682P - A Multicenter Phase II Study of Neoadjuvant Chemotherapy (NAC) Combined with Docetaxel, Cisplatin and S-1 (DCS) for Locally advanced Gastric Cancer (AGC)

Abstract

ABSTRACT Background We have previously reported the recommended dose of preoperative combination chemotherapy with intravenous administration of docetaxel and cisplatin (35mg/m2 on days 1 and 15), and oral S-1 (40mg/m2 twice daily on days 1-14) in the phase I study. This regimen also provided surprisingly high pathological responses in 12 pts. Therefore, we conducted a multicenter phase II trial to evaluate efficacy and safety of divided DCS therapy for patients (pts) with locally AGC. Methods The study included pts with histological confirmation of gastric cancer, no prior chemotherapy, adequate organ function, ECOG PS 0-1, age 20-75, clinical T3-4, cM0 and CY0 (Japanese Classification), and documented informed consent. This treatment was conducted 2 courses every 4 weeks followed by standard D2 surgery within 8 weeks. The primary endpoint was histological response and secondary endpoints included clinical response, R0 resectability, surgery related morbidity, adverse events and overall survival. Results From July 2009 to June 2011, 56 pts (median age 63.5, male/female 43/13, PS0/1 50/6) were enrolled and received DCS therapy. But 8 pts stopped chemotherapy after one course (6 of them proceeded surgery but 2 pts refused treatment). Forty eight pts completed 2 courses of chemotherapy. Therefore, 54 pts were evaluable response to chemotherapy and pathological analysis. The histological response rate was 74.1% in primary tumor with grade 1b; 10 lesions, grade 2; 24 lesions and grade3; 6 lesions, and 70.2% in lymph node with grade 1b; 9 cases, grade 2; 10 cases and grade 3; 14 cases, respectively. Surgery related morbidity was 13.0% and R0 resection rate was 98.1% (53/54). Grade 3/4 adverse events were acceptable such as leucopenia (8.9%), neutropenia (17.9%), febrile neutropenia (7.1%), anorexia (10.7%), and diarrhea (8.9%). There was no treatment related death and no major surgical complications except for one. Conclusions Neoadjuvant DCS chemotherapy demonstrated a high histological response rate, acceptable feasibility and a sufficient R0 resection rate. This divided DCS regimen is attractive as NAC for pts with locally AGC. Disclosure All authors have declared no conflicts of interest.