Rationale for extensive lymphadenectomy in early gastric carcinoma.

The incidence of nodal metastasis in early gastric carcinoma (EGC) is 10-20%. However, the optimal nodal dissection for early gastric carcinoma has not been established. A retrospective study was conducted in 392 consecutive patients who underwent potentially curative distal gastrectomy for EGC between 1962 and 1990. Of these 295 patients treated after September 1972 were prospectively entered into an extensive lymphadenectomy protocol. These patients were compared with 97 patients with simple gastrectomy in respect of the causes of death after surgery and the 10 year disease-specific survival rate. The incidence of nodal metastasis in early gastric carcinoma patients was 13.0%. Operative mortality from extensive lymphadenectomy was almost the same as from simple gastrectomy (2.0% and 2.1% respectively). Extensive lymphadenectomy provided a significantly higher 10 year survival rate than limited lymph node dissection (97.9% vs 88.1% respectively; P < 0.005). Among patients with nodal metastasis, the survival rate following extensive lymphadenectomy was significantly higher than that after simple gastrectomy (87.5% vs 55.6%; P = 0.018). Among patients without nodal metastasis, there was no difference between the two groups in the survival rate (99.4% and 96.7% respectively; P = 0.12). Multivariate analysis using the Cox proportional hazards model disclosed two significant independent prognostic factors on disease-specific survival, the nodal involvement (risk ratio: 8.4; P < 0.0001) and the extent of lymph node dissection (risk ratio: 5.8; P < 0.005). Extensive nodel dissection appears to prevent recurrence and to improve the cancer-specific survival in EGC patients with nodal metastasis.