We aimed to examine the predictive value of changes in perioperative carbohydrate antigen (CA) 19-9 levels for patients operated for perihilar cholangiocarcinoma (pCCA). A total of 322 patients who underwent curative resection for pCCA were divided into three groups: normal preoperative CA19-9 (CA19-9 ≤ 37 U/mL), normalization (preoperative CA19-9 > 37 U/mL, postoperative CA19-9 ≤ 37 U/mL), and non-normalization (pre- and postoperative CA19-9 > 37 U/mL) groups. The association of clinicopathological factors with overall survival (OS) was investigated. The non-normalization group (n = 82) demonstrated significantly worse OS than the normal CA19-9 (n = 114) and normalization (n = 126) groups (5-year OS, 16.9%, 29.4%, and 34.4%, respectively; both p ≤ 0.001). The cutoff points of 300 U/mL for preoperative (p = 0.001) and 37 U/mL for postoperative (p < 0.001) CA19-9 levels showed the strongest prognostic values. In the non-normalization group, patients who underwent R1 resection displayed significantly worse OS than those who underwent R0 resection (median OS, 10.2 vs. 15.7 months; p = 0.016). Multivariate analysis revealed that lymph node metastasis (hazard ratio (HR), 2.07; p < 0.001), postoperative CA19-9 > 37 U/mL (HR, 1.94; p < 0.001), transfusion (HR, 1.74; p = 0.002), and T stage (T3,4) (HR, 1.67; p = 0.006) were related to worse OS. Persistent high CA19-9 level after resection of pCCA and R1 resection, especially in the non-normalization group, was associated with poor OS. A high postoperative CA19-9 level was an independent prognostic factor in resected pCCA.
Keywords: CA19-9; perihilar cholangiocarcinoma; prognosis; tumor marker.