Molecularly-targeted therapy of gastric cancer

Gastric cancer is a heterogeneous malignancy with expression of many molecular factors. Trastuzumab is the first biologic drug (targeted therapy) that has shown benefits in terms of increased median overall survival. Trastuzumab in combination with chemotherapy is indicated in metastatic gastric or gastrooesophageal junction cancer in patients with no prior exposure to systemic anticancer therapy for disseminated disease and with HER2 protein overexpression (score of IHC 3+) regardless of HER2 gene copy number and with expression of 2+ combined with HER2 gene amplification, although clinical benefits in this group are much less evident.