Her-2/neu expression in salivary duct carcinoma: an immunohistochemical and chromogenic in situ hybridization study.
Salivary duct carcinoma (SDC) shares significant morphologic and immunophenotypic overlap with ductal carcinoma of the breast, including HER-2/neu expression. Previous studies have detected HER-2/neu at the protein level in SDCs; however, no study, to date, has assayed whether this expression is related to gene amplification detected by chromogenic in situ hybridization (CISH). Formalin-fixed, paraffin-embedded tissue sections from 12 previously diagnosed SDCs were evaluated by immunohistochemistry (IHC) and CISH for HER-2/neu status. Result concordance was seen in all 12 cases. A total of 4 SDCs were positive by IHC; all 4 cases showed amplification with CISH. The remaining 8 cases were negative by IHC and showed no gene amplification with CISH. SDCs in this study show HER-2/neu overexpression on both the protein and gene levels in approximately 30% of cases. These findings suggest a role may exist for Herceptin (trastuzumab) based therapy in some SDC patients.
Johnson
Christopher J
CJ
Department of Pathology, University of Iowa Hospitals and Clinics, Iowa City, IA, USA.
Barry
Michelle B
MB
Vasef
Mohammad A
MA
Deyoung
Barry R
BR
D044584:Carcinoma, Ductal / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization / Q000379:methods; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D012468:Salivary Gland Neoplasms / Q000378:metabolism*
D018719:Erb-b2 Receptor Tyrosine Kinases