Risk Stratification Of Recurrent Laryngeal Nerve Lymph Node Metastasis In Thoracolaparoscopic Esophagectomy

PurposeTo analyze the risk factors of recurrent laryngeal nerve lymph node metastasis in thoracolaparoscopic esophagectomy,and to establish a prediction model and risk stratification of recurrent laryngeal nerve lymph node metastasis in thoracic esophageal squamous cell carcinoma.MethodA retrospective case-control study was conducted to collect the clinical data of 413 patients with thoracic esophageal squamous cell carcinoma who underwent thoracic laparoscopic radical esophagectomy combined with systematic lymph node dissection in The First Affiliated Hospital of Zhengzhou University from February 2015 to April 2020.Including preoperative data:age(≤ 64 years old,>64 years old),gender(male,female),smoking history(smoking history,no smoking history),drinking history(drinking history,no drinking history),family history(family history,no family history),tumor site(upper thoracic,middle and lower thoracic),CT lymph node abnormalities(short diameter≥ 8mm,unclear margin,central necrosis),postoperative tumor diameter(≤3cm,>3cm and ≤5cm).>5cm),T stage of pathology(T1,T 2,T2,T3).SPSS statistical software was used to analyze the data.The data of classified variables in clinicopathological factors were processed byχ2 test to transform into biased distribution data of classified variables;t-test was selected and represented by X±S to analyze the continuous variable data in accordance with normal distribution;Logistic regression model was used for multivariate analysis of lymph nodes adjacent to the recurrent laryngeal nerve.Based on the results of multivariate analysis,the nomogram recurrent laryngeal nerve lymph node prediction model was constructed by Rstudio software.After c-index verification,the decision tree model was constructed by using "recursive segmentation analysis(PRA)".The difference was statistically significant(P<0.05).ResultsAccording to the study of 413 patients with thoracic esophageal squamous cell carcinoma,103 cases had recurrent laryngeal nerve lymph node metastasis,and the rate of recurrent laryngeal nerve lymph node metastasis was 24.94%(103/413).The risk factors of recurrent laryngeal nerve lymph node metastasis were tumor location,tumor differentiation,lymph node abnormality under CT,T stage and tumor length.Tumor location,T stage and abnormal lymph nodes under CTwere independent risk factors for lymph node metastasis adjacent to the recurrent laryngeal nerve.A nomogram model of lymph node metastasis adjacent to the recurrent laryngeal nerve was established according to independent risk factors.The c-index of the prediction model is 0.721,and the correction curve shows that the actual transfer probability of the prediction model coincides with the prediction probability to a certain extent.The decision curve shows that when the threshold is 0.182 to 0.531,when the prediction model is in this range,it has the best benefit.The decision tree model is constructed by using "Recursive Segmentation Analysis(PRA)".According to the probability of recurrent laryngeal nerve lymph node metastasis combined with CT lymph node abnormality,T stage and tumor location,the patients were divided into four risk subgroups:low risk group(13.4%),medium and low risk group(25.4%),medium and high risk group(40%)and high risk group(60%).Conclusion1.Tumor location,abnormal lymph nodes under CT and pathological T stage were independent risk factors for recurrent laryngeal nerve lymph node metastasis in thoracic esophageal squamous cell carcinoma.The nomogram model established on this basis can accurately predict the probability of lymph node metastasis adjacent to the recurrent laryngeal nerve.2.According to the results of decision tree model,lymph node abnormalities under CT had the greatest influence on recurrent laryngeal nerve lymph node metastasis,followed by pathological T stage and tumor location.According to the risk stratification results of the prediction model and the decision tree model,it can provide ideas for the scope of lymph node dissection.