Impact of L-type amino acid transporter 1 on intrahepatic cholangiocarcinoma

Background : Amino acid transporters, such as L-type amino acid transporter 1 (LAT1), have an effect on tumor growth, metastasis, and survival of various solid tumors. However, the role of LAT1 in patients with intrahepatic cholangiocarcinoma (IHCC) remains unknown. Methods : Forty-six patients who had undergone initial hepatic resection for IHCC at Tokushima University Hospital were enrolled in this study. Immunohistochemical analysis of LAT1 and phosphorylated Akt (p-AKT) was performed using resected specimens. Clinicopathological factors, including prognosis, were analyzed between LAT1-high and LAT1-low groups. Results : The LAT1-high group showed a higher proportion of periductal infiltrating type and higher carcinoembryonic antigen/carbohydrate antigen 19-9 levels compared with the LAT1-low group. Multivariate analysis revealed that LAT1-high expression was an independent prognostic factor for disease-free survival. Furthermore, the proportion of p-AKT positivity was higher in the LAT1-high group than in the LAT1-low group. Conclusions : LAT1 expression was associated with poor prognosis of IHCC and higher p-Akt expression.