Urokinase combination chemotherapy in small cell lung cancer. A phase II study

Fifty-one patients with small cell lung cancer (SCLC) were treated with alternating urokinase (UK)-cyclophosphamide-doxorubicin (Adriamycin, Adria Laboratories, Columbus, OH)-vincristine and cisplatin-etoposide-vincristine. UK was given as a loading dose of 3000 micrograms/kg body weight, followed by 3000 micrograms/kg/h for 6 hours. Thoracic irradiation with split technique (46 Gy) and prophylactic cranial irradiation (25 Gy) were administered to responding patients. A second staging was performed in patients exhibiting a clinical complete response (CR) after 1 year.

In 27 patients with limited disease, there were 23 CR and 8 partial responses (PR) (CR, 85.1%; 66.2-95.8% at 95% confidence intervals); in 24 patients with extensive disease, there were 17 CR, 4 PR, and 3 cases with progression. Pathologically proven CR were observed in 59.2% patients with limited disease and 33.3% patients with extensive disease. Survival rates were as follows: in patients with limited disease, 1 year, 85.1%; 2 years, 55.5%; and 3 years, 25.9%; in patients with extensive disease, 1 year, 54.1; and 2 years, 16.9%. Median survival times were 26.3 months (patients with limited disease) and 13.3 months (patients with extensive disease). UK-related toxic effects included four episodes of mild to moderate bleeding, one allergic reaction, and one cerebrovascular accident. Myelotoxicity was severe, with a median of two episodes of Grade III-IV (World Health Organization classification) aplasia per patient.

These results are consistent with a potential benefit of fibrinolytic therapy in combination with chemotherapy in patients with SCLC with limited disease. Additional trials are indicated.