RESUMO
BACKGROUND: Cancer-associated thrombosis (CAT) is a major cause of mortality in cancer patients. Immune checkpoint inhibitors (ICIs) have been associated with multiple side effects including CAT. The aim of this study is to investigate risk factors and prognostic impact associated with CAT events during ICIs treatment. METHODS: This is a multi-center retrospective study that included stage IV cancer patients treated with ICIs. RESULTS: We identified 552 cancer patients treated with ICIs. During follow-up time, 58 (10.5%) patients developed 67 venous thromboembolism (VTE) events while on ICIs. Anticoagulation use at the time of ICIs treatment start was associated with significantly higher VTE incidence rate (IRR: 2.23). No significant difference in VTE IRR was observed depending on response to ICIs treatment, aspirin use, or Khorana VTE risk score. Melanoma as primary cancer, Khorana score, ECOG status, and anemia at baseline were able to predict mortality. CONCLUSIONS: The incidence of CAT in stage-IV cancer patients treated with ICIs was higher in our study compared to previous reports. Control group of patients who did not receive ICIs is needed for better identification of CAT risk factors. Khorana score was a good predictor of mortality but not CAT risk and needs to be further validated in a homogenous group of patients.