Penetrating serosa in human T4aN0M0 gastric carcinoma correlates closely to patients’ worse prognosis after D2 gastrectomy

BACKGROUND AND OBJECTIVE: In both the 7th edition of the UICC staging system for gastric cancer and the 14th edition of the JGCA system, the definition of T4a is “Tumor perforates serosa (visceral peritoneum) without invasion of adjacent structures”. The aim of this study is to investigate the prognostic difference between T4aN0M0 patients with serosa-penetrating and without serosa-penetrating of gastric carcinoma. METHODS: A total of 221 patients with T4aN0M0 gastric carcinoma who underwent D2 resection at our Cancer Center between January 1990 and December 2008 were collected. The cohort included 42 patients with serosa-penetrating and 179 patients without serosa-penetrating. Average follow-up time was 85.5 months. Spearman’s rank correlation, Kaplan-Meier plots and Cox proportional hazards regression model were used to analyze the data. RESULTS: The 5-year survival rate for the patients serosa-penetrating and the patients without serosa-penetrating were 31% and 62% respectively (p<0.05). The relapse rates of these two groups after D2 radical surgery were 16.2% and 59.5%, respectively (p<0.05). The peritoneal dissemination and distant organ/lymph node metastatic rates were 44.8% and 55.2% versus 76.0% and 24.0%, respectively (p<0.05). CONCLUSION: Our findings provide a basis for the concept that serosa-penetrating in T4aN0M0 gastric carcinoma may be important in the acquisition of an aggressive phenotype, suggesting that serosa-penetrating, is an independent factor for poor prognosis of patients with gastric carcinoma.