Incidence of thromboembolic events in non-small cell lung cancer patients treated with immune checkpoint inhibitors: A systematic review and meta-analysis

The incidence of thromboembolic events (TEs) in non-small cell lung cancer (NSCLC) patients treated with immune checkpoint inhibitors (ICIs) has rarely been reported. The MEDLINE, EMBASE, and the Cochrane Library databases were searched. The primary outcome was the incidence of TEs, and the secondary outcome was the relationship between TEs and overall survival (OS) following ICI therapy. A subgroup analysis of TE incidents was performed according to the TE type and combination regimens. The I2 statistic was used to determine the heterogeneity, and funnel plots and Egger’s test were used to assess publication bias. A total of 16,602 patients with NSCLC in 63 experimental arms were included in the analysis. The rate of TEs ranged from 0.1% to 13.8%, and the pooled overall incidence of all-grade TEs was 3% (95% confidence interval [CI], 2%–4%). The pooled rate of high-grade TEs was 1% (95% CI, 1%–2%). The venous and arterial TE rates were 3% (95% CI, 2%–4%) and 1% (95% CI, 1%–2%), respectively. Patients who received immunotherapy + chemoradiotherapy had the highest incidence of TEs (7%). The TE pooled rate was higher in patients treated with combined ICIs than in those treated with mono ICIs (4% vs. 2%). The OS was lower in patients with TEs than in those without TEs (hazard ratio, 1.4; 95% CI, 1.02%–1.92%). The incidence of TEs in NSCLC patients treated with ICIs was reasonable. Nonetheless, clinicians must be aware of potential thrombotic complications and treat them promptly.