Short-term outcomes of a phase II trial of perioperative capecitabine plus oxaliplatin therapy for advanced gastric cancer with extensive lymph node metastases (OGSG1701).

Background: The prognosis of advanced gastric cancer (GC) with extensive lymph node (LN) metastasis treated with surgery alone remains poor. We conducted a multicenter phase II study to evaluate the efficacy and safety of perioperative capecitabine plus oxaliplatin (CapeOx) therapy in patients with advanced GC with extensive LN metastases.

Patients and methods: Patients with histologically proven HER2-negative or unknown gastric adenocarcinoma with paraaortic LN (PALN) metastases and/or bulky LN metastases located at the celiac axis, common hepatic artery, and/or splenic artery were included in the study. Patients received three cycles of preoperative CapeOx every 3 weeks, followed by five cycles of postoperative CapeOx after gastrectomy with D2 or D2 + including PALN dissection. The primary endpoint was the response rate (RR) according to the RECIST v1.0 criteria.

Results: Thirty patients from 14 institutions were enrolled from September 2017 to June 2022. Complete response, partial response, stable disease, and progressive disease occurred in zero, 20, eight, and one patient, respectively. One patient was not evaluated. The RR was 66.7% (90% confidence interval, 50.1-80.7%; one-sided P = 0.049). The preoperative chemotherapy completion rate and the curative resection rate were 96.7% and 93.3%, respectively. The minor (grade ≥ 1b) pathological RR was 66.7%. Grade 3 adverse events of preoperative chemotherapy included neutropenia in 3.3%, anemia in 6.7%, and anorexia in 10.0%. One treatment-related death occurred due to postoperative complications.

Conclusion: Preoperative CapeOx chemotherapy showed a favorable RR, curative resection rate, and acceptable adverse events in patients with advanced GC with extensive LN metastasis.

Registration number: UMIN000028749 and jRCTs051180186.