Fibrinolytic profiles in patients with small cell carcinoma of the lung

1. Elevated levels of fibrinogen were observed in 100% of untreated patients with SCCL. The elevated fibrinogen tended to normalize with complete remission in response to combination chemotherapy. 2. FDPs were increased in 33% of patients in the limited disease group and in 37% in the extensive disease group. Elevated levels of D-dimers were seen in 26% in the limited disease group and in 50% in the extensive disease group. Levels of FDPs did not parallel levels of D-dimers. Some cases of very advanced disease showed increases in both FDPs and D-dimers. 3. When FDPs were within normal limits, D-dimers tended to be elevated. 4. Levels of plasminogen, alpha 2-antiplasmin, and plasmin were and remained within normal limits throughout the course of treatment, while concentrations of FDPs and D-dimers increased. 5. Plasminogen, alpha 2-antiplasmin, plasmin, FDPs and D-dimers did not show any trend. 6. Peripheral blood measurements did not reflect the crucial role of plasmin in modulating blood fibrinolysis and the metastatic cascade. 7. Evidence of the action of the fibrinolytic system at tumor sites failed to correlate with results of laboratory tests.