Phase II Trial of Gemcitabine and S-1 for Patients with Advanced Pancreatic Cancer

Purpose: To evaluate the efficacy and safety of combined gemcitabine and S-1 as first-line chemotherapy for patients with locally advanced or metastatic pancreatic cancer.

Methods: This study included patients who had been diagnosed with unresectable, locally advanced or metastatic adenocarcinoma arising from the pancreas, which was histologically or cytologically confirmed and involved at least 1 unidimensionally measurable lesion. The regimen consisted of intravenous 1,000 mg/m(2) gemcitabine on day 1 and 8 combined with oral S-1 on days 1-14 every 21 days. The dosage of S-1 was based on the body surface area (BSA) as follows: 40 mg bid (total 80 mg/day) for a BSA of <1.25, 50 mg bid (total 100 mg/day) for a BSA of ≥1.25 but <1.5, and 60 mg bid (total 120 mg/day) for a BSA of ≥1.5. Treatment consisted of at least 2 courses unless rapid disease progression was noted. The primary end points were the response and disease control rates, and the secondary end points were toxicity and survival.

Results: Thirty-seven patients were enrolled between August 2005 and December 2010. The median number of chemotherapy cycles was 4 (range 1-28 cycles). Response to treatment could be evaluated in 31 patients. None of the patients showed complete response, but 5 achieved partial response. The response rate was thus 13.5 % [95 % confidence interval (CI) 2.7-24.3 %] in the intent-to-treat population. Sixteen patients (43.2 %; 95 % CI 27-59.5 %) showed stable disease, and the overall disease control rate was 56.8 % (95 % CI 40.6-72.9 %). For all 37 patients, the median progression-free survival was 4.6 months (95 % CI 1.8-7.6 month), and the median overall survival was 9.4 month (95 % CI 5.8-12.6 month). Chemotherapy-related grade 3/4 hematological toxicities were neutropenia (36.1 %), leucopenia (22.2 %), and anemia (13.9 %). The non-hematological toxicities were generally mild.

Conclusions: Combination chemotherapy with gemcitabine and S-1 was effective, convenient, and safe in patients with advanced pancreatic cancer.