Clinicopathological Characteristics of Superficially Spreading Early Gastric Cancer

ABSTRACT

PURPOSE: Superficially spreading (SS) early gastric cancer (EGC) is characterized by wide horizontal extension without deep vertical invasion. It is a relatively rare form of EGC, and it's clinicopathological (C-P) characteristics are not evident. This study aimed to clarify their C-P characteristics. MATERIALS AND METHODS: We defined SS EGC as invading less than the submucosal layer that measured more than 60 mm in diameter or wider than 5 x 5 cm (25 cm2) in width. The C-P characteristics and prognosis were compared between 69 patients with SS EGC and 319 patients with the common type EGC (EGC except SS type). RESULTS: For SS EGC, lymph node metastases, Lauren's diffuse type, lymphatic invasion were significantly higher than in common type EGC. In patients with SS EGC, all of the metastatic lymph nodes were anatomically distributed within the paragastric region, with fewer along the left gastric artery and common hepatic artery. In 6 cases of SS EGC with resection margins less than 10 mm, there was no death during the follow-up period (4 to 13 years after operation) if margins were not involved. Age (>58 yrs), tumor site (upper 1/3), lymph node metastasis, submucosal invasion were statistically significant poor prognostic factor in univariate survival analysis. In multivariate survival analysis, age and lymph node metastasis were independent prognostic factors. However, tumor diameter or width was not a significant prognostic factor. CONCLUSION: Although SS EGC has histologically distinct properties, gastrectomy with free surgical margins and appropriate lymph node dissection (D1+beta) could be a suitable treatment.