Abstract

Addition of Trastuzumab in management of advanced gastric and gastroesophageal carcinomas, has provided benefit in overall survival of those with Her2 positive tumors. For eligibility of patients for this therapy, Her2 test is done. Following breast carcinomas, Her2 testing in gastric carcinomas are also added to the routine work of pathology laboratories. Although Her2 test in gastric carcinomas has similar features with that of breast, it has some aspects to be known well. These aspects have arisen mainly because heterogenous Her2 positivity and basolateral settling of the receptors in gastric carcinoma cells. Although Her2 immunohistochemical and in situ hybridisation tests are among routine tests of most laboratories, scoring criteria are complex and need experience for accuracte results. In achieving accurate results in these tests, prenanalytical as well as the analytical conditions, are also effective.