[Immunotherapy of esophageal, GEJ and gastric tumors].

Gastroesophageal cancers still rank among the leading causes of cancer-related death. With the introduction of immunotherapy, the treatment strategy has evolved. In the neoadjuvant setting for gastroesophageal junction (GEJ) and gastric adenocarcinoma, the results of the MATTERHORN clinical trial, presented at this year's ASCO meeting, are expected to shift future treatment strategies. In esophageal tumors, adjuvant nivolumab is used. In metastatic disease, depending on the histological subtype, molecular testing such as PD-L1 CPS and TPS, HER2, and MSI-H is required to determine the treatment decision. In the metastatic setting, combinations of nivolumab or pembrolizumab with fluoropyrimidine- and platinum-based chemotherapy have improved survival. Among HER2-positive patients, adding pembrolizumab to trastuzumab and chemotherapy - in PDL1 CPS ≥1 cases - has become a new standard. A special mention must be made of MSI-H tumors, in which immunotherapy is highly effective, and adjuvant chemotherapy is not recommended according to current guidelines.