Association of lymphadenectomy extent with long-term survival in gastric cancer: a retrospective comparative cohort study

INTRODUCTION: The optimal extent of lymphadenectomy for gastric cancer remains controversial, particularly in Western practice, where concerns regarding postoperative morbidity have historically limited the widespread adoption of D2 dissection. This study aimed to compare the perioperative safety and long-term oncological outcomes of D1 and D2 lymphadenectomy in patients undergoing curative gastrectomy.
METHODS: A retrospective comparative cohort study was conducted involving 189 patients who underwent curative gastrectomy for gastric adenocarcinoma between 2014 and 2022. Fifty-seven patients underwent D1 lymphadenectomy, and 132 underwent standard D2 lymphadenectomy according to Japanese Gastric Cancer Association criteria. Baseline clinicopathological characteristics, postoperative outcomes, disease-free survival (DFS), and overall survival (OS) were analyzed. Survival outcomes were evaluated using Kaplan–Meier analysis and Cox proportional hazards regression.
RESULTS: Baseline demographic, clinical, and pathological characteristics were comparable between the groups. The D2 group had a significantly greater number of harvested lymph nodes than the D1 group (median, 31 vs. 27; p=0.011), while postoperative morbidity (18.2% vs. 12.3%; p=0.429), hospital stay (p=0.400), recurrence (p=0.525), and 90-day mortality (p=0.533) were similar. Median overall survival was significantly longer following D2 lymphadenectomy (59 vs. 20 months). One-, three-, and five-year overall survival rates were consistently higher in the D2 group (83.3%, 59.5%, and 49.3%, respectively) than in the D1 group (64.6%, 35.6%, and 31.9%, respectively). Cox regression demonstrated that D2 lymphadenectomy reduced the risk of all-cause mortality by 41% (HR, 0.59; 95% CI, 0.40–0.87). Disease-free survival also favored D2 lymphadenectomy (HR, 0.62; 95% CI, 0.39–1.00), although the difference narrowly missed conventional statistical significance (p=0.052).
DISCUSSION AND CONCLUSION: Standard D2 lymphadenectomy provides superior long-term survival without increasing perioperative morbidity or mortality when performed in experienced centers. These findings support D2 lymphadenectomy as the preferred surgical approach for patients undergoing curative gastrectomy for gastric cancer.

Keywords: D2 lymphadenectomy, disease-free survival, gastric cancer, gastrectomy, overall survival