Irinotecan plus cisplatin chemotherapy followed by concurrent thoracic irradiation with low-dose weekly cisplatin for limited-disease small-cell lung cancer

Abstract

A phase II trial of irinotecan and cisplatin (IP) as induction chemotherapy followed by conventional thoracic irradiation concurrent with low-dose weekly cisplatin for limited-disease small-cell lung cancer (LDS-SCLC). Between February 2005 and December 2008, 34 chemotherapy-naïve patients with LD-SCLC were enrolled. 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 conventional thoracic irradiation at a dose of 54 Gy concurrent with cisplatin at dose of 20 mg/m(2) weekly then prophylactic cranial irradiation at dose of 30 Gy in 10 fractions for those achieved complete or partial response. Only 33 patients received the treatment protocol, and they were assessed for response and toxicity. After induction chemotherapy, overall response rate was (72.73%). After median follow-up of 27 months, the median survival was 25 months (95% CI, 21.249-28.751) with 1 and 2-year overall survival rates of 83 and 55%, respectively. Median progression-free survival (PFS) was 15 months (95% CI, 10.311-19.689) with a 1- and 2-year PFS of 59 and 38%, respectively. The most common toxicities during induction chemotherapy were neutropenia (81%), thrombocytopenia (69%), and diarrhea (63%) while esophagitis (84%) and pneumonitis (30%) were the most common toxicities during concurrent chemo-radiation. Relapse rate was 61% with distant metastasis in 42% and local recurrence in 26%. This protocol of induction irinotecon-based regimen followed by delayed concurrent thoracic irradiation with low-dose weekly cisplatin is effective with acceptable toxicities. Based on the favorable outcome in this trial, this regimen should be evaluated in a large phase III trial.