Thrombosis-inducing activity found in plasma from two patients with advanced lung cancer.

In 2 patients with lung cancer, the coagulation system was supposed to be activated by the findings of elevation of plasma fibrinogen, fibrinogen degradation product (FDP) and/or peripheral platelet counts. The plasma thromboxane B2 and 6-keto-prostaglandin F1 alpha levels in 1 patient were measured and proved to be 160 and 20 times higher than the control level, respectively. When 0.5 ml of plasma from each patient was given intravenously into Balb/c mice, the mice died within 5 min. The multiple thrombosis mainly composed of aggregated platelets and present in the lungs of these mice probably led to death of these animals. On the contrary, no such activity was found in plasma from healthy subjects or other patients with lung cancer who showed no manifestations of enhancement in the coagulation system.