymph vessels was larger in IBC than in non-IBC (P = 0.01). LECP at the tumor periphery was higher in IBC than in non-IBC: median LECP was 5.74% in IBC versus 1.83% in non-IBC (P = 0.005).

CONCLUSIONS

The high LECP in IBC suggests that lymphangiogenesis contributes to the extensive lymphatic spread of IBC.

Identification of cell-of-origin breast tumor subtypes in inflammatory breast cancer by gene expression profiling

Inflammatory breast cancer (IBC) is an aggressive form of locally advanced breast cancer with high metastatic potential. Most patients have lymph node involvement at the time of diagnosis and 1/3 of the patients have distant metastases. In a previous study, we demonstrated that IBC is a distinct form of breast cancer in comparison with non-IBC. The aim of this study was to investigate the presence of the different molecular subtypes in our data set of 16 IBC and 18 non-IBC specimen. Therefore, we selected an 'intrinsic gene set' of 144 genes, present on our cDNA chips and common to the 'intrinsic gene set' described by Sorlie et al. [PNAS, 2003]. This set of genes was tested for performance in the Norway/Stanford data set by unsupervised hierarchical clustering. Expression centroids were then calculated for the core members of each of the five subclasses in the Norway/Stanford data set and used to classify our own specimens by calculating Spearman correlations between each sample and each centroid. We identified the same cell-of-origin subtypes in IBC as those already described in non-IBC. The classification was in good agreement with immunohistochemical data for estrogen receptor protein expression and cytokeratin 5/6 protein expression. Confirmation was done by an alternative unsupervised hierarchical clustering method. The robustness of this classification was assessed by an unsupervised hierarchical clustering with an alternative gene set of 141 genes related to the cell-of-origin subtypes, selected using a discriminating score and iterative random permutation testing. The contribution of the different cell-of-origin subtypes to the IBC phenotype was investigated by principal component analysis. Generally, the combined ErbB2-overexpressing and basal-like cluster was more expressed in IBC compared to non-IBC, whereas the combined luminal A, luminal B and normal-like cluster was more pronounced in non-IBC compared to IBC. The presence of the same molecular cell-of-origin subtypes in IBC as in non-IBC does not exclude the specific molecular nature of IBC, since gene lists that characterize IBC and non-IBC are entirely different from gene lists that define the different cell-of-origin subtypes, as evidenced by principal component analysis.

Overexpression of caveolin-1 and -2 in cell lines and in human samples of inflammatory breast cancer

PURPOSE

Inflammatory breast cancer (IBC) is the most aggressive form of locally advanced breast cancer (LABC). The IBC phenotype is characterized by an infiltrative growth pattern, increased (lymph)angiogenesis and the propensity to invade dermal lymphatics. In pancreatic cancer, interactions between caveolin-1 and RhoC GTPase, a key molecule in causing the IBC phenotype, regulate tumour cell motility and invasion. In this study we sought to investigate the role of caveolin-1 and -2 in IBC cell lines and in human IBC samples.

EXPERIMENTAL DESIGN

Differential methylation techniques identified the methylation status of the caveolin-1 and -2 promoters in human mammary epithelial cells (HMECs) and the SUM149 cell line. In cell line experiments, caveolin-1 and -2 mRNA and protein expression were compared in HMECs, MCF10A, the SUM102 non-IBC cell lines and 2 IBC cell lines (SUM149 and SUM190). Furthermore, caveolin-1 and -2 mRNA and protein expression were compared in human IBC and non-IBC samples using cDNA microarray, real-time qRT-PCR and immunohistochemistry. Results were correlated with RhoC protein expression data.

RESULTS

In the SUM149 cell line, the caveolin-1 and -2 promoter sites were hypomethylated. A significantly increased expression of caveolin-1 and -2, both at the mRNA and protein level was found in IBC cell lines and in human samples of IBC: caveolin-1 and -2 mRNA were respectively 1.7 (p = 0.02) and 2.2 (p = 0.03) fold more expressed in IBC compared to non IBC and at the protein level, 41.4% of IBC specimens expressed either caveolin-1 or -2, compared to 15.6% of non-IBC specimens (p = 0.03). Furthermore a correlation was found between RhoC protein expression and caveolin-1 (p = 0.1) or caveolin-2 (p = 0.09) or either caveolin-1 or -2 protein expression (p = 0.04).

