Esophageal cancer is a highly aggressive malignancy with a poor overall outcome.

The purpose of this study is to evaluate the progression free survival and safety of irinotecan plus S1 versus S1 alone in the patients with previously treated advanced esophageal cancer

Two arms, phase 3 study of irinotecan plus S1 versus S1 alone in previously treated patients with recurrent or metastatic esophageal cancer. 240 Patients will be enrolled in this trial. The primary objective of this study is to determine the PFS of the two arms. One arm is as follows: irinotecan 160 mg/m2 will be administered as an intravenous infusion over 60 minutes on Days 1, followed by S1 80mg to 120 mg per day on Days 1-10, every 14 days per cycle. The other arm is S1 80mg to 120 mg per day on Days 1-14, every 21 days per cycle.This study will also include the investigation of UGT1A1polymorphisms in the study population.

Inclusion Criteria:

• Histologically proven esophageal squamous cell carcinoma;
• 18 ≤ age ≤ 70;
• ECOG 0-2;
• Previously Treated with platinum or paclitaxel based regimen;
• Uni-dimensionally measurable disease (CT or MRI as per RECIST);
• Patients should have a projected life expectancy of at least 3 months;
• Completion of baseline quality of life questionnaire
• Adequate bone marrow functions (ANC ≥ 1,500/ul, blood platelet ≥ 100,000/ul, haemoglobin ≥ 10g/dl);
• Adequate renal functions(serum creatinine ≤ 1.5mg/dl)
• liver functions (serum bilirubin ≤ 1.5UNL, AST/ALT ≤ 3 times(normal value)
• Written informed consent

Exclusion Criteria:

• Previous chemotherapy with 5-FU or irinotecan after recurrence or metastasis;
• adjuvant chemotherapy with 5-FU-based chemotherapy within 6 months prior to the start of study treatment;
• Active infection requiring antibiotics
• Pregnant, lactating women
• Psychiatric illness, epileptic disorders
• Concurrent systemic illness not appropriate for chemotherapy
• History of other malignancy within 5 years except for non-melanoma skin cancer, cervix in situ carcinoma