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

P29Biological Characteristics of ER Positive Operable BreastCancer in Elderly Patients Treated with Primary EndocrineTherapyOGaniyat 1,2 , AR Green 1 ,MYing 2 , EC Paish 1 , IO Ellis 1 ,KL Cheung 2 .1 Division of Pathology, School of Molecular Medical Sciences,Nottingham University Hospitals and University of Nottingham,Nottingham, 2 Division of Breast Surgery, Nottingham University Hospitalsand University of Nottingham, NottinghamPrimary endocrine therapy (PET) with tamoxifen has been used in the elderlywith oestrogen receptor positive (ER+) primary breast cancer (PBC) who refuseor are unfit for surgery. However little is known about their biologicalcharacteristics, which may be important in therapeutic strategies such asselecting endocrine agents as primary, neoadjuvant or adjuvant therapy.We therefore analysed a cohort of 133 patients aged 70 years with ER+positive early operable PBC receiving endocrine therapy and assessed forresponse to treatment (UICC criteria). Median duration of follow-up was 17months (range=1-150) and. Core biopsies were analysed for expression of PgR,ER2, HER2, EGFR and Ki-67, using immunohistochemistry, to determine ifany of biological tumour characteristics could predict treatment efficacy.The biological characteristics of the tumours were:PgR ER2 HER2 EGFR Ki-67+ - + - + - + - + -71 61 132 1 10 123 6 127 49 84There was no association between PgR, ER2, EGFR expression and responseto treatment, time to progression or duration of response (DoR) However, therewas a significantly shorter DoR with HER-2 positive tumours (p=0.003) andthose with higher growth fraction (p=0.042).Expression of HER2 and growth fraction could therefore potentially bemarkers of a shorter duration of response to endocrine therapy in elderlypatients. Clinical follow-up for longer-term efficacy assessment is continuing inorder to further elucidate the relationship between endocrine sensitivity andthese biological characteristics.P31Tiling Path Array CGH Analysis of HER2 Amplified Cancers:The Influence of ER StatusR Natrajan 1 , C Marchio 1 , MBK Lambros 1 , D Hungermann 2 ,KK Shiu 1 ,DSP Tan 1 , B Mahler-Araujo 1 , A Mackay 1 ,NTamber 1 ,K Fenwick 1 , J Palacios 3 , H Buerger 4 , A Ashworth 1 ,JS Reis-Filho 1 .1 The Breakthrough Breast Cancer Research Centre, Institute of CancerResearch, London, 2 Institute of Pathology, University of Muenster,Muenster, Germany, 3 Hospital Universitario Virgen del Rocío, Seville,Spain, 4 Institute of Pathology, Paderborn, GermanyThe molecular genetic profiles of breast cancers have been shown to be stronglycorrelated with histological grade and oestrogen receptor (ER) expression.Expression profiling analysis has demonstrated that HER2 amplified breastcarcinomas fall into two distinct molecular subgroups: those that express ER,usually cluster together with luminal B cancers, whereas HER2 amplified/ ERnegativecancers form a distinct group. We hypothesised that thesetranscriptomic differences could be driven by distinct patterns of genomicchanges in ER positive vs ER negative HER2 amplified tumours. To test thishypothesis, we profiled 26 HER2 amplified cancers, of which 11 were ERpositive,with tiling path microarray based comparative genomic hybridisationanalysis. Surprisingly, supervised categorical analysis revealed that 1.42% ofthe genome was significantly differentially gained, lost or amplified in thesetwo subgroups of HER2 amplified carcinomas. Two regions were significantlymore frequently amplified in ER positive HER2 amplified tumours: 11q13.3(69.18-69.31Mb) and 17q21 (35.72-35.89Mb). Using probes specific to theseregions, chromogenic in situ hybridisation analysis confirmed the presence ofamplifications at these two loci. No amplification of ESR1 gene was found inER positive cancers. HER2 amplified breast carcinomas constitute a distinct yetheterogeneous group of tumours at the genetic level, however the differences inthe genetic profiles do not seem to be driven by the ER status of the tumours.P30SLC12A2 is an Oestrogen-regulated Gene that is Expressed inBreast CancerPK Wright 1,2 , FEB May 1 ,SDarby 1 , TWJ Lennard 2 ,BR Westley 1 .1 Northern Institute for Cancer Research, Medical School, NewcastleUniversity, Newcastle upon Tyne, 2 School of Surgical and ReproductiveSciences, Medical School, Newcastle University, Newcastle upon TyneIntroduction: Oestrogens are critical agents that mediate diverse aspects ofbreast tumourigenesis via ER-mediated regulation of the expression of selectgenes. SLC12A2 encodes an electroneutral Na + K + -2Cl - cotransporter and wasidentified as an oestrogen-regulated gene in the present study. SLC12A2 isexpressed in secretory epithelial cells and diverse tissues. SLC12A2 is a markerof murine breast epithelial cells and has a role in breast morphogenesis.Methods: Human breast cancer cells (EFF-3, EFM-19 & MCF-7) were grownto 70% confluence and deprived of oestrogens for 7 days before treatment with10 -9 M oestradiol. RNA was extracted according to Affymetrix protocols priorto hybridization to Affymetrix Hu U133 Plus 2.0 GeneChips. Quantitative realtimePCR (qPCR) was then performed to validate SLC12A2 oestrogenregulationin breast cancer cell lines and expression in snap-frozen invasivebreast carcinoma specimens (n=18).Results: 2800 oestrogen-regulated transcripts were identified, including PgR,TFF1, IGF1R and IRS1. SLC12A2 is a novel oestrogen-regulated gene that wasconfirmed by qPCR to be down-regulated upon oestradiol treatment.Differential gene expression was observed to be time and oestradiol doseresponsive. SLC12A2 mRNA was expressed in a panel of invasive breastcarcinoma samples at mean higher levels in ER+ tumours compared withER- tumours (p=0.0872).Conclusions: SLC12A2 mRNA expression is decreased by oestradiol inoestrogen-responsive breast cancer cells. SLC12A2 mRNA is expressed ininvasive breast carcinoma tissue but this does not show a statistically significantassociation with ER-status.P32Expression of the Co-activator NCOA3 in Breast CancerRA Walker 1 ,SLambe 1 ,JA Shaw 1 .1 University of LeicesterA cDNA microarray comparing cancers from women of 35 yrs and normalbreast identified genes that were upregulated in cancers. One of these wasNCOA3 which has been found to have increased expression in breast cancer.Although it is a steroid receptor co-activator, there are conflicting reports as towhether increased expression occurs in oestrogen receptor (ER) positive ornegative cancers. This study examined expression in breast cancers fromdifferent age groups with known ER status.Expression of NCOA3 in 6 breast cell lines, normal breast organoids and 21frozen breast cancers (10 < 35 yrs, 11 >35yrs) was analysed by quantitative RT-PCR. Protein analysis was by western blotting of the same cell lines andorganoids, and by immunohistochemistry of normal breast and 56 breastcancers (20 yrs).There was higher expression by qPCR in the breast cancers from youngerwomen compared to those >35 (P=0.006). Higher mRNA expression was foundin the ER positive cancer cells, with westren blotting showing protein in thesame cells.Immunohistochemistry showed NCOA3 to be nuclear with somecytoplasmic staining. 25/56 had staining for NCOA3. In contrast to the qPCRthere were fewer positive cases in the