A phase II study of gemcitabine/nab-paclitaxel/S-1 combination neoadjuvant chemotherapy for patients with borderline resectable pancreatic cancer with arterial contact

The prognosis of patients with borderline resectable pancreatic cancer with arterial contact (BRPC-A) is extremely poor, and effective preoperative treatment is indispensable. We evaluated the clinical efficacy and safety of neoadjuvant chemotherapy, including gemcitabine, nab-paclitaxel and S-1 (GAS), for patients with BRPC-A.A multicentre, single-arm, phase II study was performed. Patients were administered 1000 mg/m2 gemcitabine on day 1, 125 mg/m2 nab-paclitaxel on day 1 and 60-100 mg/day S-1 on days 1-7 during a 14-day cycle. Patients were then assessed for resectability and response to treatment after six cycles. The primary end-points were 2-year overall survival (OS) rate and median OS time (trial registration: jRCTs061180045, UMIN000016630).Forty-seven patients with BRPC-A were eligible for the present study. Six courses of neoadjuvant GAS regimen were completed in all eligible patients. The rate of grade III/IV toxicities occurred in 14 (30%) patients during the neoadjuvant GAS regimen. The response and disease control rates were 43% and 96%, respectively. Forty-five (96%) patients received potentially curative pancreatectomy, whereas two did not owing to disease progression. R0 resection was performed in 40 (86%) of 47 eligible patients. Eleven (24%) patients experienced postoperative major complications (>grade III), including one mortality. The 2-year OS rate and median OS time among 47 eligible patients were 70.1% and 41.0 months, respectively.The neoadjuvant GAS chemotherapy regimen for BRPC-A showed good efficacy with mild toxicity, resulting in a high R0 resection rate and prolonged survival in patients with BRPC-A.