Risk factors for lymph node metastasis and evaluation of reasonable surgery for early gastric cancer.

AIM: To give the evidence for rationalizing surgical therapy for early gastric cancer with different lymph node status.
METHODS: A series of 322 early gastric cancer patients who underwent gastrectomy with more than 15 lymph nodes retrieved were reviewed in this study. The rate of lymph node metastasis was calculated. Univariate and multivariate analyses were performed to evaluate the independent factors for predicting lymph node metastasis.
RESULTS: No metastasis was detected in No.5, 6 lymph nodes (LN) during proximal gastric cancer total gastrectomy, and in No.10, 11p, 11d during for combined resection of spleen and splenic artery and in No.15 LN during combined resection of transverse colon mesentery. No.11p, 12a, 14v LN were proved negative for metastasis. The global metastastic rate was 14.6% for LN, 5.9% for mucosa, and 22.4% for submucosa carcinoma, respectively. The metastasis in group II was almost limited in No.7, 8a LN. Multivariate analysis identified that the depth of invasion, histological type and lymphatic invasion were independent risk factors for LN metastasis. No metastasis from distal cancer (<or=1.0 cm in diameter) was detected in group II LN. The metastasis rate increased significantly when the diameter exceeded 3.0 cm. All tumors (<or=1.0 cm in diameter) with LN metastasis and mucosa invasion showed a depressed macroscopic type, and all protruded carcinomas were >3.0 cm in diameter.
CONCLUSION: Segmental/subtotal gastrectomy plus D1/D1+No.7 should be performed for carcinoma (<or=1.0 cm in diameter, protruded type and mucosa invasion). Subtotal gastrectomy plus D2 or D2+No.7, 8a, 9 is the most rational operation, whereas No.11p, 12a, 14v lymphadenectomy should not be recommended routinely for poorly differentiated and depressed type of submucosa carcinoma (>3.0 cm in diameter). Total gastrectomy should not be performed in proximal, so does combined resection or D2+/D3 lymphadenectomy.