Indications of limited surgery for gastric cancer with submucosal invasion--analysis of 715 cases with special reference to site of the tumor and level 2 lymph nodes.

Background/aims: There is controversy as to whether limited or extended lymph node dissection should be performed for gastric cancer with submucosal invasion.

Methodology: To clarify the indications of limited surgery for gastric cancer invading the submucosa, we retrospectively examined the incidence of lymph node metastases with regard to the location of the tumor and distant lymph node station in 715 patients who underwent curative gastrectomy with D2 lymphadenectomy for gastric cancer with submucosal invasion. We classified the level 2 lymph nodes into four groups as follows: group 1 was defined as perigastric lymph nodes far from the primary tumors, group 2 as nodes around the left gastric and the common hepatic arteries, group 3 as nodes around the celiac axis, and group 4 as nodes along the splenic artery.

Results: The occurrence of the metastases to level 1 nodes was 14.5% (104 of 715) and that to level 2 nodes was 4.5% (32 of 715). Among the latter, metastases to group 1 lymph nodes were detected in 6 only in the lower third (2.1%) and that to group 2 in 5 in the upper third (6.2%), 9 in the middle third (2.6%), and 12 in the lower third of the stomach (4.1%). Metastases to groups 3 and 4 were only recognized in 2 in the middle third of the stomach (0.3%). Tumors less than 8 mm did not metastasize to lymph nodes and those less than 12 mm did not metastasize to distant ones.

Conclusions: These results suggested that in gastric cancer invading the submucosa, it would be sufficient to dissect group 2 lymph nodes for tumors located at the upper third or the middle third of the stomach, and for tumors located in the lower third of the stomach nodes of groups 1 and 2 should be dissected. For tumors less than 8 mm in the diameter partial resection alone could do and for those less than 12 mm D1 dissection is recommended.