Background: Superficially spreading cancer (SSC) of the stomach is rare and extends widely along the mucosa or submucosa of the stomach. This study was conducted to clarify the clinicopathologic characteristics and prognosis of patients with SSC.
Methods: SSC was defined as a tumor invading the mucosa or submucosa and measuring > or =5 cm in size. The clinicopathologic findings and outcomes of 36 patients with SSC were compared with those of 300 patients with early gastric cancer (EGC) measuring < or =5 cm and 271 with advanced gastric cancer measuring > or =5 cm.
Results: SSC was significantly different from ordinary EGC in tumor size, frequency of lymph node metastasis, lymphatic invasion, venous invasion, and stage II, III, and IV disease. The frequency of serosal invasion, lymph node metastasis, and lymphatic and venous invasions in cases of SSC was significantly lower than with advanced gastric cancer. Although tumor size of SSC evaluated before operation was smaller than that on the resected specimen, the 10-year survival rate was not different between SSC and ordinary EGC.
Conclusions: SSC was characterized by high frequency of lymph node metastasis and preoperative underestimation of tumor size. SSC should be treated by a gastrectomy and lymphadenectomy with sufficient resection margin.