Extended D2 lymphadenectomy (D2+) improves outcomes in specific gastric cancer cases.

• Metastatic rates are 8% for stations 12b/12p and 13, and 7% for 14v, with therapeutic value indices (TVI) of 2.6, 2.4, and 3.9, respectively.
• Patients with duodenal invasion show significantly higher TVIs: 3.9 (12b/12p), 3.8 (13), and 9.0 (14v) compared to those without.

Consider D2+ dissection for patients with duodenal invasion or clinical No. 6 metastasis for better surgical outcomes.

• Preoperative duodenal invasion and clinical No. 6 metastasis are strong predictors for 14v involvement.