Prognostic impact of RPL15 overexpression in intrahepatic cholangiocarcinoma: a marker of aggressive tumor behavior.

BACKGROUND: Overexpression of ribosomal proteins has been found in several cancer types and has an important role in cell proliferation and tumorigenesis. Analysis of the expression profiles of cholangiocarcinoma revealed that ribosomal protein L15 (RPL15) was significantly upregulated in cancer tissues compared to surrounding liver and biliary tissues. Thus, we tried to investigate the role of RPL15 in intrahepatic cholangiocarcinoma. METHODS: The expression of RPL15 in intrahepatic cholangiocarcinoma was assessed using immunohistochemistry. The relationships between RPL15 expression levels and clinicopathological parameters were analyzed, along with investigating its prognostic significance in overall survival (OS), disease-specific survival (DSS), local recurrence-free survival (LRFS) and metastasis-free survival (MeFS). RESULTS: In the cohort comprising 182 patients with intrahepatic cholangiocarcinoma, high expression of RPL15 was significantly associated with advanced tumor (pT) stage (P = 0.005) and high histological grade (P = 0.018). In univariate analyses, overexpression of RPL15 predicted worse DSS (P = 0.0001), LRFS (P < 0.0001) and MeFS (P < 0.0001), but not OS (P = 0.3960). Multivariate analyses revealed that RPL15 overexpression independently predicted worse DSS (P = 0.039), LRFS (P < 0.001) and MeFS (P < 0.001). CONCLUSIONS: Overexpression of RPL15 was identified as an adverse prognostic factor predicting worse outcomes in intrahepatic cholangiocarcinoma. RPL15 could serve as a potential therapeutic target to aid in developing new treatment strategies.