[HER2 gene amplification and overexpression in advanced gastric cancer].
BACKGROUND
Overexpression/amplification of the HER2 gene in advanced gastric cancer is a predictor of response to adjuvant therapy with monoclonal antibodies.


OBJECTIVE
To determine the frequency of HER2 gene overexpression and amplification in advanced gastric cancer.


METHODS
One hundred nine advanced gastric cancer biopsy specimens, from 76 men and 33 women aged 67 ± 14 and 62 ± 12 years respectively, were selected. Three histological patterns (diffuse, intestinal and mixed) were recognized. Automated immunohistochemistry was performed with monoclonal c-erbB-2 (NCL-356) Novocastra. Fluorescent in situ hybridization (FISH) for HER2 was performed in positive cases.


RESULTS
In 39% of cases, immunohistochemical staining was negative. It was 1+, 2+ and 3+ positive in 15, 36 and 11% of cases, respectively. It was positive in 16% and 3% of intestinal type and mixed carcinomas, respectively. It was negative in all diffuse carcinomas. FISH was performed in 39 (2 +) cases and in 11 (3 +) cases. The gene amplification was positive in two (2 +) and 11 (3 +) cases (11.9%). The overall concordance between immunohistochemical staining and in situ hybridization was 85%.


CONCLUSIONS
In advanced gastric cancer, HER2 gene overexpression or amplification was observed in 11% and 12% of cases, respectively.
Iván
I
Roa
Jeannie
J
Slater
Daniel
D
Carvajal
Kurt
K
Schalper
Gonzalo
G
de Toro
Raúl
R
Ares
Anakaren
A
Game
Jorge
J
León
Xabier
X
de Aretxabala
D000230:Adenocarcinoma / Q000235:genetics* / Q000473:pathology; D000368:Aged; D005260:Female; D005784:Gene Amplification / Q000235:genetics*; D015870:Gene Expression; D018734:Genes, erbB-2 / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D013274:Stomach Neoplasms / Q000235:genetics* / Q000473:pathology; D046888:Tissue Array Analysis