The Cancer Immunotherapy Thromboembolism Assessment: A Novel Score for Predicting Thromboembolic Events in Melanoma Patients Treated With Immune Checkpoint Inhibition

Venous and arterial thromboembolic events (TEEs) represent a substantial threat for melanoma patients treated with immune checkpoint inhibition (ICI) and have a significant impact on quality of life, therapy outcome, and survival. Existing risk assessment models for predicting TEE risk have been developed for other patient collectives and show poor performance in melanoma patients treated with ICI. In this cohort analysis, 358 AJCC stage III/IV melanoma patients treated with ICI between April 2013 and July 2024 at the University Skin Cancer Center Hamburg and the University Medical Center Mannheim were included. TEEs were recorded and classified as thrombosis including vein thrombosis, pulmonary embolism, stroke, or transient ischemic attack. Clinical and laboratory data were determined before the start and prospectively during the treatment. We identified elevated serum baseline D-Dimer (p = 0.0098) and elevated C-reactive protein (p = 0.0042) concentrations and measurable tumor burden (p = 0.0039) as main risk factors for the occurrence of TEE. For the final model, points were assigned for the Cancer Immunotherapy Thromboembolism Assessment (CITA) according to the impact of those variables using multiple logistic regression. The score was calculated for each patient. For the high-risk group, the negative predictive value (NPV) was 97.2%; sensitivity and specificity were 83.3% and 62%, respectively. The CITA risk score provides a simple and easily calculated risk assessment tool for stratifying melanoma patients based on their risk for TEE after ICI initiation, but prospective validation is needed before clinical use can be recommended.