HER-2 gene amplification by fluorescence in situ hybridization (FISH) compared with immunohistochemistry (IHC) in breast cancer: a study of 528 equivocal cases
Menée sur 528 échantillons tumoraux prélevés sur des patientes atteintes d'un cancer du sein, cette étude chinoise compare les résultats de deux techniques, l'hybridation par fluorescence in situ et l'immunohistochimie, utilisées pour évaluer l'amplification du récepteur HER2
The concordance rate between fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) on evaluating HER-2/neu status is still controversial, especially for the IHC 2+/equivocal cases. In this study, we investigated the amplification of HER-2/neu gene by FISH in IHC (2+)/equivocal specimens to clarify the correlation between HER-2/neu and clinicopathologic features of breast cancers. HER-2/neu amplification was determined by FISH on 528 specimens of breast carcinomas with equivocal expression of HER-2/neu protein by IHC detection. 65.5 % of IHC 2+ patients were negative for HER-2/neu amplification, 29.0 % were positive and the remaining was equivocal. A statistically significant inverse association was found between hormone receptor expression and HER-2/neu amplification ( P < 0.05). Furthermore, polysomy of CEP17 was detected in 60 % of breast carcinomas. The results highlight the necessity of FISH test for further categorization when breast carcinoma cases are scored 2+ by IHC.
Breast Cancer Research and Treatment , résumé, 2011