Background: Compact fibrin clots relatively resistant to lysis are observed in patients at increased risk of venous thromboembolism (VTE) including malignancy. The citrullinated histone H3 (H3Cit) predicts VTE in cancer patients.
Objectives: We performed a cohort study to investigate whether abnormal clot properties predict cancer diagnosis following unprovoked VTE.
Methods: In 369 consecutive patients aged <70 years without malignancy detected during routine screening, we determined plasma clot permeability (Ks ) and clot lysis time (CLT), along with several prothrombotic markers and H3Cit after 2 to 8 months since VTE.
Results: During follow-up (median, 37; interquartile range, 33-39 months), malignancy was diagnosed in 22 patients (6%), who were older. This group had denser fibrin networks (-13% Ks ), impaired fibrinolysis (+25.5% CLT), increased endogenous thrombin potential (ETP,+7%), soluble P-selectin (+40.3%), and H3Cit (+169.2%) measured off anticoagulation after median 4 months since VTE. The Ks and CLT correlated with H3Cit (r = -.58 and r = .31, P < .05, respectively). The Kaplan-Meier survival analysis showed that reduced Ks (the first quartile, ≤6.2 × 10-9 cm2 ), prolonged CLT (the top quartile, >106 min), and higher ETP (the top quartile, >1657 nM × min) were predictors of cancer diagnosed during follow-up. The multivariable Cox proportional hazards model showed that patients with the prothrombotic clot phenotype (low Ks and long CLT) had the highest risk of cancer diagnosis [hazard ratio(HR), 23.4; 95% confidence interval (CI), 6.67-82.15].
Conclusions: Prothrombotic clot properties following unprovoked VTE might help identify patients at risk of a diagnosis of cancer within the first 3 years of follow-up.
Keywords: fibrin; fibrinolysis; malignancy; thrombosis; venous thromboembolism.
© 2019 International Society on Thrombosis and Haemostasis.