A phase II study of preoperative chemotherapy with docetaxel, cisplatin, and S-1 followed by gastrectomy with D2 plus para-aortic lymph node dissection for gastric cancer with extensive lymph node metastasis: JCOG1002.

Background: Gastric cancer with extensive lymph node metastasis is commonly considered unresectable, with a poor prognosis. We previously reported the results of the use of cisplatin and S-1 as preoperative chemotherapy for gastric cancer with extensive lymph node metastasis; docetaxel, cisplatin, and S-1 (DCS) have now been investigated for the same purpose.
Methods: Patients received two or three 28-day cycles of DCS therapy (docetaxel at 40 mg/m ² and cisplatin at 60 mg/m ² on day 1, S-1 at 40 mg/m ² twice daily for 2 weeks) followed by gastrectomy with D2 plus para-aortic nodal dissection. After R0 resection, S-1 chemotherapy was given for 1 year. The primary end point was the response rate (RR) to preoperative chemotherapy determined by central peer review according to the Response Evaluation Criteria in Solid Tumors version 1.0. The planned sample size was 50, with one-sided alpha of 10 %, power of 80 %, expected RR of 80 %, and threshold of 65 %.
Results: Between July 2011 and May 2013, 53 patients were enrolled, of whom 52 were eligible. The clinical RR was 57.7 % [30/52, 80 % confidence interval 47.9-67.1 %, p = 0.89], and R0 resection was achieved in 84.6 % of patients (44/52). Common grade 3 or grade 4 adverse events during DCS therapy were leukocytopenia (18.9 %), neutropenia (39.6 %), and hyponatremia (15.1 %). The common grade 3 or grade 4 surgical morbidity was abdominal infection (10.2 %). The pathological RR was 50.0 % (26/52).
Conclusions: Preoperative DCS therapy was feasible but did not show a sufficient RR. Preoperative cisplatin and S-1 therapy is still considered the tentative standard treatment for this population until survival results are known.