title: Different HER2 protein expression profiles aid in the histologic differential diagnosis between urothelial carcinoma in situ (CIS) and non-CIS conditions (dysplasia and reactive atypia) of the urinary bladder mucosa.
abstract: We evaluated HER2 expression profiles in 32 carcinoma in situ (CIS) and 31 non-CIS conditions (5 dysplasia and 26 reactive atypia) of the urinary bladder mucosa by applying breast cancer scoring rules. In situ hybridization was performed on tissue microarrays to assess HER2 gene amplification status. Our immunoprofiling data disclosed moderate to strong HER2 expression in CIS, including the basal layer of the urothelium, and absent to weak HER2 expression in non-CIS conditions. From the histologic differential diagnostic standpoint, immunostaining for HER2 protein represents a useful adjunct to aid in the delineation between CIS and non-CIS conditions of the bladder mucosa. Pathogenically, aberrant HER2 protein expression in CIS seems to be more commonly associated with polysomy than with gene amplification. From a therapeutic viewpoint, prospective clinical studies should investigate the potential benefit of HER2-targeted therapies in CIS, particularly in cases unresponsive to conventional therapeutic regimens.
authors.affiliation: Institute of Pathology, HELIOS Clinic Bad Saarow, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Gunia
authors.forename: Stefan
authors.initials: S
authors.lastname: Koch
authors.forename: Oliver W
authors.initials: OW
authors.lastname: Hakenberg
authors.forename: Matthias
authors.initials: M
authors.lastname: May
authors.forename: Christoph
authors.initials: C
authors.lastname: Kakies
authors.forename: Andreas
authors.initials: A
authors.lastname: Erbersdobler
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002278:Carcinoma in Situ / Q000175:diagnosis* / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D008297:Male; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis* / Q000235:genetics; D012189:Retrospective Studies; D001743:Urinary Bladder / Q000378:metabolism; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D019459:Urothelium / Q000378:metabolism / Q000473:pathology*
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases