Characterization of early gastric cancer and proposal of the optimal therapeutic strategy.

Background And Aims: The optimal protocol of the treatment for early gastric cancer has not been fully established. The current study was designed to elucidate the relationship between the depth of tumors with or without an ulcer and the presence of lymph node metastasis and to establish the optimal and practical therapeutic strategy for patients with early gastric cancer.

Patients And Methods: A retrospective analysis of 1051 patients with early gastric cancer treated by gastrectomy with D1 or D2 lymph node dissection was performed. The patients were divided into those with mucosal (M) tumors and those with submucosal (SM) tumors. These 2 groups were subclassified, depending on the coexistence of ulcer or the degree of submucosal invasion, and were characterized in relation to clinicopathologic factors and 5-year prognosis.

Results: The incidence of lymph node metastases from SM tumors (19.8%, 85 of 430) was more frequent than that from M tumors (2.3%, 14 of 621) (P <.001). All M tumors with lymph node involvement, including tumors smaller than 1.5 cm in diameter, had ulceration or ulceration scar in the lesions. SM tumors that had invaded less than 200 microm in depth (SM1a) had significantly less lymph node involvement than those with deeper invasion. The node metastases were confined to epigastric lymph nodes (N1) in both M tumors with ulceration or ulceration scar and SM1a tumors.

Conclusions: All macroscopic M tumors without ulceration or ulceration scar should be considered for endoscopic mucosal resection. The need for reoperation for a formal gastrectomy with lymphadenectomy or a limited surgical operation will vary depending on the pathologic analysis of endoscopic mucosal resection specimens (depth of invasion, presence of ulceration).