Analysis of prognostic factors and influencing factors of lymph node ratio in patients with Siewert II and III adenocarcinoma of the esophagogastric junction

Objective To investigate the prognostic factors and influencing factors of lymph node ratio (LNR) in patients with Siewert Ⅱ and Ⅲ adenocarcinoma of the esophagogastric junction (AEG). Methods The retrospective case-control study was conducted. The clinicopathological data of 444 patients with Siewert Ⅱ and Ⅲ AEG who were admitted to the First Affiliated Hospital of Anhui Medical University between January 2010 and January 2011 were collected. All the 444 patients underwent radical D2 lymph node dissection, extent of lymph node dissection was inferior mediastinum, around the esophageal hiatus and celiac lymph node. Follow-up using telephone interview and outpatient examination was performed to detect patients′ prognosis once every 3 months within 2 years postoperatively, once every 6 months from 2 years to 5 years postoperatively and once every 12 months after 5 years up to October 2016. Observation indicators: (1) follow-up and survival situations; (2) univariate and multivariate factors analysis affecting prognosis of patients with Siewert Ⅱ and Ⅲ AEG; (3) univariate and multivariate factors analysis affecting LNR of patients with Siewert Ⅱ and Ⅲ AEG. The survival curve and rate were respectively drawn and calculated by the Kaplan-Meier method. The univariate analysis and multivariate analysis were respectively done using the Log-rank test and the COX regression model. Results (1) Follow-up and survival situations: all the 444 patients were followed up for 1-81 months, with a median time of 52 months. The 1-, 3-, 5-year overall survival rates of 444 patients were respectively 93.2%, 60.3% and 45.7%. (2) Factors analysis affecting prognosis of patients with Siewert Ⅱ and Ⅲ AEG: results of univariate analysis showed that tumor diameter, tumor differentiation, invasion depth of tumor, pN staging and staging of LNR were related factors affecting prognosis of patients with Siewert Ⅱ and Ⅲ AEG, with statistically significant differences (χ2=12.332, 5.898, 36.045, 38.847, 46.464, P<0.05). Results of multivariate analysis showed that invasion depth of tumor and staging of LNR were independent factors affecting prognosis of patients with Siewert Ⅱ and Ⅲ AEG [RR=1.393, 1.411, 95% confidence interval (CI): 1.137-1.708, 1.106-1.801, P<0.05]. (3) Factors affecting LNR of patients with Siewert Ⅱ and Ⅲ AEG: results of univariate analysis showed that tumor diameter, tumor differentiation and invasion depth of tumor were related factors affecting LNR of patients with Siewert Ⅱ and Ⅲ AEG, with statistically significant differences (χ2=20.077, 12.618, 36.586, P<0.05). Results of multivariate analysis showed that tumor diameter, tumor differentiation and invasion depth of tumor were independent factors affecting LNR of patients with Siewert Ⅱ and Ⅲ AEG (OR=0.684, 0.688, 0.788, 95% CI: 0.485-0.965, 0.505-0.936, 0.687-0.903, P<0.05). Conclusions The invasion depth of tumor and staging of LNR are independent factors affecting prognosis of patients with Siewert Ⅱ and Ⅲ AEG. Tumor diameter, tumor differentiation and invasion depth of tumor are independent factors affecting LNR of patients with Siewert Ⅱ and Ⅲ AEG. Key words: Esophagogastfic junction neoplasms, adenocarcinoma; Lymph node ratio; Prognosis