Prognostic value of the number of metastatic lymph node in patient with biliary tract carcinoma

Introduction: It was known that the prognosis of some carcinoma was correlated with the metastatic lymph node number (MLNN). About biliary tract carcinoma, relationship between MLNN and tumor prognosis was not clearly known. The aim of this study was to investigate the prognostic value of the MLNN in biliary tract carcinoma. Method: This study was retrospective case-control study of patients who underwent surgical treatment for biliary tract carcinoma between January 2006 and July 2017. The relationship between MLNN and overall survival (OS), disease free survival (DFS) and early recurrence within one year after surgery were investigated. Results: During the study periods, 255 patients underwent the surgical resection for biliary tract carcinoma. Increasing the MLNN revealed poor prognosis, especially MLNN≧3 group (median OS; 10.8 months, median DFS; 6.5 months) was significantly poor than that of MLNN=1-2 group (median OS; 55.4 months, median DFS; 15.3 months) (P< 0.001). Multivariate analysis revealed that lymph node metastasis and perineural invasion were independent prognostic factor. About the multivariate analysis of lymph node metastasis positive (N1) patients (n=122), MLNN≧3 was poor prognosis factor (Hazard ratio 2.62, 1.40-4.86 95%CI, P=0.003 in OS, Hazard ratio 2.51, 1.37-4.50 95%CI, P=0.003 in DFS). Early recurrence was occurred significantly frequently in N1 patients (n=61, P< 0.001). Multivariate analysis of N1 patients revealed MLNN≧3 was poor prognosis factor (Odds ratio 2.66, 1.08-6.77 95%CI, P=0.034). Conclusion: MLNN≧3 had significantly poor prognosis in biliary tract carcinoma. It was suggested that MLNN could predict the risk of early recurrence.