Early-onset Hepatocellular Carcinoma Research Articles

Clinical Characteristics and Prognosis of Early-Onset Hepatocellular Carcinoma: A Retrospective Cohort Study Based on Population Data.

The incidence of young patients diagnosed with hepatocellular carcinoma (HCC) is projected to rise. This study aimed to investigate the distinctive characteristics of adolescent and young adult (AYA) patients with HCC and identify the risk factors that impact their survival. This study included 1005 AYA patients and 55,435 older adult (OA) patients with HCC, using data from the Surveillance, Epidemiology, and End Results database. Propensity score matching was used to adjust for baseline differences in patient characteristics. The Kaplan-Meier curve and log-rank test are utilized to compare the overall survival between the two groups. The Cox proportional hazards regression model was used for subgroup analysis to identify risk factors for overall survival in AYA patients. AYA patients exhibited a higher proportion of advanced clinical stage (49.15% vs 37.57%, P < 0.001) and fibrolamellar hepatocellular carcinoma (14.13% vs 0.09%, P < 0.001), but a lower incidence of alpha-fetoprotein positivity (32.04% vs 45.32%, P < 0.001) and cirrhosis (8.86% vs 18.32%, P < 0.001). The subgroup analysis results indicated that AYA patients had a more favorable prognosis than OA patients in most subgroups. Undifferentiated carcinoma emerged as the predominant risk factor for AYA patients (Hazard Ratio [HR], 6.08 [2.53-14.62]), whereas partial hepatectomy was determined to be the most advantageous factor (HR, 0.29 [0.23-0.37]). AYA patients with HCC exhibit more aggressive characteristics but demonstrate a better prognosis compared to the OA group, necessitating personalized surveillance and treatment.

Comparison of metastasis and prognosis between early-onset and late-onset hepatocellular carcinoma: A population-based study

BackgroundWhile hepatocellular carcinoma (HCC) represents a highly heterogeneous disease with variable oncogenesis mechanisms and biological features, little is understood about differences in distant metastasis (DM) and prognosis between early-onset and late-onset HCC. This study defined early-onset disease as cancer diagnosed at age younger than 50 years and aimed to present a comprehensive analysis to characterize these disparities based on age. MethodsInformation of HCC patients was retrospectively collected from the SEER database and our hospital. Patient demographics, tumor characteristics, and survival were compared between the two groups. A 1:1 propensity score matching (PSM) was adopted to adjust confounding factors. Logistic and cox analysis were utilized to explore risk factors of DM and prognosis, respectively. Besides, the survival differences were assessed by the Kaplan–Meier curve and log-rank test. ResultsIn total, 19187 HCC patients obtained from the SEER database and 129 HCC patients obtained from our own center were enrolled. Among 19187 patients with HCC, 3376 were identified in the matched cohort, including 1688 early-onset patients and 1688 late-onset patients. Compared with late-onset HCC, early-onset HCC was more likely to occur in female (25.2% vs. 22.9%, P = 0.030), have large tumors (>10.0 cm, 24.1% vs. 14.6%, P = 0.000), harbor poorly differentiated/undifferentiated cancers (17.0% vs. 14.0%, P = 0.003), present advanced clinical stage (T3+T4, 33.7% vs. 28.5%; N1, 9.2% vs. 6.7%; P = 0.000), and develop DM (13.0% vs. 9.5%, P = 0.000). After adjustment for confounders by PSM, we discovered that early-onset HCC remained an independent risk factor for DM. However, combined with Kaplan–Meier curve and cox analysis, early-onset HCC was an independent favorable predictor of survival. We validated these data on an independent cohort from our hospital. ConclusionIn this population-based study, despite developing DM more frequently, early-onset HCC exhibited a superior prognosis than late-onset HCC. Nevertheless, further research is warranted to understand the underlying aetiologic basis for the disparities.

Construction of a Nomogram to Predict Overall Survival in Patients with Early-Onset Hepatocellular Carcinoma: A Retrospective Cohort Study.

