Thrombotic risk of platinum combination chemotherapy with and without immune checkpoint inhibitors for advanced non-small cell lung cancer: a nationwide inpatient database study

Abstract

ObjectivesTo determine the associated thromboembolism risk with adding immune checkpoint inhibitors (ICI) to platinum combination chemotherapy compared with platinum combination chemotherapy alone in patients with advanced non-small cell lung cancer.Materials and methodsThis study identified 75,807 patients with advanced non-small cell lung cancer from the Japanese Diagnosis Procedure Combination database who started platinum combination chemotherapy between July 2010 and March 2021. The incidence of venous thromboembolism (VTE), arterial thromboembolism (ATE), and all-cause mortality within 6 months after commencing platinum combination chemotherapy was compared between patients receiving chemotherapy with ICI (ICI group, n = 7,177) and without ICI (non-ICI group, n = 37,903). Survival time analysis was performed using the overlap weighting method with propensity scores to adjust for background factors. The subdistribution hazard ratio for developing thromboembolism was calculated using the Fine-Gray model with death as a competing risk. The hazard ratio for all-cause mortality was also calculated using the Cox proportional hazards model.ResultsOverall, VTE and ATE occurred in 761 (1.0%) and 389 (0.51%) patients, respectively; mortality was 11.7%. Propensity score overlap weighting demonstrated that the subdistribution hazard ratio (95% confidence interval) for VTE and ATE in the ICI group was 1.27 (1.01–1.60) and 0.96 (0.67–1.36), respectively, compared with the non-ICI group. The mortality hazard ratio in the ICI group was 0.68 (0.62–0.74).ConclusionThe addition of ICI to platinum combination therapy was associated with a higher risk of VTE compared with platinum combination therapy alone, while the risk of ATE might be comparable.