Evaluation of Osteopontin (OPN) plasma levels in patients with hepatocellular carcinoma (HCC)

Background and Aims: Osteopontin (OPN) plasma levels have been suggested as a novel biomarker for hepatocellular carcinoma (HCC) (Kim et al., Am J Gastroenterol 2006; 101:2051–9). In the present study, the diagnostic accuracy of OPN was prospectively evaluated in a cohort of HCC patients with various tumor stages and cirrhotic controls and compared with that of alpha-fetoprotein (AFP), tissue polypeptide specific antigen (TPS) and tissue polypeptide antigen (TPA).

Methods: Consecutive treatment-naïve patients with HCC enrolled between 2007 and 2009 (n=52) and age- and sex-matched cirrhotic controls (n=25) were investigated. OPN plasma levels were determined by ELISA (R&D Systems, Minneapolis, MN), AFP serum levels by chemiluminescence immunoassay, and TPS and TPA serum levels by radioimmunoassay (IDL Biotech, Bromma, Sweden, and Dia-Sorin, Saluggia, Italy, respectively). Tumor stage was classified by the Barcelona Clinic Liver Cancer (BCLC) or the UICC staging system. Diagnostic accuracy of tumor markers was assessed by ROC analysis and group means were compared by ANOVA. Results: Compared to cirrhotic controls, AFP was elevated in both early and advanced HCC, OPN was elevated only in advanced HCC while neither TPS nor TPA showed any significant differences (Table). ROC analysis revealed superior diagnostic accuracy of ln(AFP) compared to OPN for diagnosis of HCC (AUROC 0.85 vs. 0.67). Conclusions: OPN is elevated in plasma in advanced stages of HCC but its diagnostic accuracy is inferior to that of AFP.

MeansSD; * p<0.05 vs. cirrhosis
	N	ln(AFP [ng/ml])	OPN [ng/ml]	TPS [U/l]	TPA [U/l]
Cirrhosis	25	153.058	126118	5531130	182246
BCLC A/B	32	4.002.67*	13790	6241884	202502
BCLC C/D	20	6.983.43*	411422*	587553	176126
UICC I-III	34	4.292.91*	172132	381447	133139
UICC IV	18	6.773.45*	392473*	10432475	296631