INTRODUCTION: Gastric cancer is one of the prominent reasons of cancer death worldwide and in India. The majority of individuals are diagnosed at a late stage. Various chemotherapy regimens have improved overall survival slightly. The HER2 protein, which is overexpressed in many stomach tumours, is a novel therapeutic target. Trastuzumab, a monoclonal antibody that targets HER2, has been found to enhance overall survival in advanced gastric cancer.