Application Of The Proposed UICC/AJCC 8^th Edition Staging System Of Esophageal Cancer For Patients Undergoing Radical Radiation Therapy

Objective: In 2017,TNM staging system was revised again.The new staging system included three parts: pathological staging system,neoadjuvant pathological staging system and clinical staging system.The UICC/AJCC 6th edition and the UICC/AJCC 7th edition were based on pathological staging and were not appropriate for patients with esophageal cancer received radical radiotherapy.The purpose of this study was to verify the prognostic value of the new American Joint Committee on Cancer(AJCC)clinical staging system for esophageal cancer patients who undergo radical radiation therapy.Method:We collected the data of esophageal cancer patients treated in Tianjin Medical University Cancer Institute and Hospital from March 2010 to September 2016.Inclusion criteria are as follow:(1)Received IMRT(intensity modulated radiation therapy)(2)Received radical radiotherapy(3)ECOG≤2(4)No distant metastasis.The exclusion criteria are as follows:(1)Received surgery(2)Had serious heart and lung disease.Finally,544 patients with esophageal cancer met the inclusion criteria.T stage,N stage,and total stages were analyzed according to the 6th edition,the 7th edition and the 8th clinical staging systems,respectively.SPSS24.0 software and R language(R-3.4.1)were used for statistical analysis,and chi-square test was performed to detect the differences between groups.The Kaplan-Meier method was used to calculate the survival rate of the patients.The Cox regression model was used for multivariate prognostic analysis.Age,gender,KPS score,concurrent chemoradiotherapy,tumor location,T stage,N stage,6th version stage,7th version stage and 8th version clinical stage were included in the univariate and COX multivariate model analysis to explore the independent risk factors for survival of esophageal cancer patients.Log-rank was used to compare survival rates between groups.P < 0.05 was considered statistically significant.AIC’s Information Criterion(AIC)and c-index(concordance index)were used to evaluate goodness of fit and prediction accuracy of each staging system.Using R language to calculate the AIC value and C-index value of each staging system.Result: 1.All the patients were divided into different groups by 8th AJCC clinical TNM staging system;T2:40 cases;T3:157 cases;T4:347 cases;N0:132 cases;N1:193 cases;N2:172 cases;N3:47 cases;stage II: 81 cases;stage III: 102cases;stage IVA: 361 cases.The 3-year survival rate of stage T2、stage T3、stage T4 were 60.1%,45.6%,30.8%,respectively;(P<0.001).The 3-year survival rate of stage N0、stage N1、stage N2、stage N3 were 48.2%,40.7%,29.4%,17.3%,respectively;(P<0.001).The 3-year survival rate of stage II、stage III、stage IVA were 59.3%,40.1%,31.2%;(P<0.001).2.The 8th clinical stage was compared with the 6th edition staging system and the 7th staging system,to verify the prognostic ability of the 8th edition of clinical staging.In univariate analysis,age,concurrent chemoradiotherapy,T stage,N stage,KPS marking system,UICC/AJCC 6th edition staging system,UICC/AJCC 7th edition staging system and UICC/AJCC 8th edition staging system were the important prognostic factors.In multivariate analysis,concurrent chemoradiation therapy was independent risk factors.3.The median survival time and 1-year,3-year and 5-year survival rates of 544 patients with esophageal cancer were 19.6 months,69.4%,37.2% and 32.3%,respectively.Conclusions: 1.Based on the data from Tianjin Medical University Cancer Institute and Hospital,the 8th edition clinical staging system had a better predict ability than the 6th edition clinical staging system and the 7th edition clinical staging system for esophageal cancer patients who underwent radical radiation therapy.2.Age,concurrent chemoradiotherapy,T stage,N stage,UICC/AJCC 6th edition staging system,UICC/AJCC 7th edition staging system,UICC/AJCC 8th edition staging system,KPS score are important factors affecting the prognosis of esophageal cancer patients.Whether concurrent chemoradiotherapy or not was an independent risk factor for prognosis.3.The results showed that there was little difference between the AIC value and the c-index value of the three staging system,among which the AIC value of the seventh staging system was the smallest and the c-index of the seventh staging system value was the largest,and the 8th edition was second only to the 7th edition.