Prognostic Value Of Lymph Node Parameters In Long-term Survival Of Patients With Distal Cholangiocarcinoma After Operation

Objective: This study retrospectively analyzed the relationship between postoperative clinicopathologic features and survival in patients with distal cholangiocarcinoma.We further explored the prognostic value of lymph node-related parameters(positive lymph node count,lymph node ratio,and negative lymph node count,etc.)after surgical resection of distal cholangiocarcinoma to help clinicians identify patients with poor prognosis.Methods: A total of 448 patients with distal cholangiocarcinoma surgically resected from 2000 to 2014 were screened from the Surveillance,Epidemiology and End Results(SEER)database of the American National Cancer Institute.X-tile software was used to determine the optimal cut-off point for parameters such as positive lymph node count and lymph node ratio.We evaluated the effects of lymph node parameters and other clinicopathological features on the prognosis of patients by univariate survival analysis.Then,the factors that were statistically significant withprognosis of patient in univariate analysis were included in the COX regression analysis to assess postoperative independent risk factors for patients with distal cholangiocarcinoma.Results: Of the patients enrolled,223(49.8%)were diagnosed with lymph node metastases.The optimal cut-off points of lymph node ratio and positive lymph node count were 0.45 and 3,respectively.Univariate analysis indicated that lymph node ratio,tumor size,AJCC stage,and positive lymph node count were significantly correlated with the prognosis of patients(P <0.05).COX multivariate regression analysis showed that only lymph node ratio was an independent prognostic factor affecting overall survival(HR,2.183;P <0.001)and cancer-specific survival(HR2.515;P <0.001),whereas positive lymph node count was not.We further analyzed the prognostic factors in the subgroup of patients with lymph node metastasis.The results found that the patients with a lymph node ratio of more than 0.45 had significantly worse overall survival(HR,2.149;P<0.001)and cancer-specific survival(HR,2.418;P <0.001)than those with a lymph node ratio of 0.45 or less.Conclusion: Lymph node ratio can better predict the long-term survival of patients after surgery than the positive lymph node count.In addition,lymph node ratio is an independent predictive factor for survival in patients with distal cholangiocarcinoma,which has important clinical significance in predicting the prognosis of patients.Patients with a lymphnode ratio of more than 0.45 have significantly poorer prognosis and may require further adjuvant therapy to improve their long-term survival.