RESUMO
Gastrointestinal (GI) cancers include esophageal, gastric, pancreatic, hepatobiliary, and colorectal malignancies. Immunotherapy has proved to be an important treatment method for cancer, and its use for a wide range of GI malignancies has been evaluated recently. This article discusses the type and mechanism of various immunotherapies under investigation in GI cancer. The study also reviews recent clinical trials, with a particular focus on overall survival, and discusses their achievements and limitations. Immunotherapy has shown efficacy for microsatellite instability high colorectal cancer and some promise in some gastroesophageal junction and gastric cancers. Meanwhile, it has not been effective for pancreatic or neuroendocrine tumors. The identification of novel biomarkers likely will guide selection of therapy for individual patients. Nevertheless, immunotherapy for GI cancers is in its infancy, and many other classes of immune therapies are being developed besides anti-PD1 and anti-PDL1. Thus, although immunotherapy has not seen a dramatic advance to date, it still has great potential.