Hepatocellular carcinoma (HCC) is a widespread and impactful cancer which has pertinent implications worldwide. Although most cases of HCC are typically diagnosed in individuals aged ≥60 years, there has been a notable rise in the occurrence of HCC among younger patients. However, there is a scarcity of precise prognostic models available for predicting outcomes in these younger patients. A retrospective analysis was conducted to investigate early-onset hepatocellular carcinoma (EO-LIHC) using data from the Surveillance, Epidemiology, and End Results (SEER) database from 2004 to 2018. The analysis included 1392 patients from the SEER database and our hospital. Among them, 1287 patients from the SEER database were assigned to the training cohort (n = 899) and validation cohort 1 (n = 388), while 105 patients from our hospital were assigned to validation cohort 2. A Cox regression analysis showed that age, sex, AFP, grade, stage, tumor size, surgery, and chemotherapy were independent risk factors. The nomogram developed in this study demonstrated its discriminatory ability to predict the 1-, 3-, and 5-year overall survival (OS) rates in EO-LIHC patients based on individual characteristics. Additionally, a web-based OS prediction model specifically tailored for EO-LIHC patients was created and validated. Overall, these advancements contribute to improved decision-making and personalized care for individuals with EO-LIHC.

Functional analyses of single nucleotide polymorphic variants of the DNA glycosylase NEIL1 in sub-Saharan African populations

Nei-like glycosylase 1 (NEIL1) is a DNA repair enzyme that initiates the base excision repair (BER) pathway to cleanse the human genome of damage. The substrate specificity of NEIL1 includes several common base modifications formed under oxidative stress conditions, as well as the imidazole ring open adducts that are induced by alkylating agents following initial modification at N7 guanine. An example of the latter is the persistent and mutagenic 8,9-dihydro-8-(2,6-diamino-4-oxo-3,4-dihydropyrimid-5-yl-formamido)-9-hydroxyaflatoxin B1 (AFB1-FapyGua) adduct, resulting from the alkylating agent aflatoxin B1 (AFB1) exo-8–9-epoxide. Naturally occurring single nucleotide polymorphic (SNP) variants of NEIL1 are hypothesized to be associated with an increased risk for development of early-onset hepatocellular carcinoma (HCC), especially in environments with high exposures to aflatoxins and chronic inflammation from viral infections and alcohol consumption. Given that AFB1 exposures and hepatitis B viral (HBV) infections represent a major problem in the developing countries of sub-Saharan Africa, it is pertinent to study SNP NEIL1 variants that are present in this geographic region. In this investigation, we characterized the three most common NEIL1 variants found in this region: P321A, R323G, and I182M. Biochemical analyses were conducted to determine the proficiencies of these variants in initiating the repair of DNA lesions. Our data show that damage recognition and excision activities of P321A and R323G were near that of wild-type (WT) NEIL1 for both thymine glycol (ThyGly) and AFB1-FapyGua. The substrate specificities of these variants with respect to various oxidatively-induced base lesions were also similar to that of WT. In contrast, the I182M variant was unstable, such that it precipitated under a variety of conditions and underwent rapid inactivation at a biologically relevant temperature, with partial stabilization being observed in the presence of undamaged DNA. This study provides insight regarding the potential increased risk for early-onset HCC in human populations carrying the NEIL1 I182M variant.

