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/m2 and irinotecan 80 mg/m2 intravenously (i.v.) on days 1 and 8 followed by two 21-day cycles of cisplatin 60 mg/m2 i.v. on days 43 and 64, and etoposide 100 mg/m2 i.v. 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.