title: HER2 status in primary stage T1 urothelial cell carcinoma of the urinary bladder.
abstract: OBJECTIVE
  The HER2 receptor is involved in pathways essential for cell proliferation, and is an important predictive and prognostic factor in breast cancer. HER2 probably plays a critical role in many types of cancer, including urothelial carcinoma of the bladder (UCB). Stage T1 UCB exhibits heterogeneous clinical behaviour, and the frequency of HER2 expression in such disease has not been thoroughly examined. The aim of this study was to use an immunohistochemical technique to evaluate the frequency of HER2 expression in a defined population-based cohort of patients registered as having primary stage T1 UCB.
  
  
  METHODS
  The initial study population comprised 285 patients registered as having primary stage T1 UCB. The original histological specimens were re-evaluated with regard to T stage and World Health Organization grade. Hospital records provided information on tumour size, multiplicity, possible presence of histologically proven recurrence and progression. The patients were followed for at least 5 years or until death. In tumours still considered stage T1 after re-evaluation, HER2 was investigated by immunohistochemistry of paraffin-embedded material and scored according to the guidelines used in breast cancer.
  
  
  RESULTS
  After histopathological re-evaluation, 201 patients were still T1 UCB and could be investigated regarding HER2 expression. HER2 overexpression was observed in 25 of those patients (12.4%). HER2 status was not significantly associated with recurrence or progression.
  
  
  CONCLUSIONS
  HER2 was overexpressed in 12.4% of the present cohort of patients with primary stage T1 UCB. There was no significant association between tumour HER2 status and prognosis.
authors.affiliation: Pathology Clinic, Division of Molecular and Immunological Pathology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Östergötland County Council, Linköping, Sweden. hansolsson33@telia.com
authors.forename: Hans
authors.initials: H
authors.lastname: Olsson
authors.forename: Ing-Marie
authors.initials: IM
authors.lastname: Fyhr
authors.forename: Per
authors.initials: P
authors.lastname: Hultman
authors.forename: Staffan
authors.initials: S
authors.lastname: Jahnson
mesh_terms: D000368:Aged; D002277:Carcinoma / Q000378:metabolism* / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000378:metabolism*; D009367:Neoplasm Staging; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D047368:Tumor Burden; D001749:Urinary Bladder Neoplasms / Q000378:metabolism* / Q000473:pathology*
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human