Socioeconomic Factors Affect Age of Onset of Hepatocellular Carcinoma

INTRODUCTION: Hepatocellular carcinoma (HCC) is an aggressive malignancy with a heterogeneous disease process and variable clinical presentation. Patient outcomes vary based on differential tumor biology, demographics, clinicopathologic variables, hospital-system and treatment-related factors. Our study aimed to investigate the socioeconomic factors associated with early-onset HCC. METHODS: We queried the Surveillance, Epidemiology, and End Results (SEER) database for adult patients with HCC from 2007 to 2016. Clinicopathologic data were correlated to factors associated with age at diagnosis. Logistic regression with univariate/multivariate linear regression was performed to determine factors associated with early-onset HCC. RESULTS: Overall, 36,982 patients were identified in the database. There were significant differences between the 2 patient cohorts. There were a disproportionate number of racial/ethnic minorities diagnosed with early-onset HCC (p < 0.05). Early-onset HCC patients were more likely to be uninsured or have Medicaid insurance (p < 0.05) and have lower education levels (p < 0.05). Early-onset HCC also presented at advanced stages (stage III). Early-onset HCC was more likely to undergo upfront resection compared with late-onset group (p < 0.05). Socioeconomic factors such as race/ethnicity, insurance, and education level were associated with age of HCC onset. CONCLUSION: Socioeconomic factors affect the age of HCC onset. Patients of lower socioeconomic status (SES) are more likely to present with early-onset HCC (age <45). HCC disproportionately affects disadvantaged patients. Lower SES patients are more likely to receive hepatic resection or definitive chemotherapy compared to higher SES patients who are more likely to receive targeted local-regional therapy. Identifying specific socioeconomic disparities can lead to more targeted screening programs for high-risk individuals to improve HCC treatment outcomes.

Hepatocellular carcinoma in Hepatitis B and Human Immunodeficiency Virus coinfection in Africa: a focus on surveillance.

Human immunodeficiency virus (HIV) and hepatitis-B virus (HBV) infections are weighty public health challenges, especially in the African continent. The direct carcinogenic effect of HBV means that it remains a potent cause of early-onset hepatocellular carcinoma (HCC) in Sub-Saharan Africa (SSA), where it causes significant morbidity and mortality. The presence of HIV infection in HBV-infected patients poses a complicating factor, as coinfection has been shown to hasten the progression of liver disease to cirrhosis and HCC, and often resulting in early-age hepatocarcinogenesis with consequent late diagnosis and lower survival. In this review, we discuss this unique conundrum, the epidemiology of HIV-HBV coinfection in SSA, its effect on liver disease and development of HCC, as well as practices and barriers to HCC surveillance in this distinct population. We propose a way forward to curb this considerable health burden focusing on reduction of disease stigma, the need for easy-to-measure biomarkers, and implementation of large prospective studies in this population.

DNA polymerases η and κ bypass N2-guanine-O6-alkylguanine DNA alkyltransferase cross-linked DNA-peptides

DNA-protein cross-links are formed when proteins become covalently trapped with DNA in the presence of exogenous or endogenous alkylating agents. If left unrepaired, they inhibit transcription as well as DNA unwinding during replication and may result in genome instability or even cell death. The DNA repair protein O6-alkylguanine DNA-alkyltransferase (AGT) is known to form DNA cross-links in the presence of the carcinogen 1,2-dibromoethane, resulting in G:C to T:A transversions and other mutations in both bacterial and mammalian cells. We hypothesized that AGT-DNA cross-links would be processed by nuclear proteases to yield peptides small enough to be bypassed by translesion (TLS) polymerases. Here, a 15-mer and a 36-mer peptide from the active site of AGT were cross-linked to the N2 position of guanine via conjugate addition of a thiol containing a peptide dehydroalanine moiety. Bypass studies with DNA polymerases (pols) η and κ indicated that both can accurately bypass the cross-linked DNA peptides. The specificity constant (kcat/Km) for steady-state incorporation of the correct nucleotide dCTP increased by 6-fold with human (h) pol κ and 3-fold with hpol η, with hpol η preferentially inserting nucleotides in the order dC > dG > dA > dT. LC-MS/MS analysis of the extension product also revealed error-free bypass of the cross-linked 15-mer peptide by hpol η. We conclude that a bulky 15-mer AGT peptide cross-linked to the N2 position of guanine can retard polymerization, but that overall fidelity is not compromised because only correct bases are inserted and extended.

Early Life Exposure to Aflatoxin B1 in Rats: Alterations in Lipids, Hormones, and DNA Methylation among the Offspring.

