[Coagulation and bronchopulmonary cancers: from clinical aspects to biology].

Activation of coagulation and of the fibrinolytic system has been identified in small cell and non-small cell cancers respectively. For the clinician this poses the diagnostic problem of a thrombosis, which is most often venous with or without pulmonary emboli, complicating the evolution of an already diagnosed cancer. The inverse is that these features may reveal an underlying neoplasm and amongst the most common of these would be bronchopulmonary cancer. Numerous laboratory studies have shown the existence of a state of hyper-coagulability, with disseminated intra-vascular coagulation, which is more or less compensated and is the more marked, the more advanced the cancer is. One should not fail to recognise that this state of hyper-coagulability may be aggravated by certain cytotoxic drugs. At the level of the tumour itself, there seems to be interactions between the cancer cells and the coagulation and fibrinolytic system: these interactions are very different according to the histological type as to whether they are small cell or non-small cell bronchopulmonary cancers.