Background: Many investigators have reported that extended lymph node dissection (D2 dissection) is probably an effective procedure. However, the theory that D2 dissection leads to an improvement in survival has not been confirmed in randomized trials. We attempted to confirm the effectiveness of D2 dissection with gastrectomy for gastric cancer.
Materials and methods: Gastric cancer patients (1403) underwent curative resection by D1 (991 patients) or D2 (412 patients) dissection with gastrectomy. Survival rates calculated for all patients and subdivided for stage, depth of invasion, and lymph node metastasis were compared between the two groups. The diagnosis of lymph node metastasis was compared between macroscopic and histological findings.
Results: There was no significant difference in the survival of patients overall. However, in the patients with stage II, T1 or T2, or N1 disease, the survival of the D2 group was significantly better than that of the D1 group. The false positive rates of lymph node metastasis were 53.3% in the N1 group, 26.2% in the N2 group, and 9.2% in the N3 group. In a considerable proportion of the N1 and N2 patients, histological findings proved more or fewer metastases than macroscopic diagnosis.
Conclusions: Metastatic lymph nodes should be resected as far as possible. D2 dissection with gastrectomy is recommended for T1, N1 or T2, N1 disease, particularly in younger patients.