Clinical impact of venous thromboembolism in non-small cell lung cancer patients receiving immunotherapy

BACKGROUND: Prospective investigation on cancer-associated venous thromboembolism (VTE) in non-small cell lung cancer (NSCLC) during treatment with immune checkpoint inhibitors (ICIs) is lacking.

PATIENTS AND METHODS: A prospective real-world study using combined computed tomography venography and pulmonary angiography (CTVPA) to screen patients with NSCLC for VTE (cohort A). A retrospective multicenter cohort without additional screening with CTVPA was included as control (cohort B). A model with VTE as a time-dependent event using competing risk analysis model with death as a competing event was used to evaluate outcomes and differences in cumulative VTE incidences.

RESULTS: Cohort A (n = 146) and cohort B (n = 426) had median follow-up for VTE of 16.5 months (IQR 6.7-35.6). Cumulative VTE events at 1, 3, 6, and 12 months were 7.5 %, 9.6 %, 13.0 %, 14.4 % for cohort A and 1.9 %, 3.8 %, 4.9 %, 5.6 % for cohort B with SHR 2.42 (CI 95 % 1.37-4.27) p = 0.0024. Recurrent VTE comprised 52 % and 37 %, respectively. In multivariate overall survival analysis, VTE was significantly associated with impaired OS (HR 2.12 CI 95 % [1.49-3.03], p < 0.0001). Risk factors for VTE comprised prior VTE and ICI administered in first line.

CONCLUSION: Cumulative VTE incidence in NSCLC patients following palliative ICI may be significantly higher than reported in randomised clinical trials and retrospective real-world reports. VTE development during ICI impair OS significantly. Thus, more focus on VTE during ICI is warranted to optimise both prevention and management of VTE. Whether there is a causal relationship between VTE and ICI remains to be explored.