Background: This study set out to evaluate, in patients with gemcitabine-resistant pancreatic cancer, the response rate and toxicity of S-1 plus cisplatin (CDDP).
Methods: Seventeen patients with histologically diagnosed invasive ductal pancreatic cancer were enrolled in this study. All patients had growing recurrent pancreas cancer despite the administration of gemcitabine. Thirteen patients underwent pancreatectomy, and 2 underwent choledochojejunostomy and gastrojejunostomy without pancreatectomy. S-1 (80 mg/m(2) per day) was orally administered for 21 consecutive days, followed by a 14-day rest period. CDDP (40 mg/m(2)) in 500 ml saline was administered by intravenous drip on day 8. This schedule was repeated every 5 weeks until the occurrence of disease progression, unacceptable toxicities, or the patient's refusal to continue.
Results: Five (29.4%) patients achieved a partial response and 2 (11.8%) had stable disease. In 5 of 15 patients (33.3%) who had elevated serum carbohydrate antigen (CA)19-9 levels at the start of treatment the CA19-9 was reduced by more than 50%. The median survival time was 10 months (range, 20 months), with 63.7% and 31.9% of patients alive at 6 and 12 months, respectively. Major adverse reactions in the 15 patients included gastrointestinal toxicities of grade 1 or 2. Only one patient (5.9%) developed grade 3 leucopenia.
Conclusion: S-1 with CDDP has a promising effect against gemcitabine-resistant pancreatic cancer, with easily manageable toxicities. Further investigation of this regimen is warranted in patients with pancreatic cancer, especially in comparison with gemcitabine.