Jean Frédéric Blanc

Exome sequencing of hepatocellular carcinomas identifies new mutational signatures and potential therapeutic targets

Genomic analyses promise to improve tumor characterization to optimize personalized treatment for patients with hepatocellular carcinoma (HCC). Exome sequencing analysis of 243 liver tumors identified mutational signatures associated with specific risk factors, mainly combined alcohol and tobacco consumption and exposure to aflatoxin B1. We identified 161 putative driver genes associated with 11 recurrently altered pathways. Associations of mutations defined 3 groups of genes related to risk factors and centered on CTNNB1 (alcohol), TP53 (hepatitis B virus, HBV) and AXIN1. Analyses according to tumor stage progression identified TERT promoter mutation as an early event, whereas FGF3, FGF4, FGF19 or CCND1 amplification and TP53 and CDKN2A alterations appeared at more advanced stages in aggressive tumors. In 28% of the tumors, we identified genetic alterations potentially targetable by US Food and Drug Administration (FDA)–approved drugs. In conclusion, we identified risk factor–specific mutational signatures and defined the extensive landscape of altered genes and pathways in HCC, which will be useful to design clinical trials for targeted therapy.

Benign and Malignant Vascular Tumors of the Liver in Adults

Vascular tumors of the liver in adult patients include cavernous hemangioma, a common benign tumor; epithelioid hemangioendothelioma, a rare, usually low-grade malignant tumor; and angiosarcoma, a rare and very aggressive tumor. All these primary mesenchymal tumors develop on a normal liver and may also affect other organs. Their pathogenesis remains largely unknown. Hepatic tumors are increasingly detected incidentally due to widespread use of modern abdominal imaging techniques. Therefore, reliable noninvasive characterization and differentiation of such liver tumors is of major importance for clinical practice. Hemangioma follows a benign course, and a nonoperative approach for the majority of these lesions is recommended. A definitive diagnosis of epithelioid hemangioendothelioma and angiosarcoma requires histopathologic examination. Liver transplantation at an early stage has greatly improved the prognosis of epithelioid hemangioendothelioma. The prognosis of angiosarcoma remains dismal. Designing a worldwide database that contains all data about patients with these rare diseases is recommended.

The identification of small nodules in liver adenomatosis.

BACKGROUND/AIMS Liver adenomatosis is characterized by the presence of multiple adenomas of various sizes in the liver. The aim of this study was to characterize the morphology of small nodules which can be difficult to identify. METHODS Seven patients included in this study underwent surgery for the removal of one or several nodules. All, but one, were females. Three out of seven presented with acute bleeding. Five had six or more nodules at presentation, and two only one, who developed nodules later on during follow-up. RESULTS All of the large nodules that were >2 cm, except one, were typical adenomas with or without hemorrhagic areas. Smaller nodules (1-2 cm), some of which discovered on the resected specimen were either typical adenomas or non-typical nodules. These non-typical nodules were characterized by a polylobulated aspect with steatotic zones, and in between, bands of non-steatotic hepatocytes with portal tracts-like structures containing occasional cytokeratin 7 and less often cytokeratin 19 positive biliary cells. Numerous steatotic foci were also seen in four cases. They were isolated or grouped forming microadenomas or non-typical micronodules (<1 cm) containing biliary elements. Our findings lead to the following hypothesis: adenomatosis is characterized by the simultaneous occurrence of multiple adenomas; if several adenomatous foci expand at the same time in the same area, they will form one polylobulated nodule containing non-adenomatous tissue with portal tracts in between areas of adenomatous tissue (non-typical micronodule). Such a small micronodule may in turn expand and join another micronodule to form a bigger one by the same process (non-typical nodule). As nodules grow, their non-adenomatous components including hepatocytic plates and portal tracts constituents will progressively disappear to end up with the classical aspect of an adenoma. CONCLUSIONS This hypothesis supports the concept that non-typical nodules/micronodules are adenomas precursors. However, they can be difficult to classify since they resemble focal nodular hyperplasia precursor.

Prognosis of advanced hepatocellular carcinoma: a new stratification of Barcelona Clinic Liver Cancer stage C: results from a French multicenter study.

Background Advanced hepatocellular carcinoma (HCC) includes a wide spectrum of tumors and patients’ prognosis after treatment is highly variable. Moreover, therapeutic options based on the Barcelona Clinic Liver Cancer (BCLC) staging system algorithm are restricted to one systemic therapy. Aim of the study To refine the stratification among BCLC C HCC patients by establishing a new simple prognostic score. Patients and methods A regression model based on a BCLC stage C population and validated with an external cohort of BCLC C HCC patients defined the score. It was therefore validated among three external cohorts of BCLC C HCC patients treated with sorafenib. Results Five variables had independent prognostic values: the number of nodules, the infiltrating nature of the HCC, &agr;-fetoprotein serum level, Child–Pugh score, and Eastern Cooperative Oncology Group Performance Status grade. They were integrated into a new score named NIACE ranging from 0 to 7, well correlated with survival. With the use of one threshold value, this score enables defining of two populations with different survivals among BCLC C patients and specifically among those treated with sorafenib. Conclusion The NIACE score defines different prognostic subgroups after palliative treatment of HCC. It could be an additional tool for BCLC C HCC before inclusion in clinical trials or for the management of patients. These results must be validated in a prospective study.

