Biweekly gemcitabine with S-1 combination chemotherapy in locally advanced or metastatic pancreatic cancer

Objective: Gemcitabine (GEM)-based combination chemotherapy has been studied to determine whether or not it improves outcomes, but results have generally been disappointing. We retrospectively compared chemotherapy with biweekly GEM plus a novel form of an oral 5-fluorouracil derivative (S1) (GEM+S-1) with GEM alone in locally advanced or metastatic pancreatic cancer. Patients and Methods: We studied patients with a histologically or cytologically confirmed diagnosis of locally advanced or metastatic pancreatic cancer with measurable lesions. Ninety-six patients received GEM+S-1 (GEM 800-1,000 mg/m intravenously on days 1 and 15 plus S-1 40 mg/m twice daily orally on days 1-7 and days 15-21 of a 28-day cycle), and 66 patients received GEM alone (GEM alone, 1,000 mg/m intravenously on days 1, 8, and 15 of a 28-day cycle). Treatment was repeated every 4 weeks. Results: The overall response rate was 36.5% in the GEM+S-1 group and 7.6% in the GEM-alone group (P = 0.0028). The median survival time was 16.2 months in the GEM+S-1 group and 7.8 months in the GEM-alone group (P = 0.008). Conclusions: This regimen for GEM+S-1 combination chemotherapy is feasible, well tolerated, and more effective than GEM alone in patients with locally advanced or metastatic pancreatic cancer.