Characterisation and predictive value of epidermal growth factor receptor status using quantitative real-time PCR combined with immunohistochemistry on non-small cell lung cancer specimens.
The frequency of increased EGFR-mRNA expression was determined in 57 patients suffering from NSCLC by applying quantitative real-time PCR. The findings were correlated with clinical parameters and the immunohistochemical (IHC) markers EGFR, c-erbB-2, c-erbB-3, Ki-67 and p53 on cryostat sections. Of the patients 46% showed increased EGFR-mRNA, 35% revealed an increased IHC-EGFR expression; 16% of the patients showed a combined positivity and 35% a combined negativity when applying both methods, and 17 (30%) of the cases revealed increased EGFR-mRNA without IHC-EGFR expression. This subgroup was characterised by p53 coexpression and the highest frequency of deaths (35% vs. 20%) indicating a more aggressive tumour type. In contrast to IHC - where positivity was seen predominantly in squamous cell carcinomas (48% vs. 27%) - EGFR-mRNA expression was observed equally in both histological subtypes (48% vs. 43%). PCR-EGFR and IHC-EGFR tumour typing identifies different tumour characteristics with different clinical courses. Whether this combined typing could help to identify patients who respond to anti-EGFR therapies is worth further testing.
Hilbe
Wolfgang
W
Department of Internal Medicine, University Hospital, A-6020 Innsbruck, Austria. wolfgang.hilbe@uibk.ac.at
Dlaska
Margit
M
Dirnhofer
Stephan
S
Duba
Hans-Christoph
HC
Eisterer
Wolfgang
W
Oberwasserlechner
Frieda
F
Mildner
Andreas
A
Schmid
Thomas
T
Ammann
Karlheinz
K
Thaler
Josef
J
Wöll
Ewald
E
D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism* / Q000401:mortality; D066246:ErbB Receptors / Q000096:biosynthesis* / Q000737:chemistry*; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000096:biosynthesis; D008175:Lung Neoplasms / Q000378:metabolism* / Q000401:mortality; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014158:Transcription, Genetic; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
D019394:Ki-67 Antigen; D012333:RNA, Messenger; D016159:Tumor Suppressor Protein p53; D066246:ErbB Receptors