ESTRO 2021 Abstract Book

S904

ESTRO 2021

enable automated TILs quantification at scale, facilitating rapid evaluation of immune infiltrate in large BC cohorts with potential to unmask novel topographical features. 1. Zormpas-Petridis et al. Frontiers in oncology. 2021 Jan 20;10: 3052

PO-1086 Identification of highly expressed genes in high risk breast cancer using bioinformatic analysis S. Ghasemi 1 , M. Mobasheri 2 , S.R. Mahdavi 3,5 , H. Mirzaee 4 1 Tarbiat modares university, Medical physic, Tehran, Iran Islamic Republic of; 2 Islamic Azad University- Pharmaceutical Branch, Biotechnology, Tehran, Iran Islamic Republic of; 3 Iran university of medical sciences, medical physics , Tehran, Iran Islamic Republic of; 4 Shahid-beheshti university of medical sciences, Radio- oncology, Tehran, Iran Islamic Republic of; 5 Iran university of medical sciences, Biology research center, Tehran, Iran Islamic Republic of Purpose or Objective Ductal breast cancer such as invasive ductal carcinoma (IDC) and ductal carcinoma in situ (DCIS) is one of the most common pathology in breast cancer. This type of cancer develops with genomic changes in ductal epithelial cells of normal breast tissue. Therefore, determination of gene expression and pathway changes in ductal cells may be associated with increased risk of breast cancer. In the present study, highly expressed genes and pathways in women at high risk for ductal breast cancer were assessed using bioinformatics and microarray data. A microarray dataset (GSE153796) was downloaded from the Gene Expression Omnibus (GEO) database. This dataset contains 29 samples including 9 normal risk samples and 8 high risk samples (12 atypia samples were not considered in this study). Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses were performed. Cytoscape and Gephi software’s were used for the protein- protein interaction (PPI) network and module analysis of upregulated differential expressed genes (uDEGs). Materials and Methods A microarray dataset (GSE153796) was downloaded from the Gene Expression Omnibus (GEO) database. This dataset contains 29 samples including 9 normal risk samples and 8 high risk samples (12 atypia samples were not considered in this study). Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses were performed. Cytoscape and Gephi software’s were used for the protein- protein interaction (PPI) network and module analysis of upregulated differential expressed genes (uDEGs). Results We obtained total 2001 DEGs consist of 258 up-regulated genes. The PPI network and Gephi results showed that the top 11 highly expressed hub genes were ADCY2, RAPGEF4, ENPP3, ITPR1, PLCB4, UMPS, HTR2B, KALRN, GART, EFNB2 and EIF3B with the highest Eigencentrality, degree, closeness and betweenness centrality, respectively. GO and KEGG pathway enrichment analysis suggested that up-regulated DEGs most significantly enriched in Glycosylphosphatidylinositol (GPI)-anchor biosynthesis, Riboflavin metabolism, Insulin secretion, Gap junction, Nicotinate and nicotinamide metabolism, Circadian entrainment, Inflammatory mediator regulation of TRP channels, Cortisol synthesis and secretion, Renin secretion and Thyroid hormone synthesis. Survival analysis based on the GEPIA database found that the expression ADCY2, ITPR1, PLCB4, HTR2B significantly predicted lower overall survival in Breast cancer. Conclusion Collectively, we identified several hub genes and key pathways associated with Breast cancer initiation in women at high risk for ductal breast cancer by analyzing the microarray data on DEGs, which provided a detailed molecular mechanism underlying Breast cancer occurrence and progression and these 11 hub genes could be of potential biomarkers in diagnosis and prevention of breast cancer. PO-1087 Hypofractionated radiotherapy for breast cancer orbital lesion: a multicentric series of 35 patients I. Desideri 1 , L.P. Ciccone 1 , G. Piperno 2 , M. Augugliaro 2 , B.A. Jereczek-Fossa 3 , P. Navarria 4 , L. Dominici 5 , M. Scorsetti 6 , V. Salvestrini 1 , G. Riva 7 , V. Di Cataldo 8 , L. Visani 8 , M. Loi 9 , I. Meattini 10 , L. Livi 10 1 University of Florence, Department of Experimental and Clinical Biomedical Sciences "M. Serio", Florence, Italy; 2 IEO European Institute of Oncology, IRCCS, Division of Radiotherapy, Milan, Italy; 3 University of Milan, Department of Oncology and Hemato-oncology, Milan, Italy. IEO European Institute of Oncology, IRCCS, Division of Radiotherapy, Milan, Italy; 4 Humanitas Research Hospital-IRCCS, Radiotherapy and Radiosurgery department , Rozzano, Milan, Italy; 5 Humanitas Research Hospital-IRCCS, Radiotherapy and Radiosurgery department, Rozzano, Milan, Italy; 6 Humanitas Research Hospital-IRCCS, Rozzano, Milan, Italy; Department of Biomedical Sciences, Humanitas University, Pieve Emanuele , Milan, Italy; 7 National Center for Oncological Hadrontherapy (CNAO), Radiotherapy Unit, Pavia, Italy; 8 Istituto Fiorentino di Cura ed Assistenza, CyberKnife Center, Florence, Italy; 9 Azienda Ospedaliero Universitaria Careggi, Radiation Oncology Unit - Oncology Department, Florence, Italy; 10 University of Florence, Department of Experimental and Clinical Biomedical Sciences "M. Serio". Azienda Ospedaliero Universitaria Careggi, Radiation Oncology Unit - Oncology Department, Florence, Italy Purpose or Objective Orbital metastases in breast cancer (OM-BC) patients (pts) are a rare occurrence. OM-BC are usually symptomatic with a huge impact on quality of life. Local control (LC) might be difficult to obtain because of the proximity of critical structures. Hypofractionated radiotherapy (HFRT) could constitute a viable treatment for OM-BC. Here an Italian multicentric retrospective experience of Radiation Oncology Departments of AOU Careggi Florence, European Institute of Oncology IRCCS Milan and Humanitas Clinical and Research Center IRCCS Rozzano about pts with OM-BC treated with HFRT is presented. Materials and Methods Clinical data records of 35 pts consecutively treated for OM-BC were collected: 7 pts with (volumetric modulated arc therapy) VMAT-HFRT and 28 pts with Cyberknife R (CK) system (Figure 1). LC, objective response