Aflatoxins are toxic compounds produced by molds of the Aspergillus species that contaminate food primarily in tropical countries. The most toxic aflatoxin, aflatoxin B1 (AFB1), is a major cause of hepatocellular carcinoma (HCC) in these countries. In sub-Saharan Africa, aflatoxin contamination is common, and perinatal AFB1 exposure has been linked to the early onset of HCC. Epigenetic programming, including changes to DNA methylation, is one mechanism by which early life exposures can lead to adult disease. This study aims to elucidate whether perinatal AFB1 exposure alters markers of offspring health including weight, lipid, and hormone profiles as well as epigenetic regulation that may later influence cancer risk. Pregnant rats were exposed to two doses of AFB1 (low 0.5 and high 5 mg/kg) before conception, throughout pregnancy, and while weaning and compared to an unexposed group. Offspring from each group were followed to 3 weeks or 3 months of age, and their blood and liver samples were collected. Body weights and lipids were assessed at 3 weeks and 3 months while reproductive, gonadotropic, and thyroid hormones were assessed at 3 months. Prenatal AFB1 (high dose) exposure resulted in significant 16.3%, 31.6%, and 7.5% decreases in weight of the offspring at birth, 3 weeks, and 3 months, respectively. Both doses of exposure altered lipid and hormone profiles. Pyrosequencing was used to quantify percent DNA methylation at tumor suppressor gene Tp53 and growth-regulator H19 in DNA from liver and blood. Results were compared between the control and AFB1 exposure groups in 3-week liver samples and 3-week and 3-month blood samples. Relative to controls, Tp53 DNA methylation in both low- and high-dose exposed rats was significantly decreased in liver samples and increased in the blood (p < 0.05 in linear mixed models). H19 methylation was higher in the liver from low- and high-exposed rats and decreased in 3-month blood samples from the high exposure group (p < 0.05). Further research is warranted to determine whether such hormone, lipid, and epigenetic alterations from AFB1 exposure early in life play a role in the development of early-onset HCC.

Epidemiology of Liver Cancer in Latin America: Current and Future Trends.

Over 38,000 cases of hepatocellular carcinoma (HCC) are estimated to occur in Latin America annually. The region is characterized by sociocultural heterogeneity and economic disparities, which impose barriers in addressing this major health issue. A significant proportion of patients are still diagnosed in the later stages of the disease, although efforts to implement effective screening programs have been reported by referral centers. While viral hepatitis remains the predominant etiology of liver disease among HCC cases in Latin America, a high prevalence of fatty liver disease in the region is a matter of concern, reflecting the current scenario in many Western countries. In addition, other risk factors such as alcohol, aflatoxin, and early-onset HCC in hepatitis B virus infection contribute to the burden of HCC in Latin America. Interventions to increase screening coverage, expand healthcare access, and implement continuing medical training are key challenges to be overcome.

Structural Insight into DNA-Dependent Activation of Human Metalloprotease Spartan

The DNA-dependent metalloprotease Spartan (SPRTN) cleaves DNA-protein crosslinks (DPCs) and protects cells from DPC-induced genome instability. Germline mutations of SPRTN are linked to human Ruijs-Aalfs syndrome (RJALS) characterized by progeria and early-onset hepatocellular carcinoma. The mechanism of DNA-mediated activation of SPRTN is not understood. Here, we report the crystal structure of the human SPRTN SprT domain bound to single-stranded DNA (ssDNA). Our structure reveals a Zn2+-binding sub-domain (ZBD) in SprT that shields its active site located in the metalloprotease sub-domain (MPD). The narrow catalytic groove between MPD and ZBD only permits cleavage of flexible substrates. The ZBD contains an ssDNA-binding site, with a DNA-base-binding pocket formed by aromatic residues. Mutations of ssDNA-binding residues diminish the protease activity of SPRTN. We propose that the ZBD contributes to the ssDNA specificity of SPRTN, restricts the access of globular substrates, and positions DPCs, which may need to be partially unfolded, for optimal cleavage.

