[Platelet activation in lung cancer]

During primary hemostasis the platelets aggregate to form the platelet thrombus. ADP and thrombin generated by coagulation are the main agonists in platelet aggregation. In a previous study we were able to show that patients with lung cancer had hypercoagulability, hyperfibrinogemia (≥ 6.22 g/L) was predictive of thromboembolic disease at the start of diagnosis before any therapy. In this study, we studied platelet aggregation in these patients in order to demonstrate whether they have hyperaggregability associated with the hypercoagulability demonstrated previously, and this by evaluating abnormalities in primary hemostasis (platelet count and platelet aggregation). One hundred and one patients diagnosed before any therapy and 72 blood donors were included. Agonists used for platelet aggregation are collagen and adenosine diphosphate at low concentrations. Hyperaggregability is observed when blood platelets are stimulated by ADP at different concentrations (p ≤ 0.01). This hyperaggregability is influenced by the histological type and not the development of the cancer, the age of the subjects and the platelet count, it is independent of hyperfibrinogemia and the occurrence of thromboembolic disease. However, an increase in the platelet level is found in patients with hyperfibrinogemia. Patients with lung cancer present platelet activation observed by aggregometry in response to ADP; which is not influenced by hyperfibrinogemia during cancer.