Programmed cell death protein-1 inhibitors in the treatment of digestive system tumors in Chinese population: an observational study of effectiveness and safety

Tumor of the digestive system is a common malignancy with high morbidity and mortality. Although programmed cell death-1 (PD-1) inhibitors have become an effective treatment strategies for many kinds of tumors, there is still some uncertainty in digestive tumors, including: (I) therapeutic effects of PD-1 inhibitors are relatively limited; (II) responses of digestive system tumors to immunotherapies are highly heterogeneous. In the present study, we investigated the outcomes of PD-1 inhibitors for digestive system tumors in Chinese patients to analyze factors that may affect the effects of immunotherapies in digestive system tumors.