Patients with untreated extensive-stage small cell lung cancer(SCLC) were randomly assigned to receive either irinotecan/cisplatin (IP) or etoposide/cisplatin(EP), The association of efficacy and toxicity of IP regimen was analyzed.

This is a randomized, multicenter study. Patients are randomized to irinotecan/cisplatin (IP) or etoposide/cisplatin (EP) treatment arms. The IP regimen consisted of at most 6 cycles of irinotecan 65 mg/m2 of body-surface area on days 1, 8 and cisplatin 75mg/m2 of body-surface area on day 1. The EP regimen consisted of at most 6 cycles of etoposide 100 mg/m2 of body-surface area from day 1 to 3 and cisplatin 75mg/m2 of body-surface area on day 1. Cycle length for the two arms was 3 weeks. The dose adjustment was allowed in at most within ±5% per investigator discretion if necessary.

Inclusion Criteria:

• Eastern Cooperative Oncology Group (ECOG) of 0 to 2
• A life expectancy of at least 3 months
• Measurable lesions
• Adequate hematologic function

Exclusion Criteria:

• Infection
• Myocardial infarction within the preceding three months
• Symptomatic brain metastases or receiving radiotherapy less than 4 weeks
• Pregnancy or breast-feeding