Hepatocellular carcinoma among US and non-US-born patients with chronic hepatitis B: Risk factors and age at diagnosis.

BackgroundRisk factors for hepatocellular carcinoma (HCC) have not been well characterized among African immigrants with chronic hepatitis B virus (HBV) infection. We conducted a case-control study to identify demographic and clinical factors associated with HCC among a diverse cohort of patients with chronic HBV infection seen in a large academic health setting.MethodsWe identified a total of 278 patients with HCC and chronic HBV seen at two medical centers in a 14-year span from January 2002 to December 2015. These cases were age- and sex-matched in a 1:3 ratio with 823 non-cancer control subjects with chronic HBV. Conditional logistic regression was used to estimate the odds of HCC by race, with black race stratified by African-born status, after adjusting for diabetes, HIV or HCV coinfection, alcohol misuse and cirrhosis.ResultsOf the 278 HCC cases, 67% were 60 years of age or older, 78% were male, 87% had cirrhosis and 72% were Asian. HIV infection was present in 6% of cases. Only 7% (19 of 278) of HCC cases were black, of whom 14 were African immigrants. The median age at HCC diagnosis was 44 years in Africans. Notably, nearly all (93%) of the African-born patients with HCC were diagnosed at an age younger than 60 years compared with 52% of Asian cases (P<0.001). The main factors independently associated with greater odds of HCC overall were Asian race (adjusted odds ratio [aOR] 3.3, 95% confidence interval [CI] 1.9–5.5) and cirrhosis (aOR 19.7, 95% CI 12.2–31.8).ConclusionAfrican immigrants accounted for a small proportion of HBV-associated HCC cases overall compared with Asians but appeared to have greater likelihood of early-onset HCC. Optimal strategies for HCC prevention in these key subroups with chronic HBV warrant further study.

Molecular characterization of hepatitis B virus (HBV) in African children living in Australia identifies genotypes and variants associated with poor clinical outcome.

Migration from sub-Saharan Africa is contributing to the rising incidence of chronic hepatitis B (CHB) infection and its complications in Australia. African CHB is associated with unique genotypes, such as E and A1, which are associated with reduced vaccine efficacy and early-onset hepatocellular carcinoma, respectively, although the prevalence of these genotypes outside Africa is poorly described. Treatment-naïve children of African origin with CHB were recruited at the Royal Children's Hospital Melbourne. Population-based sequencing of the complete HBV genome, or the clinically relevant basal core promoter (BCP)/precore (PC) region, was performed, and the HBV genotype/subgenotype assigned by phylogenetic analysis. HBV was characterized in serum from 67 children, median age 12.5 years. HBV genotype E was most frequent (70 %), with genotype D [25 %; subgenotypes D6 (formerly D7)/D3/D2)] and subgenotype A1 (5 %) also being identified. Despite their young age, over 50 % of the children were HBeAg-negative and had seroconverted to anti-HBe, with this being associated with canonical BCP/PC mutations in the majority of cases. The profile of HBV in African children living in Australia was characterized by early HBeAg seroconversion and infection with HBV variants associated with poor clinical outcome, as well as genotypes previously associated with reduced vaccine efficacy or rapid progression to liver cancer. These findings have important ramifications for patient monitoring and treatment guidelines in the Australian paediatric setting.

Spartan deficiency causes accumulation of Topoisomerase 1 cleavage complexes and tumorigenesis.

Germline mutations in SPRTN cause Ruijs–Aalfs syndrome (RJALS), a disorder characterized by genome instability, progeria and early onset hepatocellular carcinoma. Spartan, the protein encoded by SPRTN, is a nuclear metalloprotease that is involved in the repair of DNA–protein crosslinks (DPCs). Although Sprtn hypomorphic mice recapitulate key progeroid phenotypes of RJALS, whether this model expressing low amounts of Spartan is prone to DPC repair defects and spontaneous tumors is unknown. Here, we showed that the livers of Sprtn hypomorphic mice accumulate DPCs containing Topoisomerase 1 covalently linked to DNA. Furthermore, these mice exhibited DNA damage, aneuploidy and spontaneous tumorigenesis in the liver. Collectively, these findings provide evidence that partial loss of Spartan impairs DPC repair and tumor suppression.

