Silver-enhanced in Situ Hybridization (SISH) detection assay for HER2 gene status determination in breast carcinoma: A four year experience in our laboratory F. Patakiouta * , G. C. Balis, V. Theodorou, E. Triantafillidou, C. Fotiou, I. Boukovinas, C. Andreadis, G. Sibilidis * "Theagenion" Cancer Hospital, Dept. of Pathology, Thessaloniki, Greece