Impact of serum carbohydrate antigen 19-9 level on prognosis and prediction of lymph node metastasis in patients with intrahepatic cholangiocarcinoma

Background and AimLymph node metastasis is an important prognostic factor for intrahepatic cholangiocarcinoma (ICC), but accurate preoperative diagnosis is difficult. The aim of this study was to measure the concentration of serum carbohydrate antigen 19-9 (s-CA19-9) as a preoperative predictor of lymph node metastasis. MethodsIn our department, curative-intent hepatectomy for ICC has been performed only once the absence of metastases in para-aortic lymph nodes (PALN) has been confirmed from intraoperative frozen-section pathological examinations. The present study included 13 non-resected ICC patients with PALN metastasis (PALN group) and 44 resected ICC patients without PALN metastasis (non-PALN group). S-CA19-9 was examined to evaluate predictive performance for PALN metastasis and regional lymph node metastasis (pN1) from analysis of the receiver operating characteristic curve. In the non-PALN group, univariate and multivariate analyses for survival were performed on clinicopathological variables. ResultsFrom receiver operating characteristic curve analysis, s-CA19-9 showed good diagnostic accuracy for PALN metastasis (68%; cut-off, 200U/mL) and pN1 (77%; cut-off, 100U/mL). In univariate analysis, age (<65years), s-CA19-9 (100U/mL), portal vein resection, pN1, and positive resection margin (R1) were all identified as significant negative prognostic factors. Five-year survival rates of patients with high s-CA19-9 and pN1 were 6.9% and 7.3%, respectively. In multivariate analysis, high s-CA19-9 and R1 represented independent predictors of poor prognosis. ConclusionsPreoperative s-CA19-9 appears useful as a biomarker in patients with ICC, for predicting not only lymph node metastasis but also prognosis after surgical resection with curative intent.