Modeling the time-related fluctuations of AFP and PIVKA-II serum levels in patients with cirrhosis undergoing surveillance for hepatocellular carcinoma
G. Ricco, Chiara Cosma, Giorgio Bedogni, Alessandra Biasiolo, Maria Guarino, Patrizia Pontisso, Filomena Morisco, Filippo Oliveri, D. Cavallone, Ferruccio Bonino, Mario Plebani, Maurizia Rossana Brunetto
Abstract
BACKGROUND: The time-related variability of HCC biomarkers has not been investigated so far. OBJECTIVE: To assess the changes of alpha-fetoprotein (AFP) and protein induced by vitamin-K absence/antagonist-II (PIVKA-II) in patients with HCC (HCC+) as compared to patients without HCC (HCC-). METHODS: AFP and PIVKA-II were measured by a single laboratory using an automated chemiluminescent-enzyme-immunoassay (Fujirebio Inc., Tokyo, Japan) in 1163 sera of 418 cirrhotics (31.1% HBV, 58.6% HCV, 10.3% non-viral etiology) undergoing ultrasound HCC surveillance. The mean (range) number of effective time-points available for analysis was 2.8 (2.0 to 3.0); 124 patients with HCC were matched with 294 who remained HCC free for at least 12 months after the last specimen. AFP and PIVKA-II changes were estimated over time by means of a random-effect generalized least squares (RE-GLS) regression model under the missingness at random assumption. RESULTS: Patients with and without HCC had comparable chronic liver disease etiology and staging. AFP/PIVKA-II median (25th; 75th percentile) values at the latest time-point were 4.2 (2.6; 8.6) ng/mL/32 (25; 42) mAU/mL in HCC- and 8.4 (4.4; 32.1) ng/mL/66 (32; 192) mAU/mL in HCC+ (p< 0.001). Log10AFP and log10PIVKA-II time-changes differed in HCC+ and HCC- patients. In HCC+ patients, both log10AFP and log10PIVKA-II showed an increasing trend over time. In HCC- patients, log10PIVKA-II variations were minimal as compared to log10AFP variations. The percent increase of log10AFP at 6 months vs. baseline was 11% (95%CI 5 to 17%) and 5% (95%CI 1 to 8%) for log10PIVKA-II in HCC+vs. HCC- patients. CONCLUSIONS: The present retrospective study of the biological variability of AFP and PIVKA-II suggests that their time-related changes may serve as potential predictors of HCC. This topic needs to be addressed by longitudinal studies.