Survival results of a randomised two-by-two factorial phase II trial comparing neoadjuvant chemotherapy with two and four courses of S-1 plus cisplatin (SC) and paclitaxel plus cisplatin (PC) followed by D2 gastrectomy for resectable advanced gastric cancer

Abstract

Background: The prognosis for stage III gastric cancer is unsatisfactory by D2 gastrectomy and S-1 adjuvant chemotherapy. Both S-1 plus cisplatin (SC) and paclitaxel plus cisplatin (PC) are promising regimens as neoadjuvant chemotherapy; however, the optimal duration remains unclear.

Patients and methods: In this 2×2 randomised phase II trial, stage III gastric cancer patients, those with a prognosis corresponding to stage III, and macroscopically resectable stage IV cases were randomised to two or four courses of S-1 (80 mg/m(2) for 21 d with 1 week rest)/cisplatin (60 mg/m(2) at day 8) or PC (80 and 25 mg/m(2), respectively, on days 1, 8, and 15 with 1 week rest) as neoadjuvant chemotherapy. The primary end-point was the 3-year overall survival (OS).

Results: Between October 2009 and July 2011, 83 patients received 2 courses of SC (n=21), 4 courses of SC (n=20), 2 courses of PC (n=21) and 4 courses of PC (n=21). The 3-year OS was 60.9% for SC and 64.3% for PC and 64.3% for the two courses and 61.0% for the four courses. Subset analyses demonstrated no subgroup which showed any potential survival benefit by PC in comparison to SC or by four courses as in comparison to two courses.

Conclusions: Two courses of SC as neoadjuvant chemotherapy are recommended as a test arm of a future phase III study for patients with locally advanced gastric cancer.

Clinical trial number: UMIN-000002595.

Keywords: Gastric cancer; chemotherapy; duration; neoadjuvant; surgery; survival.