Immune checkpoint inhibitors combined with HER-2 targeted therapy in HER-2 positive gastroesophageal cancer.

GEC is one of the most common cancers and has become a significant health burden worldwide. HER-2 is a proto-oncogene, amplified or overexpressed in different tumors, and associated with a worse prognosis. Trastuzumab plus chemotherapy is the current standard treatment for advanced HER-2 positive GEC. However, it still does not benefit well all patients. HER-2 targeted therapy can up-regulate the expression of PD-1, CTL-4, and TAMs in the tumor microenvironment, strengthen the ADCC process, and enhance the efficacy of immunotherapy. While immune checkpoint inhibitors could reduce drug resistance to anti-HER-2 drugs. Moreover, immunotherapy combined with HER-2 targeted therapy in HER-2 positive GEC has shown perceptible efficacy and acceptable side effects in clinical trials and is regarded as a new therapeutic strategy for GEC. However, there remain significant challenges and requires more research to improve the survival benefit of this therapeutic approach.