Efficacy of D2 plus lymph node dissection for gastric cancer.

[BACKGROUND] Locally advanced gastric cancer is usually treated with D2 lymphadenectomy, although extended D2+ dissection (Nos. 12b, 12p, 13, and 14v) is occasionally performed. This study evaluated the efficacy and optimal indications for D2+ lymphadenectomy based on the therapeutic value index (TVI).

[MATERIALS AND METHODS] Patients undergoing curative gastrectomy with D2+ lymphadenectomy (n = 373) were retrospectively analyzed. The TVI for each station was calculated by multiplying the metastatic rate by the 5-year survival rate. Factors associated with lymph node metastasis were identified via multivariate logistic regression analysis.

[RESULTS] The metastatic rate and TVI, respectively, were 8 % and 2.6 for No. 12b/12p, 8 % and 2.4 for No. 13, and 7 % and 3.9 for No. 14v. Higher TVIs were seen among patients with duodenal invasion versus those without (No. 12b/12p, 3.9 vs. 0; No. 13, 3.8 vs. 0; No. 14v, 9.0 vs. 2.7). On multivariate analysis, preoperative duodenal invasion (odds ratio 2.59 [95 % confidence interval, 1.06-6.31]; p = 0.037) and clinical No. 6 metastasis (odds ratio 3.96 [95 % confidence interval, 1.63-9.63]; p = 0.002) were independent predictors of No. 14v involvement.

[CONCLUSIONS] Dissection of Nos. 12b, 12p, and 13 may be beneficial in patients with duodenal invasion. No. 14v dissection should be considered in patients with clinical No. 6 involvement or duodenal invasion.