Laboratory diagnosis of the thrombophilic state in cancer patients.

Perturbations of coagulation in cancer patients have been described for a long time. In up to 90% of cancer patients "routine" blood tests are abnormal leading to a hypercoagulable state in these patients. Among these tests are an increase in clotting factors, fibrinogen, fibrinogen/fibrin degradation products, and thrombocytosis. Markers of the activation of coagulation have been developed, and levels of FPA, F1+2, TAT, and D-Dimer have been found higher in cancer patients. More specific procoagulant activities in cancer (CP and TF) have also been described and can be measured but none of them have any predictive value for the occurrence of venous thromboembolism in these patients. Consistent with this hypercoagulable state in cancer is the finding that most cancer patients have reduced plasma levels of inhibitors of coagulation. These complex abnormalities are clinically expressed as thrombosis, low-grade or fulminant DIC which can be assessed by different laboratory tests, and as hemorrhage when the fibrinolysis system is impaired. However, no studies have shown to date a relationship between these abnormalities of the coagulation tests and the clinical expression in any single individual. Because these patients are at high risk for thrombosis in special conditions such as surgery or during chemotherapy, prophylaxis with various forms of heparin are recommended.