Pathological Diagnosis of Hepatocellular Cellular Adenoma according to the Clinical Context

In Europe and North America, hepatocellular adenomas (HCA) occur, classically, in middle-aged woman taking oral contraceptives. Twenty percent of women, however, are not exposed to oral contraceptives; HCA can more rarely occur in men, children, and women over 65 years. HCA have been observed in many pathological conditions such as glycogenosis, familial adenomatous polyposis, MODY3, after male hormone administration, and in vascular diseases. Obesity is frequent particularly in inflammatory HCA. The background liver is often normal, but steatosis is a frequent finding particularly in inflammatory HCA. The diagnosis of HCA is more difficult when the background liver is fibrotic, notably in vascular diseases. HCA can be solitary, or multiple or in great number (adenomatosis). When nodules are multiple, they are usually of the same subtype. HNF1α-inactivated HCA occur almost exclusively in woman. The most important point of the classification is the identification of β-catenin mutated HCA, a strong argument to identify patients at risk of malignant transformation. Some HCA already present criteria indicating malignant transformation. When the whole nodule is a hepatocellular carcinoma, it is extremely difficult to prove that it is the consequence of a former HCA. It is occasionally difficult to identify HCA remodeled by necrosis or hemorrhage.

Multiple black hepatocellular adenomas in a male patient.

A 65-year-old man presented with multiple liver tumours. Imaging techniques could not differentiate between adenomas and hepatocellular carcinomas. He had no relevant past medical history. Liver function tests were normal except for a 1.5-fold rise in GGT. AFP was normal. Viral markers were negative. During laparoscopy, numerous black tumours of different sizes were seen. These tumours were adenomas without malignant transformation. Tumoral hepatocytes contained a brown pigment in the canalicular area without evidence of cholestasis. This pigment was Fontana positive and looked like Dubin-Johnson pigment by electron microscopy. The expression of the canalicular multispecific organic anion transporter (cMOAT) was decreased in the tumours but normal in the non-tumoral liver ruling out the diagnosis of Dubin-Johnson syndrome. There was mild iron deposition possibly related to an homozygous H63D mutation in the HFE gene. Three years after their discovery, the size of the tumours remained stable. It is concluded that this male patient with multiple adenomas and mild iron overload is at risk of developing an hepatocellular carcinoma and that the black colour of adenomas is probably due to a partial defect in excretion of organic anions.

Expression of leukemia inhibitory factor (LIF) and its receptor gp190 in human liver and in cultured human liver myofibroblasts. Cloning of new isoforms of LIF mRNA

BackgroundThe cytokine leukemia inhibitory factor (LIF) mediates its biological effects through binding to its high affinity receptor made of the low-affinity LIF receptor subunit gp190 (LIF-R) and the gp130 subunit. LIF exerts several important effects in the liver, however, data on liver expression of LIF are scarce. The aim of this study was to examine the expression of LIF and LIF-R in human liver.ResultsLIF expression, analyzed by immunohistochemistry, was barely detectable in normal liver but was strong within cirrhotic fibrous septa and was found in spindle-shaped cells compatible with myofibroblasts. Accordingly, cultured human liver myofibroblasts expressed high levels of LIF as shown by ELISA and Northern blot. Biological assay demonstrated that myofibroblast-derived LIF was fully active. RT-PCR showed expression of the LIF-D and M isoforms, and also of low levels of new variants of LIF-D and LIF-M resulting from deletion of exon 2 through alternative splicing. LIF receptor expression was detected mainly as a continuous sinusoidal staining that was enhanced in cirrhotic liver, suggestive of endothelial cell and/or hepatocyte labeling. Immunohistochemistry, flow cytometry and STAT-3 phosphorylation assays did not provide evidence for LIF receptor expression by myofibroblasts themselves. LIF secretion by cultured myofibroblasts was down regulated by the addition of interleukin-4.ConclusionsWe show for the first time the expression of LIF in human liver myofibroblasts, as well as of two new isoforms of LIF mRNA. Expression of LIF by myofibroblasts and of its receptor by adjacent cells suggests a potential LIF paracrine loop in human liver that may play a role in the regulation of intra-hepatic inflammation.

