Abstract:Objective To investigate the incidence and risk factors of multi-organ immune-related adverse events (irAEs) induced by tislelizumab in patients with malignant tumors.Methods A total of 149 patients with malignant tumor who received tislelizumab treatment in the Department of Oncology from October 2022 to October 2024 were included. Patients who developed irAEs were assigned to the observation group (n =43), while those who did not develop irAEs were assigned to the control group (n =106). A comparison of clinical traits was made between the two groups. Multivariable Logistic regression analysis was used to identify factors influencing the occurrence of irAEs, and the diagnostic performance was assessed using receiver operating characteristic (ROC) curve analysis.Results The incidence of irAEs was 28.86% (43/149). In the observation group, the proportions of patients with non-small cell lung cancer, those receiving combination therapy, and those with a disease course ≥ 1 year were all significantly higher than those in the control group (P < 0.05). Additionally, the neutrophil-to-lymphocyte ratio (NLR) was significantly lower (P <0.05), while the platelet-to-lymphocyte ratio (PLR) was significantly higher in the observation group compared to those in the control group (P < 0.05). There was no statistically significant difference between the two groups in terms of sex distribution, age, BMI, comorbidities, smoking history, alcohol consumption history, TNM stage, EOS, and ALC (P > 0.05). Multivariable Logistic regression analysis revealed that non-small cell lung cancer [O^R = 9.915 (95% CI: 1.230, 79.904) ], combination therapy [O^R = 15.786 (95% CI: 1.515, 164.457) ], disease duration ≥ 1 year [O^R = 6.702 (95% CI: 1.513, 29.682) ], decreased NLR [O^R = 0.038 (95% CI: 0.006, 0.260) ], and increased PLR [O^R = 1.093 (95% CI: 1.046, 1.143) ] were all independent risk factors for the development of irAEs (P < 0.05). ROC curve analysis based on the multivariable Logistic regression model demonstrated a sensitivity of 93.0% (95% CI: 0.809, 0.985) and a specificity of 92.5% (95% CI: 0.857, 0.967) for predicting the occurrence of irAEs.Conclusion The occurrence of irAEs in patients with malignant tumors treated with tislelizumab is closely associated with tumor type, treatment regimen, and specific immune-related biomarkers.