[Checkpoint Inhibitors in the Treatment of Upper Gastrointestinal Tract Tumors].

Chemotherapy prolongs overall survival (OS) in esophageal (EC) and gastric cancer (GC). Unsatisfactory results of systemic therapy initiated a search for new treatment options. In metastatic disease, a number of targeted drugs were tested; however, several phase III studies assessing receptor tyrosin kinase-related signaling pathways, such as EGFR, MET/HGF or mTOR, failed. Trastuzumab remains the only targeted drug with a known molecular predictor, which extended the OS in metastatic gastric adenocarcinoma and adenocarcinoma of esophago-gastric junction. In the past two years, The Cancer Genome Atlas group published an analysis based on the genomic characteristics of GC and EC. Therefore, a better understanding of tumor biology may be a way towards stratification of treatment based on genetic and molecular characteristics and not merely on anatomical or histological basis. The rapid development in research of anti-tumor immunity and an achievement in the field of checkpoint inhibitors use in malignant melanoma have also enabled research in other cancers, including gastrointestinal malignancies. Checkpoints are part of a comprehensive and complex process of the immune system, and at the same time, the key points in the emergence of tumor tolerance. Their activation protects the organism against autoimmune reactions, but at the same time allows induction of tumor tolerance. Discussing checkpoints include the cytotoxic T-lymphocyte antigen 4 (CTLA-4) and programmed death-1 (PD-1) receptors and the ligand PD-1 receptor, programmed death ligand-1 (PD-L1). In this article, I summarize current findings on the use of anti PD1 agents in EC and GC.Key words: esophageal cancer - stomach cancer - checkpoint inhibitors This work was supported by the project of Ministry of Health of the Czech Republic No. 15 P03- 17-29389A and by projects LO1413, DRO and LM15089 BBMRI-CZ. The author declares she has no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 17. 9. 2017Accepted: 5. 11. 2017.