Double-Negative α-Fetoprotein and Carbohydrate Antigen 19-9 Predict a Good Prognosis in Intrahepatic Cholangiocarcinoma: A Propensity Score Matching Analysis.

INTRODUCTION Carbohydrate antigen 19-9 (CA19-9) and α-fetoprotein (AFP) are routinely tested in patients with liver malignancies before surgery. However, few reports have explored the relevance of the expression pattern of these 2 tumor markers regarding the prognosis of intrahepatic cholangiocarcinoma (ICC). We herein combined these 2 tumor markers to investigate the influence on ICC malignancy and patient prognosis. METHODS From March 2009 to December 2019, 519 consecutive patients with newly diagnosed ICC who underwent R0 resection were enrolled and followed. The relationships between clinicopathological parameters and these 2 tumor markers were analyzed. Propensity score matching was used to eliminate the baseline differences. RESULTS A lower proportion of patients with double-negative AFP and CA19-9 had advanced tumor-node-metastasis stage, larger tumor diameter, multiple tumors, lymph node metastasis, microvascular invasion, and perineural invasion. With propensity score matching, patients were divided into double-negative and non-double-negative groups, with 128 patients in each group, and the 5-year recurrence-free survival and overall survival rates were 33.8 vs 15.2 (P < 0.001) and 45.3 vs 19.0, respectively (P < 0.001). In the multivariate Cox analyses, double negativity for the 2 tumor markers was an independent factor for recurrence-free survival (hazard ratios, 0.578; 95% CI, 0.442-0.755, P < 0.001) and overall survival (hazard ratios, 0.567; 95% CI, 0.434-0.741, P < 0.001). DISCUSSION Double negativity for CA19-9 and AFP indicated less invasive tumor characteristics in patients with ICC. Patients with double-negative tumor markers achieved better outcomes than those with non-double-negative markers, which is meaningful for prognostic counseling and therapeutic triage.