DNA-dependent protease activity of human Spartan facilitates replication of DNA-protein crosslink-containing DNA.

Mutations in SPARTAN are associated with early onset hepatocellular carcinoma and progeroid features. A regulatory function of Spartan has been implicated in DNA damage tolerance pathways such as translesion synthesis, but the exact function of the protein remained unclear. Here, we reveal the role of human Spartan in facilitating replication of DNA–protein crosslink-containing DNA. We found that purified Spartan has a DNA-dependent protease activity degrading certain proteins bound to DNA. In concert, Spartan is required for direct DPC removal in vivo; we also show that the protease Spartan facilitates repair of formaldehyde-induced DNA–protein crosslinks in later phases of replication using the bromodeoxyuridin (BrdU) comet assay. Moreover, DNA fibre assay indicates that formaldehyde-induced replication stress dramatically decreases the speed of replication fork movement in Spartan-deficient cells, which accumulate in the G2/M cell cycle phase. Finally, epistasis analysis mapped these Spartan functions to the RAD6-RAD18 DNA damage tolerance pathway. Our results reveal that Spartan facilitates replication of DNA–protein crosslink-containing DNA enzymatically, as a protease, which may explain its role in preventing carcinogenesis and aging.

Impact of country of birth on age at the time of diagnosis of hepatocellular carcinoma in the United States.

There is global variation in the onset of hepatocellular carcinoma (HCC). The objective of the current study was to investigate the impact of country of birth on age at the time of HCC diagnosis in the United States. Incident HCC cases diagnosed between 2000 and 2012 in the Surveillance, Epidemiology, and End Results program 18 registry were included. Factors associated with very early onset (age at diagnosis < 40 years) and early onset (age at diagnosis < 50 years) were identified by logistic regression. A total of 59,907 patients were included. The median age at the time of diagnosis of HCC was 62 years and 76% of the patients were male. Of the 75% of patients for whom information regarding birth country was available, 29% were foreign born. In multivariate logistic regression, birth in West Africa (adjusted odds ratio [AOR], 16.3; 95% confidence interval [95% CI], 9.2-27.9 [P<.01]), Central/South/other Africa (AOR, 11.0; 95% CI, 4.5-23.7 [P<.01]), Oceania (AOR, 4.9; 95% CI, 2.9-8.0 [P<.01]), and East Africa (AOR, 3.5; 95% CI, 1.5-6.8 [P<.01]) was found to have the strongest association with very early-onset HCC after adjusting for sex and race/ethnicity. Birth in West Africa, Central/South/other Africa, Oceania, or East Africa also was found to be strongly associated with early-onset HCC. Birth country was found to be independently associated with age at the time of HCC diagnosis in the United States. Birth in Africa (except for North Africa) and Oceania was strongly associated with very early-onset HCC. These findings have implications for the design of comprehensive HCC surveillance programs in the United States. Cancer 2016. © 2016 American Cancer Society. Cancer 2017;81-89. © 2016 American Cancer Society.

Genome-wide identification of blood DNA methylation patterns associated with early-onset hepatocellular carcinoma development in hepatitis B carriers.

