106P - Clinicopathologic and prognostic significance of FBXL5 expression in hepatocellular carcinoma

Background

The deficiency of F-Box and leucine rich repeat protein 5 (FBXL5), an iron-sensing ubiquitin ligase, triggers carcinogenesis of hepatocellular carcinoma (HCC) due to iron overload. However, the expression of FBXL5 and its clinical implication have not been elucidated in HCC.

Methods

We investigated FBXL5 protein expression using immunohistochemistry in HCC tissue samples of two institutes, Samsung Medical Center and Hallym University Sacred Heart Hospital. X-tile software was used for the optimization of cut-off value. We evaluated the association between FBXL5 expression and various clinicopathological parameters. For external validation, The Cancer Genome Atlas (TCGA) cohort was used.

Results

Expression of FBXL5 less than 5% of tumor was designated as low expression group and the remaining referred as high expression group. Low FBXL5 expression was found in 78 cases out of 395 cases (19.7%) and associated with non-viral etiology (P = 0.024). Low FBXL5 expression group showed inferior disease-specific overall survival (OS; P = 0.013) and recurrence free survival (RFS; P=0.005) compared to high FBXL5 expression group. Similar to our cohort, cases with low FBLX5 mRNA level showed inferior OS and RFS (P<0.001 and P=0.002, respectively) than those with high FBLX5 mRNA level in TCGA cohort.

Conclusions

Low expression of FBXL5 is associated with non-viral HCC patients and associated with inferior disease-specific OS and RFS. FBXL5 can be used as a potential prognostic markers and therapeutic target for non-viral HCC.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.