Prognostic Factors Analysis Of Adenocarcinoma Of Esophagogastric Junction And Comparative Study On The Accuracy Of Prognostic Evaluation Of Different TNM Staging Systems

Background:Adenocarcinoma of esophagogastric junction(AEG)is a special type of malignant tumor which occurs in the upper gastrointestinal tract.Anatomical location of AEG is within the upper and lower 5cm of the esophagogastric junction(EGJ).The incidence of AEG has been increasing in recent years,and more and more attention has been paid to AEG.AEG occurs in the distal esophageal and proximal gastric regions,straddling the chest and abdomen at the same time.However,AEG is different from esophageal or gastric cancer.Its biological behavior is complicated and prognosis is poor.Even after radical resection,the overall 5-year survival rate is still very low.An in-depth analysis of the prognostic factors in patients with AEG may indicate a certain direction for clinical treatment and decision-making as well as for improving the prognosis of patients with AEG.Although some researchers have explored the factors influencing the prognosis of AEG,the independent prognostic factors are still unclear,which need to be further studied.In the 7th edition TNM staging manual of malignant tumors of American Joint Committee on Cancer(AJCC),the classification of AEG was described as follows:the staging of AEG should be treated as esophageal carcinoma.At the end of 2016,in the 8th edition TNM staging manual of malignant tumors issued by AJCC,the classification of AEG has been changed greatly compared with the 7th edition,which can be summarized as"2cm principle":when the tumor epicenter is located outside the 2cm below the EGJ or within the 2cm below the EGJ but not invading the EGJ,it is treated according to the TNM staging of gastric cancer;when the tumor epicenter is within the 2cm of EGJ and invades the EGJ,it is treated according to the TNM staging of esophageal carcinoma.Obviously,Siewert ? AEG,classified as esophageal carcinoma in the 7th edition TNM staging system,is defined as gastric cancer in the 8th edition.However,whether the 8th editionTNM staging system is more reasonable than the 7th edition,and whether the prognostic prediction ability is better or not,in-depth research and verification are needed to explain.Methods:1.The clinical data of patients with AEG who underwent surgical treatment in PLA general hospital from January 2009 to January 2013 were collected retrospectively.According to the inclusion and exclusion criteria,a total of 343 patients with AEG were included in the study.Sex,age,co-morbidity,Siewert classification,tumor size(Diameter),differentiation,vascular cancer embolus,nerve invasion,T-stage,N stage,pTNM,approach,minimally invasive surgery,resection scope,adjuvant chemotherapy,HER-2 and Ki-67 expression were analyzed comprehensively to study the independent or nonindependent prognostic factors in patients with AEG.2.The clinical data of Siewert ? AEG patients undergoing radical(R0)resection in PLA general hospital from January 2009 to January 2013 were collected retrospectively.According to the inclusion and exclusion criteria,a total of 160 Siewert ? AEG patients were included in the study.G7,G8 and E7 staging systems were used to re-stage the patients,and the superiorities of different staging systems in Siewert ? AEG patients were compared.Results:1.The median follow-up time of the 343 patients with AEG was 50.2 months.The 5-year overall survival rate of the whole group(without ? stage patients)was 49.2%.Univariate analysis showed that age,co-morbidity,Siewert classification,tumor size(Diameter),differentiation,vascular cancer embolus,nerve invasion,T-stage,N stage,pTNM,adjuvant chemotherapy,level of Ki-67 expression was correlated with prognosis(P<0 05).Multivariate analysis showed that age,tumor size(Diameter),differentiation,pTNM and adjuvant chemotherapy were independent prognostic factors affecting the overall survival of the patients(P<0 05).2.The median follow-up time of 160 patients with Siewert ? AEG was 49.3 months,and the overall 5-year survival rate was 56.26%.Compared between G7 and G8,the stage migration rate was 8.1%(13/160).The consistency test showed that the two staging systems had better consistency(weighted Kappa=0.904,P<0.001).Compared between E7 and G8,the stage migration rate was 40.6%(65/160),and the consistency test showed that the two staging systems had poor consistency(weighted Kappa=0.536,P<0.001).The comparison of AIC values of different staging systems showed that the AIC value of G8 staging system was 811.4,which was lower than that of G7 staging system(812.8)and E7 staging system(815.9).Conclusion:1.The age,tumor size(Diameter),differentiation degree,pTNM and adjuvant chemotherapy were independent prognostic factors affecting the overall survival rate of patients with AEG(P<0 05).2.For Siewert ? AEG,G8 staging system was superior to G7 staging system in the prognostic value,while G7 staging system was superior to E7 staging system.The G8 performed better than the other two staging systems.Therefore,this study supports that Siewert ? AEG shoud be staged according to gastric cancer staging system.