Hepatocellular carcinoma risk scores: ready to use in 2015?

Epidemiology of Virus Infection and Human Cancer

Seven viruses including the Epstein-Barr virus (EBV), hepatitis B virus (HBV), hepatitis C virus (HCV), Kaposi's sarcoma herpes virus (KSHV), human immunodeficiency virus, type-1 (HIV-1), human T cell lymphotrophic virus, type-1 (HTLV-1), and human papillomavirus (HPV) have been classified as Group 1 human carcinogens by the International Agency for Research on Cancer (IARC). The conclusions are based on the findings of epidemiological and mechanistic studies. EBV, HPV, HTLV-1, and KSHV are direct carcinogens; HBV and HCV are indirect carcinogens through chronic inflammation; and HIV-1 is an indirect carcinogen through immune suppression. Some viruses may cause more than one cancer, while some cancers may be caused by more than one virus. However, only a proportion of persons infected by these oncogenic viruses will develop specific cancers. A series of studies have been carried out to assess the viral, host, and environmental cofactors of EBV-associated nasopharyngeal carcinoma, HBV/HCV-associated hepatocellular carcinoma, and HPV-associated cervical carcinoma. Persistent infection, high viral load, and viral genotype are important risk predictors of these virus-caused cancers. Risk calculators incorporating host and viral risk predictors have been developed for the prediction of long-term risk of hepatocellular carcinoma, nasopharyngeal carcinoma and cervical cancer. These risk calculators are useful for the triage and clinical management of infected patients. Both clinical trials and national programs of immunization, antiviral therapy and screening have demonstrated a significant reduction in the incidence of cancers caused by HBV, HCV, and HPV. Future research on gene-gene and gene-environment interactions of oncogenic viruses and the human host using large-scale longitudinal studies with serial measurements of biosignatures are in urgent need.

Plasma DNA methylation marker and hepatocellular carcinoma risk prediction model for the general population

Metastases in the later stages of hepatocellular carcinoma (HCC) cause the majority of deaths associated with the disease, making early detection crucial to patient survival. Risk models assessing HCC risk in the general population can be used for risk stratification for further HCC surveillance, however, none have been validated externally. Methylation of circulating DNA shows potential for non-invasive diagnosis of HCC. We conducted a prospective case-control study nested within a community-based cohort. We measured methylation levels in six genes (CDKN2A, RASSF1A, STEAP4, TBX2, VIM and ZNF154) which were identified in our previous work, using pre-diagnostic plasma DNA from 237 HCC cases and 257 matched controls. We found TBX2 hypermethylation was associated with increased HCC risk, with ORs (95% CI) of 3.2 (1.8-6.0). The associations were mainly among high-risk subjects; among subjects infected with HBV/HCV, the OR (95% CI) of TBX2 methylation was 5.3 (2.2-12.7). Among subjects with high risk scores, the ORs (95% CIs) were 7.8 (1.5-38.6) for Wen-HCC model ≥16, 5.8 (2.2-15.5) for Hung-HCC ≥15 and 7.5 (2.2-26.0) for Michikawa-HCC ≥8. Adding TBX2 methylation improved the accuracy of risk models for a high-risk population, with the area under the curve (AUC) of 76% for Wen-HCC score with TBX2 methylation compared with 69% with Wen-HCC alone. The AUCs were 63% for Hung-HCC score plus TBX2 methylation, and 53% for Hung-HCC alone, 65% for Michikawa-HCC score plus TBX2 methylation and 58% for Michikawa-HCC alone. Our findings suggest the potential increase in risk assessment discrimination and accuracy from incorporation of DNA methylation.

Risk and predictors of hepatocellular carcinoma for chronic hepatitis B patients with newly developed cirrhosis

BACKGROUND AND AIMS

Most studies on risk predictors of hepatocellular carcinoma (HCC) among cirrhotic chronic hepatitis B patients do not confirm the date at cirrhosis diagnosis. We examined HCC risk and predictors in chronic hepatitis B patients with newly diagnosed cirrhosis.

METHODS

4155 HBsAg seropositive participants were followed every 6-12 months with seromarker testing. Cirrhosis was ascertained through abdominal ultrasonography and computerized linkage with national health insurance profiles. Predictors included in Cox proportional hazards models were age, HBeAg serostatus, serum levels of HBsAg, alanine aminotransferase (ALT), alpha-fetoprotein (AFP), and ALDH2 rs671 genotypes.

RESULTS

A total of 301 patients developed cirrhosis, 76 of whom later developed HCC after 2462 person-years, showing an average annual incidence of 3.1%. The 15-year cumulative HCC risk among cirrhotics was 39.8% with a lifetime (30-80 years old) HCC risk of 78.5%. The adjusted HR's (95% CI, P-value) were 14.26 (3.17-64.08, P = 0.0005) for age at cirrhosis diagnosis of ≥60 years (vs 30-39 years), 2.85 (1.49-5.46, P = 0.0015) for HBeAg seropositivity (vs HBeAg seronegativity with HBsAg levels <1000 IU/mL), 0.35 (0.20-0.59, P < 0.0001) for AA/AG genotypes of rs671 (vs GG genotype), 3.68 (1.70-7.99, P = 0.0010) for ALT levels >45 U/L (vs <15 U/L), 3.52 (1.78-6.93, P = 0.0003) for AFP levels >20 ng/mL (vs <10 ng/mL), and 2.64 (1.38-5.07, P = 0.0035) for HBsAg levels ≥1000 IU/mL (vs <1000 IU/mL among HBeAg seronegatives).

CONCLUSIONS

Older age, GG genotype of ALDH2 rs671, HBeAg seropositivity, and elevated serum levels of ALT, AFP, and HBsAg at cirrhosis diagnosis were HCC risk predictors in cirrhotic chronic hepatitis B patients.