76 A MOLECULAR SIGNATURE AND ALGORITHM FOR THE DIAGNOSIS AND PROGNOSIS OF HEPATOCELLULAR TUMORS

Background: HBsAg plays a role in suppressing the immune system and may allow maintenance of chronic liver infection. REP 9AC inhibits the release of HBsAg from infected hepatocytes. In preclinical studies surface antigen seroclearance occurred after two weeks of treatment and four weeks of treatment resulted in 55% of animals achieving a durable SVR. REP 9AC is currently being evaluated in patients with chronic HBV in a proof of concept clinical trial. An updated report on interim clinical trial data will be presented. Methods: Patients were HBsAg+ with pre-treatment HBVDNA titers between 10 and 10 copies/ml and had significant liver fibrosis. Safety and virologic response (HBVDNA, HBsAg, anti-HBs) were assessed at the trial site and by confirmatory testing (HBsAg, HBeAg, anti-HBs, anti-HBe) of frozen serum samples using the ArchitectTM testing platform. Results: At the time of abstract submission, 5 of 8 patients treated have cleared serum HBsAg as early as 7 days and no later than 15 weeks following initiation of treatment at higher doses. AntiHBsAg antibodies have been observed in 7 out of 8 patients. Six, patients have achieved a 3 to 7 log reduction in their HBVDNA titers from pre-treatment levels after 7–13 weeks of treatment and three of these patients have achieved complete control of their infection after 20–27 weeks of treatment (HBVDNA−, HBsAg−, HBeAg−, antiHBs +, anti-HBe +) and are being followed off treatment. These 3 patients are currently maintaining control over their infections 14, 27 and 52 weeks after stopping treatment. Conclusions: REP 9AC can rapidly clear serum HBsAg in infected patients which appears to allow the restoration of an effective immune response, leading to the achievement of SVRs in three patients to date. These results suggest that REP 9AC may become an important new tool in the treatment of chronic hepatitis B.

PNPLA3 and TM6SF2 variants as risk factors of hepatocellular carcinoma across various etiologies and severity of underlying liver diseases: TM6SF2, PNPLA3 and hepatocellular carcinoma

Few single nucleotide polymorphisms (SNPs) have been reproducibly associated with hepatocellular carcinoma (HCC). Our aim was to test the association between nine SNPs and HCC occurrence. SNPs in genes linked to HCC (DEPDC5, GRIK1, KIF1B, STAT4, MICA, DLC1, DDX18) or to liver damage (PNPLA3‐rs738409, TM6SF2‐rs58542926) in GWAS were genotyped in discovery cohorts including 1,020 HCC, 2,021 controls with chronic liver disease and 2,484 healthy individuals and replication was performed in prospective cohorts of cirrhotic patients with alcoholic liver disease (ALD, n = 249) and hepatitis C (n = 268). In the discovery cohort, PNPLA3 and TM6SF2 SNPs were associated with HCC (OR = 1.67 [CI95%:1.16–2.40], p = 0.005; OR = 1.45 [CI95%:1.08–1.94], p = 0.01) after adjustment for fibrosis, age, gender and etiology. In contrast, STAT4‐rs7574865 was associated with HCC only in HBV infected patients (p = 0.03) and the other tested SNP were not linked with HCC risk. PNPLA3 and TM6SF2 variants were independently associated with HCC in patients with ALD (OR = 3.91 [CI95%:2.52–6.06], p = 1.14E‐09; OR = 1.79 [CI95%:1.25–2.56], p = 0.001) but not with other etiologies. PNPLA3 SNP was also significantly associated with HCC developed on a nonfibrotic liver (OR = 2.19 [CI95%:1.22–3.92], p = 0.007). The association of PNPLA3 and TM6SF2 with HCC risk was confirmed in the prospective cohort with ALD. A genetic score including PNPLA3 and TM6SF2 minor alleles showed a progressive significant increased risk of HCC in ALD patients. In conclusion, PNPLA3‐rs738409 and TM6SF2‐rs58542926 are inherited risk variants of HCC development in patients with ALD in a dose dependent manner. The link between PNPLA3 and HCC on nonfibrotic liver suggests a direct role in liver carcinogenesis.

CYP1A2 is a predictor of HCC recurrence in HCV-related chronic liver disease: A retrospective multicentric validation study

BACKGROUND Although hepatic resection is a potentially curative treatment for hepatocellular carcinoma (HCC), post-operative prognosis remains unsatisfactory due to the high incidence of recurrence. Several clinicopathological markers have been associated with HCC recurrence, but none has been validated. Extratumoral expression of cytochrome P4501A2 (CYP1A2) was recently proposed as predictor of HCC recurrence. AIMS To validate extratumoral CYP1A2 as predictor of HCC recurrence and to determine its applicability to pretreatment liver biopsy. METHODS Surgically resected HCC (n.180) with clinicopathological data and follow up were retrospectively studied (HCV n.54; HBV n.91; NAFLD/NASH n.35). CYP1A2 expression was evaluated using an immunohistochemical assay and semiquantitative analysis. RESULTS Etiology-stratified analysis showed that low CYP1A2 expression was independently associated with recurrence-free survival in HCV patients (HR 2.814, 95% CI 1.300-6.093, p=0.009); this association was lost in the whole cohort. Pretreatment liver biopsy and paired surgical specimens showed concordant CYP1A2 expression in the vast majority of cases (87%), with NPV of 100%, PPV of 81.25%, and a Cohen kappa of 0.72 (substantial agreement). CONCLUSION We validated the extratumoral expression of CYP1A2 as a biomarker of HCC recurrence in HCV patients. CYP1A2 analysis in pretreatment liver biopsy can be of help to stratify HCC patients for personalized treatment.