Phase II Study of Irinotecan Plus Cisplatin Induction Followed by Concurrent Twice-Daily Thoracic Irradiation With Etoposide Plus Cisplatin Chemotherapy for Limited-Disease Small-Cell Lung Cancer

Purpose Irinotecan plus cisplatin (IP) chemotherapy demonstrated a promising outcome with a high complete response (CR) rate in chemotherapy-naïve patients with extensive small-cell lung cancer (SCLC). We evaluated the efficacy of induction IP chemotherapy followed by concurrent etoposide plus cisplatin (EP) chemotherapy with twice-daily thoracic radiotherapy (TDTRT) in limited-disease SCLC (LD-SCLC). Patients and Methods Between November 2001 and May 2003, 35 chemotherapy-naïve patients with LD-SCLC were enrolled. Thirty-three patients (94%) were male, and 29 (83%) had an Eastern Cooperative Oncology Group performance status of 0 or 1. The median age was 63 years. Treatment consisted of two 21-day cycles of cisplatin 40 mg/m 2 and irinotecan 80 mg/m 2 intravenously (IV) on days 1 and 8 followed by two 21-day cycles of cisplatin 60 mg/m 2 IV on days 43 and 64, and etoposide 100 mg/m 2 IV on days 43 to 45 and 64 to 66, with concurrent TDTRT of total 45 Gy beginning on day 43. Results All 35 patients were assessable for response. The objective response rate was 97% (CR, 3; partial response [PR], 31) after induction chemotherapy and 100% (CR, 15; PR, 20) after concurrent chemoradiotherapy (CCRT). After a median follow-up of 26.5 months, the median survival was 25.0 months (95% CI, 19.0 to 30.9) with 1- and 2-year overall survival rates of 85.7% and 53.9%, respectively. Median progression-free survival (PFS) was 12.9 months with a 1- and 2-year PFS of 58.5% and 36.1%, respectively. The most common toxicities were grade 3 or 4 neutropenia in 68% of patients during induction chemotherapy and 100% during CCRT. Febrile neutropenia occurred in 20% of patients during induction chemotherapy and 60% during CCRT. Conclusion IP induction chemotherapy followed by concurrent TDTRT with EP chemotherapy showed a promising activity with favorable 1- and 2-year survival rates. Based on the favorable outcome in this trial, this regimen should be evaluated in a large phase III trial.