Primary results of multicenter phase II study of neoadjuvant chemotherapy with S-1 and oxaliplatin for locally advanced gastric cancer (Neo G-SOX PII)

Date 29 September 2019
Event ESMO 2019 Congress
Session Poster Display session 2
Topics Gastric Cancer
Presenter Akira Miki
Citation Annals of Oncology (2019) 30 (suppl_5): v253-v324. 10.1093/annonc/mdz247
Authors A. Miki1, H. Satake2, T. Watanabe3, N. Tanaka4, K. Hirata5, K. Shimozaki5, H. Tanioka6, M. Matsuura7, T. Kyogoku7, M. Tatsumi8, K. Matoba9, Y. Oka10, S. Adachi10, H. Yasui11, M. Kotaka12, T. Kato13, A. Tsuji14
  • 1Surgery, Toyooka Hospital, 668-8501 - Toyooka/JP
  • 2Medical Oncology, Kansai Medical University, 573-1191 - Hirakata/JP
  • 3Department Of Surgery, Red Cross Society Himeji Hospital, Himeji/JP
  • 4Department Of General And Gastroenterological Surgery, Kagawa Prefectural Central Hospital, Takamatsu/JP
  • 5Division Of Gastroenterology And Hepatology, Department Of Internal Medicine, Keio University School of Medicine, 160-0016 - Tokyo/JP
  • 6Clinical Oncology, Kawasaki Medical School Hospital, 701-0192 - Kurashiki/JP
  • 7Department Of Surgery, Kobe City Nishi-Kobe Medical Center, Kobe/JP
  • 8Department Of Surgery, Hoshigaoka Koseinenkin Hospital, Hirakata/JP
  • 9Department Of Gastroenterology, Kobe Rosai Hospital, Kobe/JP
  • 10Department Of Surgery, Nishinomiya munincipal central hospital, Nishinomiya/JP
  • 11Medical Oncology, Kobe City Medical Center General Hospital, 650-0047 - Kobe/JP
  • 12Surgery, Sano Hospital-Gastrointestinal Cancer Centre, 655-0031 - Kobe/JP
  • 13Department Of Surgery, Osaka National Hospital, 5400006 - Osaka/JP
  • 14Clinical Oncology, Kagawa University Faculty of Medicine/Graduate School of Medicine, 761-0793 - Miki/JP



Prognosis for locally advanced gastric cancer (LAGC), such as clinical T4 disease, bulky nodal metastases, type 4 and large type 3 gastric cancer, was not satisfactory even by D2 gastrectomy followed by adjuvant chemotherapy. Neoadjuvant chemotherapy is another promising approach. We conducted a multi-institutional, single-arm, open label, phase II study (Clinical trial information: UMIN000018661). The aim of this study was to evaluate the efficacy and safety of the neoadjuvant chemotherapy of G-SOX followed by gastrectomy with D2/3 lymph node dissection for LAGC.


Eligibility criteria included histologically proven adenocarcinoma of the stomach; clinical T4; clinically resectable gastric cancer of type 4 or large type 3 (over 8 cm); bulky nodal metastases around major branched arteries to the stomach; resectable peritoneal dissemination (pathological CY1 or P1, except for clinical CY1 or P1). Patients received two cycles of neoadjuvant chemotherapy with S-1 (80 mg/m2, p.o., days 1-14 followed by 1 week rest) and oxaliplatin (130 mg/m2 at day 1), followed by D2 or higher surgery with no residual disease. Patients with pathological R0/1 resection received S-1 (80 mg/m2, p.o., days 1-28 followed by 2 week rest) for 1 year as adjuvant chemotherapy. Primary endpoint was curative resection rate.


Forty-one patients were enrolled from 11 institutions. Of the patients, 39 patients (95%) completed the two courses of neoadjuvant chemotherapy of G-SOX, 37 (90%) received gastrectomy, and 36 (87.8%) received curative resection (R0/1). Pathological response rate after neoadjuvant chemotherapy of G-SOX was 40.5%. Most frequent drug-related adverse events during neoadjuvant chemotherapy of G-SOX were anemia (76%), neutropenia (66%), anorexia (63%) and peripheral sensory neuropathy (63%). No treatment related deaths were observed.


Neoadjuvant chemotherapy of G-SOX is a feasible and one of the promising strategies for patients with LAGC.

Clinical trial identification


Editorial acknowledgement

Legal entity responsible for the study

The authors.


Has not received any funding.


H. Satake: Honoraria (self): Taiho; Honoraria (self): Yakult. M. Kotaka: Honoraria (self): Taiho; Honoraria (self): Yakult. T. Kato: Honoraria (self): Taiho; Honoraria (self): Yakult. A. Tsuji: Honoraria (self): Taiho; Honoraria (self): Yakult. All other authors have declared no conflicts of interest.