Gastric cancer represents the fifth most common
malignancy and third most common cause of
cancer deaths worldwide. There are two major types of gastric
carcinoma: enteric type and diffuse type. Diffuse type
gastric cancer is frequently associated with the mutations in
E-cadherin coding gene CDH1. In cases of CDH1 mutations complete
gastrectomy is indicated. CDH1 mutations are reflected with
CDH1 protein loss by immunohistochemistry. The relationship between CDH1 mutations and other markers of tumour aggressiveness, such as tumour proliferation index and the presence of p53 mutations and Her2 amplification is not well studied. Therefore, the aim of our study was to analyse the correlation between CDH1 loss and the expression of Ki67 proliferation marker, mutant
oncoprotein p53 and Her2. Standard immunohistochemistry was used to detect the following
antigens: CDH1 (MCH-38, Invitrogen), Ki67 (EP5, Bio SB), p53 (DO-7, Leica) and Her2 (EP3, Bio SB). The study results showed that CDH1 mutations, reflected with
CDH1 protein loss by immunohistochemistry are detected in 40% of diffuse gastric
carcinomas, whilst it is not detected in enteric type gastric
carcinomas. Diffuse gastric
carcinomas with CDH1 mutations are characterised with more aggressive phenotype, particularly with the presence of higher Ki67 labelling index, p53 mutations and the presence of Her2 positivity. In cases of histological diagnosis of diffuse gastric
carcinoma CDH1 testing is recommended.