The etiology of early-onset hepatocellular carcinoma (HCC) among hepatitis B virus (HBV) carriers remains unclear. DNA methylation levels in peripheral leukocytes have been associated with different environmental exposures and immune or inflammatory response. We aimed to identify methylation signatures of peripheral leukocytes that could track hepatitis B progression to HCC, especially for early-onset HCC. We first performed an epigenome-wide association analysis on 48 matched case-control pairs in a nested case-control study within a 22-yr follow-up cohort of HBV carriers. Through this analysis we found that progression to early-onset HCC involved methylation variable positions across the genome, in which a substantial proportion displayed significant variation due to HBV viral load, chronic hepatitis status, and/or leukocyte subtype composition, and these associations were significantly enriched among genes in immune pathways. Methylation at probes cg00300879, cg06872964, and cg07080864, that are located within the proximal promoter of CNKSR1, IFI44L, and PENK, respectively, was validated by bisulfite pyrosequencing and findings were replicated in a case-sibling study of early-onset HCC (134 cases vs. 174 sibling controls). Furthermore, a high methylation score, constructed using the three probes, was predictive for the risk of early-onset HCC in two datasets (adjusted-odds ratios = 0.21-0.32, P ≤ 0.0206). This association was also observed for late-onset HCC (adjusted-odds ratio = 0.42-0.47, P ≤ 0.0194) in a nested case-control study (120 cases vs. 178 controls). In prospective analysis, change in the score was detected 5-9 yr before HCC onset. Blood-based methylation profiling provides new insights into the complexity of virus-host interaction underlying HBV-related HCC, holding promise for the disease risk management. © 2016 Wiley Periodicals, Inc.

Dual oncogenic and tumor suppressor roles of the promyelocytic leukemia gene in hepatocarcinogenesis associated with hepatitis B virus surface antigen.

Proteasome-mediated degradation of promyelocytic leukemia tumor suppressor (PML) is upregulated in many viral infections and cancers. We previously showed that PML knockdown promotes early-onset hepatocellular carcinoma (HCC) in hepatitis B virus surface antigen (HBsAg)-transgenic mice. Here we report the effects of PML restoration on late-onset HBsAg-induced HCC. We compared protein expression patterns, genetic mutations and the effects of pharmacologically targeting PML in wild-type, PML−/−, PML+/+HBsAgtg/o and PML−/−HBsAgtg/o mice. PML−/− mice exhibited somatic mutations in DNA repair genes and developed severe steatosis and proliferative disorders, but not HCC. PML−/−HBsAgtg/o mice exhibited early mutations in cancer driver genes and developed hyperplasia, fatty livers and indolent adipose-like HCC. In PML+/+HBsAg-transgenic mice, HBsAg expression declined over time, and HBsAg-associated PML suppression was concomitantly relieved. Nevertheless, these mice accumulated mutations in genes contributing to oxidative stress pathways and developed aggressive late-onset angiogenic trabecular HCC. PML inhibition using non-toxic doses of arsenic trioxide selectively killed long-term HBsAg-affected liver cells in PML+/+HBsAgtg/o mice with falling HBsAg and rising PML levels, but not normal liver cells or early-onset HCC cells in PML−/−HBsAgtg/0 mice. These findings suggest dual roles for PML as a tumor-suppressor lost in early-onset HBsAg-induced hepatocarcinogenesis and as an oncogenic promoter in late-onset HBsAg-related HCC progression.

Adult-onset liver disease and hepatocellular carcinoma in S-adenosylhomocysteine hydrolase deficiency.

The etiology of liver disease remains elusive in some adults presenting with severe hepatic dysfunction. Here we describe a woman of Pakistani descent who had elevated aminotransferases at age 23. She developed muscle weakness in her mid-20s, and was diagnosed with hepatocellular carcinoma at age 29. She died without a diagnosis at age 32 after having a liver transplant. Exome sequencing revealed that she was homozygous for a missense mutation (R49H) in AHCY, the gene encoding S-adenosylhomocysteine (SAH) hydrolase. SAH hydrolase catalyzes the final step in conversion of methionine to homocysteine and inactivating mutations in this enzyme cause a rare autosomal recessive disorder, SAH hydrolase deficiency, that typically presents in infancy. An asymptomatic 7-year old son of the proband is also homozygous for the AHCY-R49H mutation and has elevated serum aminotransferase levels, as well as markedly elevated serum levels of SAH, S-adenosylmethionine (SAM), and methionine, which are hallmarks of SAH hydrolase deficiency. This report reveals several new aspects of SAH hydrolase deficiency. Affected women with SAH hydrolase deficiency can give birth to healthy children. SAH hydrolase deficiency can remain asymptomatic in childhood, and the disorder can be associated with early onset hepatocellular carcinoma. The measurement of serum amino acids should be considered in patients with liver disease or hepatocellular carcinoma of unknown etiology.

