Three-year and five-year outcomes of a phase II study of perioperative CapeOx therapy for advanced gastric cancer with extensive lymph node metastasis (OGSG1701).

Abstract

387 Background: The prognosis of advanced gastric cancer (AGC) with para-aortic and/or bulky lymph node metastases remains poor. The OGSG1701 phase II study previously demonstrated favorable feasibility and short-term efficacy of perioperative capecitabine plus oxaliplatin (CapeOx) therapy ( Y. Kimura, et al. Gastric Cancer 2024 ). Here, we report updated long-term survival outcomes. Methods: This was a multicenter, single-arm phase II trial in patients with HER2-negative or unknown AGC involving No.16a2/16b1 para-aortic and/or bulky nodal metastases. Patients received three cycles of neoadjuvant CapeOx (capecitabine 2000 mg/m² days 1–14, oxaliplatin 130 mg/m² day 1, every 3 weeks), followed by gastrectomy with D2 ± para-aortic lymphadenectomy, and five cycles of adjuvant CapeOx. Overall survival (OS) and progression-free survival (PFS) were evaluated as secondary endpoints using the Kaplan–Meier method. Results: Thirty patients were enrolled between 2017 and 2022. The 3- and 5-year OS rates were 79.0% (95% CI, 59.0–90.0%) and 61.0% (95% CI, 38.9–77.1%), respectively; the median OS was 64.9 months (95% CI, 41.2–not estimable). The 3-year PFS rate was 46.7% (95% CI, 28.4–63.0%), and the median PFS was 29.0 months (95% CI, 9.4–not estimable). No new treatment-related deaths occurred during long-term follow-up. Conclusions: Perioperative CapeOx therapy demonstrated encouraging 5-year OS and PFS in AGC patients with extensive nodal metastases. These findings support its potential role as a perioperative strategy for biologically high-risk gastric cancer with acceptable safety profiles. Clinical trial information: UMIN000028749 .