The Value Of Maximum Diameter Of The Metastatic Lymph Nodes Of Bladder Cancer In TNM Staging System

Objectives:Bladder cancer is a common urogenital tumor and has a high mortality rate worldwide,with a high incidence in men.Metastasis and recurrence are the leading causes of poor prognosis,and regional lymph nodes are the most common metastatic sites in bladder cancer patients.The prognosis of patients with bladder cancer remains dismal,but bladder cancer patients with lymph node metastases constitute a heterogeneous population with a variable prognosis.Accurate staging,with its key role in predicting prognosis and guiding individualized treatment,is the main tool used to stratify these patients into prognostically distinct groups.Our study aimed to evaluate the prognostic significance of the maximum diameter of metastatic lymph nodes(MDMLN)in patients with bladder cancer and to explore the value of the MDMLN in the American Joint Conmittee on Cancer(AJCC)TNM staging system.Methods:We identified 2605 patients treated with cystectomy and lymphadenectomy for bladder cancer between 2010 and 2014 from the Surveillance,Epidemiology,and End Results(SEER)database.The Kaplan-Meier and stepwise multivariate Cox proportional hazards methods were used to analyze overall survival(OS)and cancer-specific survival(CSS)to evaluate the differences in survival associated with different variables.We analyzed the impact of new stratification on distant metastases using a logistic regression model.All the statistical methods are performed using the statistical software SPSS.V20.0Result:The Kaplan-Meier analysis showed that MDMLN was a significant independent predictor of the survival of bladder cancer patients(p<0.001).In the univariate Cox regression model,with regard to OS and CSS,the prognostic value of MDMLN<2 cm was higher than that of node-negative(OS:OR=2.52 p<0.001;CSS:OR=2.84 p<0.001),the prognostic value of MDMLN>2 cm was higher than that of node-negative(OS:OR=4.20 p<0.001;CSS:OR=5.01 p<0.001).In the multivariate Cox regression model,with regard to OS and CSS,the prognostic value of MDMLN<2 cm was higher than that of node-negative(OS:OR=1.82 p<0.001;CSS:OR=1.93 p<0.001),the prognostic value of MDMLN>2 cm was higher than that of node-negative(OS:OR=3.00 p<0.001;CSS:OR=3.30 p<0.001).In the univariate Cox regression model,the other prognostic factors were age,gender,race,7th T stage,7th M stage,7th N stage and the number of lymph nodes examined.In the multivariate Cox regression model,the above factors remained prognostically significant except for the 7th N stage and gender.A proposed stratification based on the 7th edition TNM staging system and the MDMLN was developed.We compared the prognostic value of this stratification with that of the 7th edition TNM nodal staging system.Based on our stratification method,patients were stratified into groups with different prognoses.Moreover,we found that the 7th edition TNM staging system had limited prognostic value in the stratification of patients with lymph node metastases.Conclusion:This study indicates that the MDMLN is a significant independent prognostic factor for the survival of bladder cancer patients.The MDMLN may supplement the current TNM nodal staging system to help stratify bladder cancer patients into prognostically distinct groups.