Molecular basis of aflatoxin-induced mutagenesis—role of the aflatoxin B1-formamidopyrimidine adduct

Aflatoxin B1 (AFB1) is a known carcinogen associated with early-onset hepatocellular carcinoma (HCC) and is thought to contribute to over half a million new HCCs per year. Although some of the fundamental risk factors are established, the molecular basis of AFB1-induced mutagenesis in primate cells has not been rigorously investigated. To gain insights into genome instability that is produced as a result of replicating DNAs containing AFB1 adducts, site-specific mutagenesis assays were used to establish the mutagenic potential of the persistent ring-opened AFB1 adduct, AFB1-formamidopyrimidine (AFB1-FAPY). This lesion was highly mutagenic, yielding replication error frequencies of 97%, with the predominant base substitution being a G to T transversion. This transversion is consistent with previous mutational data derived from aflatoxin-associated HCCs. In vitro translesion synthesis assays demonstrated that polymerase (pol) ζ was the most likely candidate polymerase that is responsible for the G to T mutations induced by this adduct.

Risk Factors for Early-Onset and Late-Onset Hepatocellular Carcinoma in Asian Immigrants With Hepatitis B in the United States

Routine screening for hepatocellular carcinoma (HCC) is recommended in chronic hepatitis B (HBV) patients with cirrhosis and select non-cirrhotic HBV populations including Asian males ages 40 and older and females ages 50 and older. However, many younger HBV patients develop HCC and there have been few studies examining this group. Additionally, studies of HCC in the Asian immigrant population in the United States have been limited. The objective of this study was to determine the associated risk factors for the development of early-onset (males and females under ages 40 and 50, respectively) and late-onset HCC in immigrants with chronic HBV in the United States. Clinical, demographic, and laboratory data were retrospectively collected on all Asian immigrants with HBV at Bellevue Hospital Center from 2003 to 2009. Patients with HCC were identified within this cohort. Features of early-onset and late-onset HCC cases were compared with age-matched HBV controls without HCC. We identified 168 cases of HCC in Asians with HBV. In all, 74% (124/168) of cases were late-onset, and 26% (44/168) were early-onset. When comparing the 124 late-onset HCC cases with 199 age-matched HBV controls, gender (odds ratio (OR)=4.4; P<0.05) and cirrhosis (OR=9.6; P<0.05) or surrogate labs (i.e., platelets, international normalized ratio, total bilirubin, albumin) were found to be associated with HCC development. When comparing the 44 early-onset HCC cases with 432 age-matched HBV controls, family history of HCC (OR=2.7; P<0.05), and smoking history (OR=3.4; P<0.05) were independently associated risk factors in addition to gender (OR=2.7; P<0.05), and cirrhosis (OR=19.5; P<0.05) or surrogate labs. In all, 54.8% of late-onset HCC cases were cirrhotic and 29.5% of early-onset HCC cases were cirrhotic. HCC occurs in Asian immigrant HBV patients younger than currently recommended screening guidelines. A large majority of these early-onset patients did not have cirrhosis at the time of their HCC diagnosis; therefore, factors other than cirrhosis need to be considered when evaluating HCC risk in young patients. Factors associated with HCC development across all ages include cirrhosis and male gender, while family history and smoking history may identify younger Asian immigrant HBV patients at risk for HCC. Prospective validation, including cost-effectiveness evaluation, is necessary, but our results suggest that younger Asian HBV patients, especially those with a smoking history or family history of HCC, appear to have an increased risk for HCC and should be considered for enrollment in early screening programs regardless of their age.