2008 Summer Meeting - Leeds - The Pathological Society of Great ...

O5An Altered Myoepithelial Cell Phenotype in DCIS InfluencesTumour-Associated AngiogenesisSJL Payne 1 ,MAllen 1 ,IHart 1 , JL Jones 11 Queen Mary University LondonThe process of angiogenesis is a critical factor in breast tumour progression andhas also been demonstrated in preneoplastic breast lesions.Limited published data suggests that myoepithelial cells are anti-angiogenic.This observation is based on ‘normal’ myoepithelial cells. It is recognised,however, that myoepithelial cells are altered in DCIS. We have previouslydemonstrated a difference characterised by the up-regulation v6. This studyaimed to investigate whether expression of v6 in DCIS is associated withangiogenesis, and to establish if v6 expression could contribute to enhancedangiogenesis.Immunohistochemistry for v6 and the vascular marker CD31 was carried outon tissue microarrays (TMAs) of 148 cases of pure DCIS, and on wholesections from 36 of these cases. TMAs were found to be of limited use inanalysis. In whole sections, 47% expressed v6 with 53% negative for v6.The angiogenic pattern was scored as rim pattern, where vessels are adjacent tothe DCIS ducts and diffuse pattern, where vessels are present in the surroundingstroma. A rim pattern of staining was only seen in the v6 positive group.Using an immortalised myoepithelial cell line (1089) and an v6 overexpressingcounterpart (6-1089), we demonstrated that 6-1089 cells releasehigher levels of VEGF than 1089 cells and also stimulated more vascularsprouting in a mouse aortic ring assay. This supports the hypothesis that upregulationof v6 on myoepithelial cells in DCIS is of functional significanceand may contribute to invasive progression.O7Neural networks identify gene profiles that predict clinicaloutcome with high accuracy in breast cancer: CA IX isidentified as the principal prognostic indicatorLJ Lancashire 1 , DG Powe 2 ,ERakha 2 , AR Green 2 ,RMukta 2 ,EC Paish 2 , RC Rees 3 , IO Ellis 2 , GR Ball 31 Clinical and Experimental Pharmacology, Paterson Institute for CancerResearch, 2 Department of Histopathology, Nottingham UniversityHospitals Trust and University of Nottingham, 3 The Nottingham TrentUniversity, School of Science and TechnologyGene expression microarrays allow for the high throughput analysis ofhundreds of thousands of gene transcripts. This technology has been applied tothe molecular classification of cancer patients. Subsequently, it is recognisedthat different patient subgroups show distinct molecular signaturescorresponding to cancer-associated disease pathways. Importantly, these geneprofiles provide information on clinical outcome. A potential handicap of suchhigh throughput technologies is the unprecedented amount of data generated,often of high complexity. This has created a demand for novel data analysismethodologies. Here, we present an Artificial Neural Network basedmethodology that has identified a prognostic gene expression signature in breastcancer. In applying this approach to a previously published seminal data set wehave identified nine key genes whose expression profiles are capable ofpredicting development of distant metastases to accuracies of 98%. Theprincipal prognostic indicator identified was carbonic anhydrase IX (CA IX), acomponent of the hypoxia-pathway. We subsequently tested the suitability ofCA IX for predicting survival outcome using semi-quantitativeimmunohistochemical morphometry on a large number of unselected breastcancers. Interestingly, our results showed that membranous CA IX expression ispredictive of shortened overall survival, reduced disease free interval, andlymph node involvement.O6Genomic and Immunophenotypical Characterisation of PureMicropapillary Carcinomas of the BreastCMarchio 1 ,MIravani 1 , R Natrajan 1 , MB Lambros 1 , K Savage 1 ,S Di Palma 2 , FC Schmitt 3 , G Bussolati 4 , IO Ellis 5 , A Ashworth 1 ,ASapino 4 , JS Reis-Filho 1 .1 The Breakthrough Breast Cancer Research Centre – Institute of CancerResearch, London, 2 RSCH, Guildford, 3 IPATIMUP, Porto, Portugal4 Department of Biomedical Sciences and Human Oncology, University ofTurin, Torino, Italy, 5 Department of Histopathology, Nottingham CityHospital NHS Trust and University of Nottingham, NottinghamPure invasive micropapillary carcinoma (MPC) is a special type of breastcancer characterised by a distinctive growth pattern and a more aggressiveclinical behaviour than invasive ductal carcinomas of no special type (IDC-NSTs). To define the molecular characteristics of MPCs, we profiled 12 MPCsand 24 grade and oestrogen receptor (ER)-matched IDC-NSTs using microarraycomparative genomic hybridisation (aCGH). In addition, we generated a tissuemicroarray containing a series of 24 MPCs and performedimmunohistochemistical analysis with ER, PR, Ki67, HER2, CK5/6, CK14,CK17, EGFR, topoisomerase-II, cyclin D1, caveolin-1, E-cadherin and -catenin antibodies. In situ hybridisation probes were employed to evaluate theprevalence of amplification of HER2, TOP2A, EGFR, CCND1, MYC, ESR1and FGFR1 genes. aCGH analysis demonstrated that MPCs significantlydiffered from IDC-NSTs at the genomic level. Gains of 1q, 2q, 4p, 6p, 6q23,7p, 7q, 8p, 8q, 9p, 10p, 11q, 12p, 12q, 16p, 17p, 17q, 19p, 20p, 20q and 21qand losses of 1p, 2p, 6q11, 6q21, 9p, 11p, 15q and 19q were more prevalent inMPCs. Amplifications of 8p12, 8q12, 8q13, 8q21, 8q23, 8q24, 17q21, 17q23and 20q13 were significantly associated with MPCs. A comparison between 24MPCs and a series of 48 grade and ER matched IDC-NSTs revealed that highcyclin D1 expression, high proliferation rates and MYC amplification weresignificantly associated with MPCs. Our results demonstrate that MPCs havedistinctive histological features and molecular genetic profiles supporting thecontention that they constitute a distinct pathological entity.O8Clear Cells of the Nipple Epidermis: a Reserve of MotileMammary Precursor Cells?JGoing 1 ,MCurrie 11 University of GlasgowBackground: Clear cells of the nipple epidermis [Toker, Cancer 1970] have noknown function but, with a relationship to mammary duct ostia andultrastructural features in common with light cells of the mammary epithelium,it has been proposed that they migrate into nipple epidermis from subjacentducts [Marucci, Virchows Archiv 2002].Aims and methods: We examined clear cell morphology and relationships inthe nipple in 30 mastectomy breasts. Paraffin sections were immunostained forcytokeratins 7+8, 14 and progesterone receptor (PR).Results: Ck 7/8 and PR positive clear cells clustered around duct ostia wereabundant in 6, fairly numerous in 7, scanty in 10 and absent in 7 cases. Theymay be single, clumped or form hollow spheroids. Some have a 'foot' onbasement membrane. A subset show structural features implying motility. Athin protrusion inserted with the aid of a leading filopodium (microspike)between adjacent keratinocytes is anchored by a rounded, club-like termination.The protrusion thickens, most strikingly at its far end, and adopts a flattened,lamellipodium-like contact profile with adjacent keratinocytes beforeshortening to draw the cell body in the direction of travel.Conclusions: Clear cells of the nipple epidermis are associated with ductopenings and combine a lack of differentiated features with apparent motility.We propose that they represent a reserve of mammary progenitor cells, and thattrafficking of precursor cells between separate mammary lobes via the nippleepidermis is a possible mode of mammary gland maintenance over repeatedcycles of pregnancy and lactation.Summer Meeting (194 th ) 1–4 July 2008 Scientific Programme79