15679 Background: We analyzed two phase II studies of paclitaxel- or docetaxel-based regimens combined with the same dose and schedule of 5-fluorouracil (5-FU) and leucovorin (LV) in advanced gastric cancer. Methods: Patients with advanced gastric adenocarcinoma, a performance status ≤ 2, and adequate organ functions received paclitaxel 175 mg/m2 (FLTaxol) or docetaxel 75 mg/m2 (FLTaxotere) on day 1 followed by a leucovorin bolus 20 mg/m2 (day 1–3) and a 24-hour infusion of 5-FU 1,000 mg/m2 (day 1–3) every 3 weeks. Prophylactic granulocyte colony-stimulating factor (G-CSF) was administered for FLTaxotere from day 4 to 8. On the other hand G-CSF was administered therapeutically for FLTaxol when absolute neutrophil count was ≤ 500/μL. Treatments were continued until disease progression, unacceptable toxicity, or patient's withdrawal. Results: 60 patients were enrolled in FLTaxol study (37 first-line + 23 second-line) and 66 patients were enrolled in FLTaxotere study (38 first-line + 28 second-line). Overall response rate were comparable between two treatment groups (paclitaxel, 31.6%; docetaxel, 25.7%). With the median follow-up period of 10 months for FLTaxol and 8 months for FLTaxotere, the time-to-progression were 3.1 months (95% C.I., 1.21 - 4.99 months) for FLTaxol and 5.0 months (95% C.I., 3.51 - 6.49 months) for FLTaxotere (P=0.31). Overall survival were also comparable; 10.5 months (95% C.I., 5.73 - 15.27 months) for FLTaxol and 8.4 months (95% C.I., 5.22 - 11.5 months) for FLTaxotere (P=0.20). The most frequent grade 4 adverse event was neutropenia for both (FLTaxol, 36.7%; FLTaxotere, 56.1%). The febrile neutropenia were observed in 11.6% of FLTaxotere treated patients vs. 3.3 % of FLTaxol treated patients. One patient died from septic shock during the first cycle of FLTaxotere treatment. There was no treatment related death during the FLTaxol treatment. Conclusions: The two taxanes are equally active in advanced gastric cancer. Despite the prophylactic use of G-CSF in FLTaxotere treated patients, neutropenia was more frequent and severe in FLTaxotere regimen. No significant financial relationships to disclose.