Value of serum lentil affinity of alpha-fetoprotein in the diagnosis of hepatocellular carcinoma on top of liver cirrhosis

ABSTRACT

Hepatocellular carcinoma [HCC] is a common complication in patients with liver cirrhosis [LC]. Detection of HCC at an early stage is critical for a favorable clinical outcome. AFP-L3% is an isoform of AFP which is very specific for HCC. The AFP-L3% is the percentage of AFP-L3 over the total AFP level. The study aimed to evaluate the utility of AFPL-3% in detection of HCC developing on top of liver cirrhosis, to compare the levels of both alpha- fetoprotein [AFP] and AFP-L3% in HCC versus LC patients without HCC and to define the cut-off level of each tumor marker with the best sensitivity and specificity for HCC detection. The study was conducted on 25 cases of HCC that developed on top of LC and 25 LC cases with no evidence of HCC, as well as 25 apparently healthy controls. The levels of AFP and AFP-L3% were measured for all cases. Biochemical parameters and viral markers were also tested. Imaging and histopathological evidence of HCC were a prerequisite for inclusion in HCC group. Patients included in the HCC group had total AFP value < 200 ng/ml, which is not a diagnostic level for HCC. Levels of AFP and AFP L-3% were significantly higher in patients with HCC compared to those without HCC [P < 0.01]. Receiver-operating characteristic [ROC] curve analysis indicated that the best cut-off value was 15.4% for AFP-L3% to detect HCC as the sensitivity, specificity, positive predictive value [PPV], negative predictive value [NPV] and accuracy were 79.2%, 100%, 100%, 83.3% and 96.2% respectively. For AFP, the best cut-off in the non diagnostic range was 77.8 ng/ ml as the sensitivity, specificity, PPV, NPV, and accuracy were 75%, 68%, 69.2%, 73.9% and 70.4% respectively, The mean serum level of AFP showed no significant difference [P>0.05] regarding Child Pugh classification, numbers of tumor foci nor rumor size, however, it showed a significant difference [P<0.05] regarding lymph nodes invasion and TNM classification in HCC patients. Meanwhile, AFP-L3% showed no significant difference [P>0.05] regarding all these parameters. There was a positive significant correlation [P<0.05] between AFP and both AST and ALT, while AFP-L3% showed inverse significant correlation [P<0.05] with PC%. No significant correlation [P>0.05] was observed between serum AFP and serum AFP-L3% in HCC patients. In patients with total AFP values <200 ng/ml who present a diagnostic dilemma, AFP-L3% had higher sensitivity, specificity, PPV, NPV and accuracy for HCC detection, and was not elevated in any of the patients without HCC with specificity of 100%