Circulating biomarkers in hepatocellular carcinoma.

Purpose: Our aims are to determine levels of circulating cellular and protein biomarkers in hepatocellular carcinoma (HCC) patients and to analyse any relationships with clinical parameters. Methods: Fifty-four consenting patients were recruited. Circulating tumour cells (CTCs) were enumerated (by CellSearch) and characterised via filtration [by isolation by size of epithelial tumour cells (ISET)] with downstream immunohistochemistry (IHC). Glypican-3 (GPC3) expression in tumour biopsies and CTCs (by IHC) was compared, and levels of circulating caspase-cleaved and full-length cytokeratin 18 (CK18, measured using M30 and M65 ELISAs) were examined as a putative prognostic factor and marker of tumour burden. Results: CTCs were identified in 14 out of 50 (28 %) patients by CellSearch and in 19 out of 19 (100 %) patients by ISET. The presence of GPC3-positive CTCs by ISET was 100 % concordant with the presence of GPC3-positive cells in the original tumour ( n = 5). No statistically significant correlations were observed between CTC number and clinical characteristics, although trends were noted between CTC subtypes, Child-Pugh score and tumour node metastasis stage. Serum M30 and M65 levels (as continuous variables) significantly correlated with overall survival (OS) in a univariate analysis ( p = 0.003 and p < 0.001, respectively); M65 levels remained statistically significant in a multivariate analysis ( p = 0.029). Conclusions: This is the first study to detect GPC3-positive CTCs in HCC, important for drug development with this target. The significant association of circulating CK18 with OS in HCC further exemplifies the utility of circulating biomarkers in cancer. [ABSTRACT FROM AUTHOR]