[Evaluation of the value of 7th editions of UICC-AJCC esophageal and gastric cancer TNM staging systems for prognostic prediction of adenocarcinoma of esophagogastric junction (Siewert type II)].

ABSTRACT

OBJECTIVE: To compare the value of applicability of the 7th edition of UICC-AJCC esophageal and gastric cancer TNM staging system in the prognostic prediction of adenocarcinoma of esophagogastric junction (EGJ). METHODS: During June 1, 2007 through Dec. 31, 2010, a total of 199 patients with adenocarcinoma of esophagogastric junction (Siewert type II) underwent R0-intent resection from June 1, 2007 to Dec 31, 2010 in our hospital. Their clinicopathological and survival data were retrospectively analyzed with Kaplan-Meier and Cox regression models. They were restaged according to the 7th edition of UICC/AJCC TNM stage systems for esophageal adenocarcinoma and gastric cancer, respectively. Then the likelihood ratio chi-square test related to the Cox regression model and Akaike information criterion (AIC) were used for measuring goodness of fit for both staging systems. RESULTS: 199 patients with Siewert type II esophagogastric junction adenocarcinoma were identified in this study. Out of them, there were 162 males and 37 females. Their age range was from 38 to 79 years, with a median age of 62 years. 176 cases underwent transthoracic surgery, and other 23 cases underwent transabdominal surgery. TNM-EC and TNM-GC classified 4 patients to stage T1, 39 to T2, 139 to T3, and 17 to T4a, respectively, and classified 76 patients to stage N0, 58 to N1, 49 to N2, 16 to N3, respectively. The median follow-up period was 30 months. The 1-, 3-, and 5-year survival rates were 95.0%, 52.7% and 39.2%, respectively. Univariate analysis indicated that age at surgery (P = 0.009), surgical approach (P = 0.002), cell differentiation (P = 0.030), preoperative co-morbidity implications (P = 0.026), depth of tumor invasion (P < 0.001) and number of metastatic lymph nodes (P < 0.001) were significantly influencing factors of postoperative overall survival. Multivariate analysis showed that the independent prognostic factors for adenocarcinoma of esophagogastric junction were only T stage, N stage and preoperative co-morbidity and morbidities according to the 7th edition of esophageal cancer or gastric cancer TNM staging systems. The AIC value was 961.4 for the 7th edition of esophageal adenocarcinoma caner staging system, and 965.7 for the 7th edition of gastric cancer staging system. CONCLUSIONS: The UICC/AJCC 7th edition of esophageal adenocarcinoma cancer TNM classification staging system is superior to the 7th edition of gastric cancer TNM staging system for adenocarcinoma of esophagogastric junction.