Risk Factors And Prognostic Analysis Of Subcarinal Lymph Node Metastasis In Patients With Esophageal Squamous Cell Carcinoma

Objective:The 7th edition of the American Joint Committee on Cancer on Cancer Staging Manual for esophageal cancer categorizes N stage according to the number of metastatic lymph nodes,irrespective of the site. To assess the metastatic frequency of subcarinal lymph nodes of thoracic esophageal carcinoma and its risk factors and prognostic analysis,in order to determine the prognostic value of subcarinal lymph nodes metastasis in patients undergoing esophagectomy for thoracic esophageal squamous cell carcinoma.Methods:A retrospective analysis of 205 consecutive patients with esophageal squamous cell carcinoma was conducted in Affilitated Union Hospital of Fujian Medical University from January 2008 to March 2010.Potential clinicopathological factors that could influence subcarinal lymph nodes metastasis were staltistically analyzed.The difference between groups was evaluated by the Chi-square test for categorical data.Correlation was determined by Spearman analysis.Significant factors were extracted for further anslysis,which was conducted by using logistic regression.Survival rate was calculated using the Kaplan-Meier method.The difference in survival rate was analyzed by the log-rank test.Multivariate analyses of COX proportional hazards model were performed to evaluate the prognostic parameters for survial.Results:Among the 205 patients,the frequency of subcarinal LN metastasis in tumor length >3cm and ≤3cm was 2.3% and 16.0%( P=0.018);for tis, upper,middle and lower esophageal carcinoma were 8.3%,10.0%and 26.8% respectively(P=0.015);for tis, well,moderately and poorly differentiation of esophageal carcinoma were 4.4%,16.5%and 22.7% respectively(P=0.024);for tis,vessel involvement in esophageal carcinoma were 25.8 % and 10.9 % respectively(P=0.024);for tis,perineural invasion in esophageal carcinoma were 20.0%and 7.3% respectively(P=0.007);for tis,Tl,T2,T3 and T4,they were 3.1%,2.3%,15.9% and 41.1% respectively(P=0.000).A logistic regression analysis showed that tumor length(≤3cm vs >3cm; P=0.031), tumor location(Lower vs Upper/Middle;P=0.008), vessel involvement(Yes vs No;P=0.023) and depth of invasion(T3-4a vs T1-2; P=0.013) was considered to be statistically significant.The 5-year survial in patients with subcarinal lymph node metastasis were less than in patients without subcarinal lymph node metastasis(14.8% vs 45.5%,P=0.003).According to univariate analyses, tumor length(≤3cm vs >3cm;P<0.0001),differentiation( poor vs well/moderate; P=0.0016),vessel involvement(yes vs no;P<0.0001),perineural invasion(yes vs no;P=0.0019),depth of invasioon(T3-4 vs T1-2;P<0.0001)and subcarinal LN metastasis(yes vs no;P<0.0001)was considered to be statistically significant. According to multivariate analyses, differentiation(poor vs well/moderate;P=0.041),vessel involvement(yes vs no;P=0.032),perineural invasion(yes vs no;P=0.014)and subcarinal LN metastasis(yes vs no;P=0.021)was considered to be statistically significant.Conclusions:1.Tumour length,tumour location,vessel involvement and the depth of invasion is the risk factor of subcarinal lymph node metastasis in thoracic esophageal carcinoma.2.Differentiation,vessel involvement, the depth of invasion and subcarinal LN metastasis were key factors affecting the prognosis in patients undergoing esophagectomy for ESCC.3.Patients with subcarinal LN metastasis had a poor prognosis.4.Subcarinal LN metastasis is a predictive factor for long-term survival in patients with ESCC.