ErbB-2 expression and its association with other biological parameters of breast cancer among Indian women.
OBJECTIVE
Overexpression of the epidermal growth factor receptor family genes, which include ErbB-1, 2, 3 and 4, has been implicated in a number of cancers. We have studied the extent of ErbB-2 overexpression among Indian women with sporadic breast cancer.


METHODS
Immunohistochemistry and genomic polymerase chain reaction (PCR) were used to study the ErbB2 overexpression. ErbB2 status was correlated with other clinico-pathological parameters, including patient survival.


RESULTS
ErbB-2 overexpression was detected in 43.2% (159/368) of the cases by immunohistochemistry. For a sub-set of patients (n = 55) for whom total DNA was available, ErbB-2 gene amplification was detected in 25.5% (14/55) of the cases by genomic PCR. While the ErbB2 overexpression was significantly higher in patients with lymphnode (chi2 = 12.06, P < or = 0.001), larger tumor size (chi2 = 8.22, P = 0.042) and ductal carcinoma (chi2 = 15.42, P < or = 0.001), it was lower in patients with disease-free survival (chi2 = 22.13, P < or = 0.001). Survival analysis on a sub-set of patients for whom survival data were available (n = 179) revealed that ErbB-2 status (chi2 =25.94, P < or = 0.001), lymphnode status (chi2 = 12.68, P < or = 0.001), distant metastasis (chi2 = 19.49, P < or = 0.001) and stage of the disease (chi2 = 28.04, P < or = 0.001) were markers of poor prognosis.


CONCLUSIONS
ErbB-2 overexpression was significantly greater compared with the Western literature, but comparable to other Indian studies. Significant correlation was found between ErbB-2 status and lymphnode status, tumor size and ductal carcinoma. ErbB-2 status, lymph node status, distant metastasis and stage of the disease were found to be prognostic indicators.
Vaidyanathan
K
K
Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore-12, India.
Kumar
P
P
Reddy
C O
CO
Deshmane
V
V
Somasundaram
K
K
Mukherjee
G
G
D001943:Breast Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000235:genetics* / Q000401:mortality / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D018734:Genes, erbB-2; D006801:Humans; D007150:Immunohistochemistry; D007194:India; D009367:Neoplasm Staging; D016133:Polymerase Chain Reaction; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis / Q000235:genetics*
D018719:Erb-b2 Receptor Tyrosine Kinases