Singapore study highlights differences between HBV-related and cryptogenic HCC
The patient profiles of individuals diagnosed with hepatocellular carcinoma (HCC) vary depending on whether the cause of HCC is hepatitis B virus (HBV) infection or cryptogenic, a Singapore study found.
Researchers identified 1,292 patients with HCC from the database of the Department of Gastroenterology and Hepatology at Singapore General Hospital, in place since 1980. Of these, 916 cases were attributed to HBV (70.9 percent), while 163 were cryptogenic (12.6 percent). HCC cases were classified as cryptogenic if negative for HBsAg*, HBcAb**, or anti-hepatitis C virus antibody, in the presence of fat infiltration of the liver based on ultrasonography, computed tomography, or magnetic resonance imaging, no significant history of alcohol consumption (<20 g alcohol/day), or after excluding other liver diseases.
The ratio of cryptogenic to HBV-related HCC changed over time, increasing from 1:6.7 between 1980 and 2005 to 1:3.9 between 2006 and 2015. [Dig Dis Sci 2018;doi:10.1007/s10620-018-5331-x]
Compared with patients with HBV-related HCC, those with cryptogenic HCC tended to be older (mean age at diagnosis, 67.6 vs 59.4 years; p<0.001), and were less likely to be male (69.9 percent vs 83.8 percent; p<0.001) or smokers (25.8 percent vs 32.2 percent; p=0.008).
Patients with HBV-related HCC had higher alanine transaminase (60.9 vs 48.0 U/L; p=0.003), haemoglobin (12.7 vs 12.0 g/dL; p<0.001), and albumin levels (32.9 vs 31.3 g/L; p=0.007), as well as longer prothrombin time (13.2 vs 12.7 s; p=0.023) than those with cryptogenic HCC.
Patients with cryptogenic HCC were also more likely to present with unifocal HCC than those with HBV-related HCC (55.2 percent vs 46.5 percent; p=0.002) and Child-Pugh scores were higher in patients with cryptogenic- compared with HBV-related HCC (7.4 vs 7.0; p=0.039). However, surgical resection rates were comparable between patients with HBV and cryptogenic HCC (23.5 percent vs 17.9 percent; p=0.202), as was the incidence of portal vein involvement (33.7 percent vs 34.4 percent; p=0.955) and survival rates (p=0.367).
“In Asia, chronic HBV infection accounts for the majority of [HCC] cases, but non-viral or nonalcoholic steatohepatitis (NASH) aetiologies may play an increasingly prominent role in line with current socioeconomic improvements resulting in a rising incidence of lifestyle-related disorders,” said the researchers.
“Our study found that the prevalence of cryptogenic HCC is on a significantly rising trend with an increase in the proportion of cryptogenic HCC, as compared to HBV-related HCC over the past decade. Temporal trends suggest that HCC attributed to HBV may be on the decline, while cryptogenic- or NASH-related HCC is an emerging clinical entity,” they said.
The nationwide implementation of HBV immunization as well as a reduction in the number of migrants from China could be among the reasons for the decrease in proportion of HBV-related HCC cases. Conversely, the increase in the incidence of nonalcoholic fatty liver disease (NAFLD) may contribute to the rise in cryptogenic-related HCC cases, they added.
“Understanding these changing epidemiologic trends will assist the relevant authorities and clinicians in planning for future public health policies and adequate resource allocation,” noted the researchers. These should include implementing cost-effective surveillance programmes to detect HCC in patients without cirrhosis, screening patients at high risk of HCC, and preventing obesity, diabetes, and NAFLD, the latter being “the best long-term strategy in battling the rising prevalence of cryptogenic HCC”, they said.