Phase II study of irinotecan plus cisplatin with concurrent radiotherapy for the patients with limited-disease small-cell lung cancer

Background: A recently conducted randomized, phase III study that compared irinotecan plus cisplatin (IP) with etoposide plus cisplatin for the patients with extensive disease SCLC revealed a superior median survival rate and a superior 2-year survival rate for the IP combination therapy. Yet there have been few such reports on the patients suffering with limited disease SCLC (LD-SCLC). We conducted a phase II trial to evaluate the efficacy and toxicity of administering IP with concurrent radiotherapy for the patients with LD-SCLC. Patients and Methods: Twenty chemotherapy-naïve patients with LD-SCLC were enrolled in our study. The patients were treated with 40 mg/m² irinotecan on days 1, 8 and 15 and with 60 mg/m² cisplatin on day 1 every 4 weeks until a maximum of six cycles was delivered. Once-daily radiotherapy included the administration of 50.4 Gy in 28 fractions. After completion of the radiation therapy, the dose of irinotecan was increased to 60 mg/m². Results: The response rate was 85% (CR: 6; partial response, PR: 11). The median survival was 20.0 months (95% CI: 15.6-24.4 months) with 1-year and 2-year overall survival rates of 85 and 35%, respectively. The median progression free survival (PFS) was 12 months (95% CI: 6.2-18.1 months) with a 1-year PFS of 36%. The major hematologic toxicities of this regimen were neutropenia (60%), leukopenia (55%), anemia (20%) and thrombocytopenia (10%). The non-hematologic toxicities were nausea/vomiting (55%), diarrhea (35%) and dysphagia (15%). Conclusions: Our data show that IP with concurrent radiotherapy is an effective and tolerable regimen for the treatment of LD-SCLC and these findings warrant further investigation.