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

BACKGROUND 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. METHODS Data were obtained from the Hospital Information System (HIS) of the Department of Digestive Oncology (Henan Cancer Hospital) between January 2019 and December 2019. Inclusion criteria included patients receiving the same PD-1 inhibitor continuously for advanced or recurrent/metastatic digestive system tumors. Indicators including age, sex, clinical diagnosis, height, weight, gene status, PD-1 inhibitors, treatment regimen, medication cycle, efficacy evaluation results, and adverse reactions were analyzed retrospectively. The clinical outcomes were progression-free survival (PFS) and safety. RESULTS A total of 2,767 patients were discharged from HIS, of which 64 (37 male/27 female) were included in this study. Thirty-eight (59.4%) of the patients were aged