The role of chemotherapy in unresectable or metastatic adenocarcinoma of the stomach and gastroesophageal junction

Gastric cancer including gastroesophageal junction adenocarcinomas are most challenging and deadly cancers of the gastrointestinal tract. Gastric cancer has a fatality-to-case ratio of 0.66, translating that nearly two thirds of newly diagnosed patients will have disseminated disease and in need of systemic therapy. Advanced gastric adenocarcinoma (AGC) is a heterogenous disease with differences in geographical distribution, histopathology, and molecular subtypes. Fluoropyrimidines (5-FU, S-1, and capecitabine), platinum compounds (cisplatin, oxaliplatin), taxanes (paclitaxel, docetaxel), and the topoisomerase inhibitory irinotecan are active drugs against AGC. The combination of fluoropyrimidines with a platinum compound is the optimal first-line treatment. Trastuzumab (given in combination with chemotherapy for HER2 positive tumors) and ramucirumab are the only targeted agents approved by the food and drug administration for the treatment in AGC for first and second line respectively. Efforts are being directed to harness the immune system with checkpoint inhibitors and to combining these drugs with chemotherapy in clinical trials. Genomic technology advancements might provide us with the tools to create personalized treatment for AGC in the near future with the goal to improve outcomes. In this article we aimed to review current therapeutic regimens for AGC with an update of ongoing clinical trials.