OBJECTIVETo evaluate the relationship between serosal invasion types and lymph node metastasis after total gastrectomy in gastric cancer patients, and explore its significance in planning practice rational dissection based on the serosa types of gastric cancer during surgery.

METHODSA total of 73 gastric cancer patients, who underwent total gastrectomy and lymph node dissection, were included in this study, and their clinicopathological data were analyzed. The serosa of gastric cancer was divided into five types: normal, reactive, nodular, tendonoid, and color-diffused, then they were combined into 3 groups: group 1: normal and reactive, group 2: nodular (including protruding nodular and flat nodular), and group 3: tendonoid and color-diffused. The lymph node metastasis ratios in the 3 groups were compared. The lymph nodes in each of the 3 groups were divided into 16 subgroups and the lymph node metastasis ratios of each subgroup in the 3 groups were compared and analyzed.

RESULTSThe lymph node metastasis ratio of the gastric cancer with normal and reactive type serosa was 5.3% (26/492), the nodular was 37.1% (250/673), the tendonoid and color-diffused was 50.0% (486/972). The lymph node metastasis ratio of normal and reactive type groups was the lowest, that of the tendonoid and color-diffused groups was the highest, and the nodular type in between, showing a statistically significant difference (P<0.01). The results of comparing the lymph node metastasis ratios from the 1st to 16th subgroup in the 3 groups showed the same trend (P<0.05).

CONCLUSIONAmong all serosa types of gastric cancer, the lymph node metastasis ratio of the tendonoid and color-diffused is the highest, the normal and reactive type is the lowest, and the nodular in between. The extent of rational dissection should be carried out on the basis of serosa types of gastric cancer during surgery. An extended dissection including D2 and D3 lymphadenectomy should be performed for the patients with tendonoid and color-diffused serosa, a rational decreased operation including D1-D1+ lymphadenectomy should be performed for those with a normal and reactive type serosa, and for the patients with nodular type serosa, we suggest performing standard D2 dissection.