FIB-4 index identifies chronic HBV patients with lowest HCC risk
medwireNews: The noninvasive fibrosis-4 (FIB-4) index can further refine the existing favorable clinical profile for hepatocellular carcinoma (HCC) risk in noncirrhotic patients with chronic hepatitis B virus (HBV) infection and help identify those with the lowest risk, say researchers.
They explain that the current definitions – of varying stringency – of a favorable profile are based on biochemical and viral factors, including the levels of alanine aminotransferase (ALT) and HBV DNA, low values of which signify low-replicative HBV infection, which is associated with a reduced HCC risk.
However, the severity of liver fibrosis has recently been proposed as an HCC risk factor, which is why the study authors investigated whether the FIB-4 index – a surrogate biomarker of liver fibrosis – could further improve HCC risk prediction.
The current analysis included 2075 treatment-naïve chronic HBV patients without cirrhosis at baseline, drawn from the Taiwanese ERADICATE-B study, of whom 137 developed HCC over a median follow-up of 15.38 years.
Multiple statistical analyses confirmed a FIB-4 score of 1.29 as the best cutoff value, such that patients with a baseline score equal to or above this value had a significantly increased risk for HCC versus those with lower values, at a hazard ratio of 2.27 after adjusting for factors such as age, sex, HBV DNA levels, and platelet count (p<0.01).
Combining the FIB-4 index with the three currently used definitions of low-replicative infection stratified HCC risk in all cases, report Jia-Horng Kao, from the National Taiwan University College of Medicine in Taipei, and colleagues.
For instance, the index was applied to the 408 participants who met the most stringent criteria, that is, absence of hepatitis B e antigen, HBV DNA levels below 2000 IU/mL, and ALT levels under 40 U/L, as well as baseline hepatitis B surface antigen levels below 1000 IU/mL. None of the 326 patients who also had a FIB-4 score of less than 1.29 developed HCC during a median of 15.56 years. By contrast, those with a higher FIB-4 index had an annual cumulative HCC incidence of 0.22%.
Kao et al validated their findings in an independent cohort of 532 noncirrhotic patients with sustained viral suppression as a result of long-term nucleos(t)ide analog treatment, among whom there were 10 cases of HCC during a median treatment period of 6.58 years.
In this cohort, FIB-4 scores of at least 1.29 at baseline and after a year of treatment were associated with a significantly increased cumulative incidence of HCC (p=0.023 and <0.001, respectively), whereas none of the participants with scores below the cutoff developed HCC during follow-up.
The study authors write in The American Journal of Gastroenterology that “[i]mplementation of HCC surveillance is important because it is the only way to identify HCC at an early stage, which reduces disease-related morbidity and mortality.”
But as it can be costly, it is important to identify individuals who may not derive additional benefit from surveillance, and they believe these findings could be useful for physicians to help pinpoint patients with the lowest risk for HCC.
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