Risk factors of vagus nerve invasion in patients with advanced adenocarcinoma of esophagogastric junction

Objective To investigate the risk factors of vagus nerve invasion of advanced adenocarcinoma of esophagogastric junction (AEG).Methods The specimens from 98 patients with advanced AEG who underwent radical total gastrectomy and esophagogastric Roux-en-Y anastomosis from January 2011 to August 2012 at the First Affiliated Hospital of Anhui Medical University were collected.Serial section cutting was done and the upper and bottom incisional edges of every section were marked.The specimens were stained by hematoxylin-eosin solution,S-100 and CK immunohistochemistry.Vagus nerve invasion could be affirmed if cancer cells were observed in the peripheral space of vagus nerve and vagus nerve parenchyma or cancer cells infiltrated along the peripheral space of vagus nerve.Relationship between nerve invasion and clinicopathological factors was analyzed using chi-square test or Fisher exact probability.Factors related to vagus nerve invasion were analyzed using one-way analysis of variance and multi-factor logistic regression analysis.Results The incidence of vagus nerve invasion was 28.6％ (28/98),and the tumor only invaded the vagus nerve which had the same altitude as the upper incisional edge.The results of one-way analysis of variance showed that Siewert classification,intravascular cancer emboli,lymph node metastasis,the degree of lymph node metastasis,clinical staging,the degree of tumor differentiation were correlated with the vagus nerve invasion (x2 =14.156,14.552,5.454,10.706,6.919,14.767,P ＜ 0.05).The results of multi-factor logistic regression analysis showed that Siewert classification,intravascular cancer emboli and degree of tumor differentiation were the independent influencing factors of vague nerve invasion (OR =3.667,10.368,0.249,P ＜ 0.05).Conclusion Vagus nerve invasion is correlated with Siewert classification,intravascular cancer emboli and degree of tumor differentiation.The range of vagus nerve invasion is restricted under the upper incisional edge of tumor section. Key words: Carcinoma of esophagogastric junction;  Vagus nerve ;  Neural invasion