CONCLUSIONS

Although considered a tumour suppressor in breast cancer, we demonstrated overexpression of caveolin-1 and -2 in IBC cell lines and in human samples of IBC, most likely due to hypomethylation of their respective promoters. These results confirm the distinct molecular signature of IBC. Our data further suggest interaction between RhoC GTPase and the caveolins in IBC.

Distinct Molecular Signature of Inflammatory Breast Cancer by cDNA Microarray Analysis

Inflammatory breast cancer (IBC) is a clinically distinct and aggressive form of locally advanced breast cancer with largely unknown genetic determinants. Overexpression of the RhoC GTPase and of HER2, and decreased ER-expression are involved in IBC. Multimodality treatment has increased survival but prognosis is still poor. Novel molecular targets for improved neoadjuvant treatment are necessary. Using cDNA microarrays, we performed genome-wide expression profiling of pre-treatment tumour samples of 16 patients with IBC and 18 patients with non-stage-matched non-IBC. Rigid clinical diagnostic criteria according to the TNM classification of the American Joint Committee on Cancer were adopted. Unsupervised hierarchical clustering accurately distinguished IBC and non-IBC samples. A set of 50 discriminator genes was identified in a learning group of tumour samples and was successful in diagnosing IBC in a validation group of samples (accuracy of 88%). Exclusion of ER-related or HER2-related genes did not alter this discriminatory accuracy, indicating that the expression of other genes in addition to ER and HER2 characterize the IBC phenotype. The molecular signature of IBC revealed the overexpression of a large number of NF-kappaB target genes, explaining at least part of the aggressive nature of IBC. Successful validation of some of the overexpressed genes by immunohistochemistry or real-time quantitative PCR demonstrated the robustness of the cDNA microarray experiments. The results of our study provide potential targets for the treatment of patients with IBC.

Increased angiogenesis and lymphangiogenesis in inflammatory versus noninflammatory breast cancer by real-time reverse transcriptase-PCR gene expression quantification

PURPOSE

Inflammatory breast cancer is a distinct and aggressive form of locally advanced breast cancer with unique clinical and pathological features. Recently, histologic evidence of intense angiogenesis was found in inflammatory breast cancer specimens. The aim of this study was to confirm the angiogenic phenotype of inflammatory breast cancer and to investigate its potential to induce lymphangiogenesis.

EXPERIMENTAL DESIGN

Real-time quantitative reverse transcriptase-PCR was used to measure levels of mRNA of tumor angiogenesis and lymphangiogenesis-related factors [vascular endothelial growth factor (VEGF)-A, VEGF-C, VEGF-D, Flt-1, KDR, Flt-4, Ang-1, Ang-2, Tie-1, Tie-2, cyclooxygenase-2, fibroblast growth factor-2 (FGF-2), Egr-1, Prox-1, and LYVE-1] in tumor specimens of 16 inflammatory breast cancer and 20 noninflammatory breast cancer patients. Tissue microarray technology and immunohistochemistry were used to study differential protein expression of some of the angiogenic factors in inflammatory breast cancer and noninflammatory breast cancer. Active lymphangiogenesis was further assessed by measuring lymphatic endothelial cell proliferation.

RESULTS

Inflammatory breast cancer specimens had significantly higher mRNA expression levels than noninflammatory breast cancer specimens of the following genes: KDR (P = 0.033), Ang-1, (P = 0.0001), Tie-1 (P = 0.001), Tie-2 (P = 0.001), FGF-2 (P = 0.002), VEGF-C (P = 0.001), VEGF-D (P = 0.012), Flt-4 (P = 0.001), Prox-1 (P = 0.005), and LYVE-1 (P = 0.013). High mRNA levels of FGF-2 and cyclooxygenase-2 corresponded to increased protein expression by immunohistochemistry. Inflammatory breast cancer specimens contained significantly higher fractions of proliferating lymphatic endothelial cells than noninflammatory breast cancer specimens (P = 0.033).

CONCLUSIONS

Using real-time quantitative reverse transcriptase-PCR and immunohistochemistry, we confirmed the intense angiogenic activity in inflammatory breast cancer and demonstrated the presence of active lymphangiogenesis in inflammatory breast cancer. This may help explain the high metastatic potential of inflammatory breast cancer by lymphatic and hematogenous route. Both pathways are potential targets for the treatment of inflammatory breast cancer.