HER-2 DNA quantification of paraffin-embedded breast carcinomas with LightCycler real-time PCR in comparison to immunohistochemistry and chromogenic in situ hybridization.
OBJECTIVE
To compare the detection of HER-2 status by real-time PCR, on paraffin-embedded breast carcinomas, in respect to immunohistochemistry (IHC) and chromogenic in situ hybridization (CISH).


METHODS
Paraffin-embedded breast carcinomas collected from 85 patients diagnosed with early stage breast cancer were analyzed for HER-2 gene amplification by real-time PCR and CISH, as well as for HER-2 protein expression by IHC.


RESULTS
HER-2 gene amplification was observed in 19 (22.4%) of 85 breast cancer patients by real-time PCR and in 19 (22.4%) of 85 patients by CISH. Strong (3+) HER-2 protein over-expression was observed in 13 (15.3%) out of 85 patients. Moreover, there were 4 out of 85 (4.7%) patients that had moderate (2+) HER-2 protein over-expression, while 68 out of 85 (80%) patients had no HER-2 protein over-expression by IHC. There were strong concordance rates between real-time PCR and IHC (79/85, 92.9%, p<0.0001) and real-time PCR and CISH (77/85, 90.6%, p<0.0001). The concordance rate between the three methods was 90.6% (p<0.0001).


CONCLUSIONS
Our data show that the results obtained for amplification of HER-2 by real-time PCR on the LightCycler are comparable to those obtained by IHC and CISH.
Ntoulia
Maria
M
Laboratory of Analytical Chemistry, Department of Chemistry, University of Athens, Athens 15771, Greece.
Kaklamanis
Loukas
L
Valavanis
Christos
C
Kafousi
Maria
M
Stathopoulos
Efstathios
E
Arapantoni
Petroula
P
Mavroudis
Dimitris
D
Georgoulias
Vassilis
V
Lianidou
Evi S
ES
D001943:Breast Neoplasms / Q000378:metabolism*; D002277:Carcinoma / Q000378:metabolism*; D002863:Chromogenic Compounds / Q000737:chemistry; D004247:DNA / Q000032:analysis; D004273:DNA, Neoplasm / Q000032:analysis*; D005784:Gene Amplification; D018628:Gene Dosage; D018734:Genes, erbB-2; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D017403:In Situ Hybridization / Q000379:methods; D016612:Paraffin Embedding; D016133:Polymerase Chain Reaction / Q000379:methods*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism
D002863:Chromogenic Compounds; D004247:DNA; D004273:DNA, Neoplasm; D018719:Erb-b2 Receptor Tyrosine Kinases