Introduction
Gastric cancer with extensive lymph node metastasis carries a poor prognosis and presents major challenges in surgical management. In Japan, neoadjuvant chemotherapy followed by D2 gastrectomy with para-aortic lymph node dissection (PAND) has been explored as an aggressive multimodal strategy for patients with bulky nodal disease and/or para-aortic lymph node (PAN) involvement. However, the true therapeutic contribution of PAND remains uncertain.
Problem Statement
Although PAND has historically been incorporated into treatment strategies for advanced nodal gastric cancer, improvements in systemic chemotherapy may have altered the clinical relevance of extended lymphadenectomy. Determining whether PAND continues to provide meaningful survival benefit—particularly across biologically distinct nodal subgroups—is essential to avoid unnecessary surgical morbidity while preserving oncologic benefit.
Summary
This integrated analysis of three JCOG phase II trials evaluated the therapeutic value of PAND in gastric cancer with extensive lymph node metastasis after neoadjuvant chemotherapy. The findings suggest that the clinical utility of PAND differs substantially according to nodal disease pattern. In patients with bulky nodal disease without para-aortic involvement, PAND retained a modest therapeutic value, supporting the possibility that selected patients may still derive benefit from extended nodal dissection. In contrast, patients with clinically evident para-aortic metastasis demonstrated very limited benefit from PAND, particularly in the more recent chemotherapy trials where the therapeutic value index approached zero. Importantly, the incidence of para-aortic metastasis progressively decreased across successive studies, likely reflecting improvements in systemic therapy and better disease control before surgery. These observations suggest that advances in neoadjuvant chemotherapy may be reducing the incremental value of aggressive para-aortic surgery. The study supports a more individualized surgical strategy in advanced gastric cancer and emphasizes that decisions regarding omission or retention of PAND should be tailored separately for bulky nodal disease and para-aortic metastatic disease rather than treating these populations as a single entity.