title: Discordance rate of HER2 status in primary gastric carcinomas and synchronous lymph node metastases: a multicenter retrospective analysis.
abstract: BACKGROUND
  The assessment of human epidermal growth factor receptor 2 (HER2) gene amplification is essential in order to identify those patients affected by advanced gastric cancer who may benefit from Trastuzumab targeted therapy.
  
  
  METHODS
  With the aim to investigate the concordance rate in HER2 status between primary gastric carcinoma (GC) and synchronous lymphnode metastases, we investigated HER2 status in a cohort of 108 surgical formalin-fixed paraffin-embedded specimens of GC and matched synchronous metastatic lymph nodes collected from three different units of Anatomic Pathology in southern of Italy. Fleiss-Cohen weighted k statistics were used to assess the concordance rate of HER2 status.
  
  
  RESULTS
  HER2 amplification was observed in 17% of primary GCs and the overall concordance rate with corresponding nodal metastases was 90.74%. Changes in HER2 status between primary GC and matched synchronous metastases were evidenced in 10 (9.26%) cases. Of these, 6 cases were HER2 amplified in the primary GC and not amplified in the metastases, while 4 were HER2 not amplified in the primary tumour and amplified in the lymph node metastases.
  
  
  CONCLUSIONS
  Although at present the simultaneous determination of HER2 in advanced gastric cancer and corresponding metastatic lymph nodes is not mandatory, the possibility that the synchronous metastases of GC have a different HER2 status from that of the primary tumour is of remarkable significance; Indeed this may have influence on the therapeutic management and prognosis of the patients.
authors.affiliation: Department of Human Pathology "Gaetano Barresi", Section of Anatomic Pathology, University of Messina, Messina 98123, Italy. calaienco@hotmail.com.
authors.forename: Antonio
authors.initials: A
authors.lastname: Ieni
authors.affiliation: Department of Human Pathology "Gaetano Barresi", Section of Anatomic Pathology, University of Messina, Messina 98123, Italy. vbarresi@unime.it.
authors.forename: Valeria
authors.initials: V
authors.lastname: Barresi
authors.affiliation: Department "G.F. Ingrassia", Section of Anatomic Pathology, University of Catania, Catania 95123, Italy. rosario.caltabiano@unict.it.
authors.forename: Rosario
authors.initials: R
authors.lastname: Caltabiano
authors.affiliation: Department of Medicine and Surgery, University of Salerno, Salerno 84131, Italy. alessia.caleo@unisa.it.
authors.forename: Alessia
authors.initials: A
authors.lastname: Caleo
authors.affiliation: Department of Diagnostic Medicine, Clinics and Public Health, Section of Pathologic Anatomy, University of Modena, Modena 41121, Italy. reggiani.luca@policlinico.mo.it.
authors.forename: Luca Reggiani
authors.initials: LR
authors.lastname: Bonetti
authors.affiliation: Department "G.F. Ingrassia", Section of Anatomic Pathology, University of Catania, Catania 95123, Italy. lanzafas@unict.it.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Lanzafame
authors.affiliation: Department of Medicine and Surgery, University of Salerno, Salerno 84131, Italy. pzeppa@unisa.it.
authors.forename: Pio
authors.initials: P
authors.lastname: Zeppa
authors.affiliation: Department of Human Pathology "Gaetano Barresi", Section of Anatomic Pathology, University of Messina, Messina 98123, Italy. rosariocaruso@tin.it.
authors.forename: Rosario Alberto
authors.initials: RA
authors.lastname: Caruso
authors.affiliation: Department of Human Pathology "Gaetano Barresi", Section of Anatomic Pathology, University of Messina, Messina 98123, Italy. tuccari@unime.it.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Tuccari
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology*
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human