Gouin-Thibault I, Achkar A, Samama M M
Laboratoire d'Hématologie, Groupe hospitalier Charles Foix-Jean Rostand, Ivry-sur-Seine, France.
Acta Haematol. 2001;106(1-2):33-42. doi: 10.1159/000046587.
Thrombosis and disseminated intravascular coagulation are common complications of cancer. Specific conditions associated with cancer such as stasis due to immobilization or blood flow obstruction, surgery, infections, endothelium damage due to chemotherapeutic agents and abnormalities of blood coagulation contribute to the hypercoagulable and thrombophilic state of cancer patients. This procoagulant state in cancer arises mostly from the capacity of tumor cells to express and release procoagulant activities (cancer procoagulant and tissue factor). Decreased levels of inhibitors of coagulation, impaired fibrinolysis, the presence of antiphospholipid antibodies and an acquired activated protein C resistance contribute to the hypercoagulable state. The activation of coagulation is also implicated in tumor proliferation through interactions of coagulation with inflammation and increased tissue factor pathway inhibitor. Laboratory diagnosis of the thrombophilic state include (1) elevation of clotting factors, fibrinogen/fibrin degradation products, hyperfibrinogenemia and thrombocytosis and (2) elevation of specific markers of activation of coagulation: fibrinopeptide A, fragment 1 + 2, thrombin-antithrombin complexes and D-dimers. However, none of the tests has any predictive value for the occurrence of thrombotic events in one individual patient. In patients with venous thromboembolism a noninvasive screening for occult cancer is able to detect a relatively high incidence of hidden cancer and the search for thrombophilia seems important in patients without known cancer.
血栓形成和弥散性血管内凝血是癌症常见的并发症。与癌症相关的特定情况，如因制动或血流阻塞导致的血流淤滞、手术、感染、化疗药物引起的内皮损伤以及凝血异常，都会导致癌症患者出现高凝和易栓状态。癌症患者的这种促凝状态主要源于肿瘤细胞表达和释放促凝活性物质（癌促凝物质和组织因子）的能力。凝血抑制剂水平降低、纤维蛋白溶解功能受损、抗磷脂抗体的存在以及获得性活化蛋白C抵抗都促成了高凝状态。凝血的激活还通过凝血与炎症的相互作用以及组织因子途径抑制剂的增加而与肿瘤增殖有关。易栓状态的实验室诊断包括：（1）凝血因子、纤维蛋白原/纤维蛋白降解产物升高，纤维蛋白原血症和血小板增多；（2）凝血激活的特异性标志物升高：纤维肽A、片段1 + 2、凝血酶 - 抗凝血酶复合物和D - 二聚体。然而，这些检查对于单个患者血栓事件的发生均无预测价值。在静脉血栓栓塞患者中，对隐匿性癌症进行无创筛查能够检测出相对较高的隐匿性癌症发病率，而在无已知癌症的患者中寻找易栓倾向似乎很重要。
