EGFR in gastric carcinomas: prognostic significance of protein overexpression and high gene copy number.
OBJECTIVE
Epidermal growth factor receptor (EGFR) expression has been observed in a variety of solid tumours with the potential of new targeted therapeutic agents. The aim was to evaluate the EGFR status of gastric carcinoma (GC) using immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH).


RESULTS
The EGFR status was evaluated in GC tissues from 511 patients using IHC and FISH. In addition, the clinicopathological characteristics were examined and the results were compared with the EGFR status. One hundred and forty cases (27.4%) showed EGFR overexpression by IHC. EGFR overexpression was associated with older age (P = 0.001), moderately or poorly differentiated histology (P = 0.001) and higher stage disease (P = 0.046). Sixteen cases (3.1%) showed high polysomy and 12 cases (2.3%) had gene amplification by FISH. The correlation between IHC and FISH results was statistically significant (P < 0.001). The patients with GC who had EGFR overexpression had an unfavourable prognosis and multivariate analysis showed that EGFR overexpression was a possible independent unfavourable prognostic factor.


CONCLUSIONS
EGFR overexpression was observed in a subset of cases with GC and was associated with an unfavourable prognosis. It will be important to evaluate EGFR status to interpret future clinical trials properly using EGFR targeted agents.
Kim
M A
MA
Department of Pathology, Seoul National University College of Medicine, Seoul, Korea.
Lee
H S
HS
Lee
H E
HE
Jeon
Y K
YK
Yang
H K
HK
Kim
W H
WH
D000368:Aged; D002277:Carcinoma / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D066246:ErbB Receptors / Q000235:genetics* / Q000378:metabolism; D005260:Female; D018628:Gene Dosage; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D016019:Survival Analysis
D066246:ErbB Receptors