GD2 expression in breast cancer

// Giulia Orsi 1 , Monica Barbolini 1 , Guido Ficarra 2, 3 , Giovanni Tazzioli 1, 3 , Paola Manni 2 , Tiziana Petrachi 1 , Ilenia Mastrolia 1 , Enrico Orvieto 4 , Carlotta Spano 1 , Malvina Prapa 1 , Shaniko Kaleci 5 , Roberto D’Amico 5 , Valentina Guarneri 6 , Maria Vittoria Dieci 6 , Stefano Cascinu 1 , Pierfranco Conte 6 , Federico Piacentini 1, 3, * , Massimo Dominici 1, * 1 Department of Medical and Surgical Sciences for Children and Adults, University-Hospital of Modena and Reggio Emilia, 71-41124 Modena, Italy 2 Division of Pathology, University-Hospital of Modena and Reggio Emilia, 71-41124 Modena, Italy 3 Breast Unit, University-Hospital of Modena and Reggio Emilia, 71-41124 Modena, Italy 4 Department of Pathology, Padua University Hospital, 2-35128 Padua, Italy 5 Department of Diagnostic and Clinical Medicine and Public Health, Statistics Unit, University-Hospital of Modena and Reggio Emilia, 71-41124 Modena, Italy 6 Department of Surgery, Oncology and Gastroenterology, Division of Medical Oncology 2, Istituto Oncologico Veneto IRCCS, Via Gattamelata, 64-35128 Padua, Italy * These authors contributed equally to this work Correspondence to: Massimo Dominici, email: massimo.dominici@unimore.it Keywords: GD2, disialoganglioside, BC, TNBC, metaplastic Received: November 04, 2016      Accepted: March 09, 2017      Published: March 18, 2017 ABSTRACT Breast cancer (BC) is a heterogeneous disease, including different subtypes having diverse incidence, drug-sensitivity and survival rates. In particular, claudin-low and basal-like BC have mesenchymal features with a dismal prognosis. Disialoganglioside GD2 is a typical neuroectodermal antigen expressed in a variety of cancers. Despite its potential relevance in cancer diagnostics and therapeutics, the presence and role of GD2 require further investigation, especially in BC. Therefore, we evaluated GD2 expression in a cohort of BC patients and its correlation with clinical-pathological features. Sixty-three patients with BC who underwent surgery without prior chemo- and/or radiotherapy between 2001 and 2014 were considered. Cancer specimens were analyzed by immunohistochemistry and GD2-staining was expressed according to the percentage of positive cells and by a semi-quantitative scoring system. Patient characteristics were heterogeneous by age at diagnosis, histotype, grading, tumor size, Ki-67 and receptor-status. GD2 staining revealed positive cancer cells in 59% of patients. Among them, 26 cases (41%) were labeled with score 1+ and 11 (18%) with score 2+. Notably, the majority of metaplastic carcinoma specimens stained positive for GD2. The univariate regression logistic analysis revealed a significant association of GD2 with triple-receptor negative phenotype and older age (> 78) at diagnosis. We demonstrate for the first time that GD2 is highly prevalent in a cohort of BC patients clustering on very aggressive BC subtypes, such as triple-negative and metaplastic variants.