Role of contrast enhanced ultrasonography in the assessment of hepatic metastases: A review

Contrast enhanced ultrasonography (CEUS) has improved both the detection and characterization of focal liver lesions. It is now possible to evaluate in real time the perfusion of focal liver lesions in the arterial, portal and late contrast phases, and thus to characterize focal liver lesions with high diagnostic accuracy. As a result, CEUS has taken a central diagnostic role in the evaluation of focal liver lesions that are indeterminate upon computed tomography (CT) and magnetic resonance imaging. The combined use of second generation contrast agents and low mechanical index techniques is essential for the detection of liver metastases, and it now allows the examination of the entire liver in both the portal and late phases. Several studies have shown that using CEUS instead of conventional ultrasonography without contrast agents significantly improves sensitivity in detection of liver metastases. Furthermore, the detection rate with CEUS seems to be similar to that of CT. This review describes the clinical role of CEUS in detecting liver metastases, including details about examination techniques, features of metastases observed with CEUS, and clinical results and guidelines.

Synchronous development of HCC and CCC in the same subsegment of the liver in a patient with type C liver cirrhosis

As a result of having undergone computed tomography (CT), a 75-year-old woman with type-C liver cirrhosiswas shown to have two tumors on the ventral and dorsal sides of subsegment 3 (S3). The tumor on the ventral side was diagnosed as a classic hepatocellular carcinoma (HCC), while that on the dorsal side was considered atypical for a HCC. Although the indocyanine green (ICG) findings indicated poor hepatic reserve, the prothrombin time (PT) was relatively good. An operation was performed in February 2007; however, this resulted in exploratory laparotomy. Dynamic CT performed 12 mo after the operation revealed that the tumor on the dorsal side of S3 had apparently increased. The marginal portion of the tumor was shown to be in the early and parenchymal phases, while the internal portion was found to have grown only slightly in the delayed phase. We diagnosed this tumor as a cholangiocellular carcinoma (CCC). S3 subsegmentectomy was performed in April 2008. The tumor on the ventral side was pathologically diagnosed as a moderately differentiated HCC, and that on the dorsal side was diagnosed as a CCC. We can therefore report a rare case of synchronous development of HCC and CCC in the same subsegment of the liver in a patient with type-C liver cirrhosis. We also add a literature review for all the reported cases published in Japan and around the world, and summarize the features of double cancer exhibiting both HCC and CCC.

Proteinases and their inhibitors in liver cancer

Proteinases are known to be involved in many cancer-related processes, particularly in the breakdown of extracellular matrix barriers in the course of tumor invasion and metastasis. In this review we summarize the current knowledge about the role of the most important matrix-degrading proteinases (cathepsins, matrix metalloproteinases, plasmin/plasminogen activators) and their respective inhibitors in liver cancer progression and metastasis.

Metabolic restaging of hepatocellular carcinoma using whole-body F-FDG PET/CT

AIM

To evaluate the ability of (18)F-fluorodeoxyglucose positron emission and computed tomography ((18)F-FDG PET/CT) in restaging of hepatocellular carcinoma (HCC) after treatment.

METHODS

We reviewed a database of the diagnostic performance of (18)F-FDG PET/CT scan for patients with HCC following local or regional treatment. The database consisted of (18)F-FDG PET/CT information of 21 male and 4 female (age range, 27-81 years; mean age, 51.6 years) patients who had received surgical resection and/or interventional treatments and then underwent (18)F-FDG PET/CT scan. All patients had received enhanced CT scan of the liver two weeks before or after the (18)F-FDG PET/CT scan. Intrahepatic recurrence and/or extrahepatic metastases were confirmed by histological analysis or clinical and imaging follow-up. The accuracy of (18)F-FDG PET/CT study was determined by histopathological results or by clinical and imaging follow-up.

RESULTS

(18)F-FDG PET/CT was abnormal in 19 of the 25 (76.0%) patients. In detecting HCC recurrence, (18)F-FDG PET/CT scored 17 true positives, 5 true negatives, 2 false positives and 1 false negative. The sensitivity, specificity and accuracy of (18)F-FDG PET/CT in detecting HCC recurrence was 89.5%, 83.3% and 88%, respectively. (18)F-FDG PET/CT had an impact on management of these patients by settling the problem of an unexplained increase in alpha-fetoprotein after treatment (14 patients), by monitoring response to the treatment and guiding additional regional therapy (12 patients), by identifying extrahepatic metastases (10 patients), by identifying tumor growth or thrombosis in the portal vein (6 patients), or by guiding surgical resection of extrahepatic metastases (2 patients).

CONCLUSION

Our results suggest that whole body (18)F-FDG PET/CT may be useful in the early evaluation of residual, intrahepatic recurrent or extrahepatic metastatic lesions and able to provide valuable information for the management of HCC recurrence.

Surveillance and diagnosis of hepatocellular carcinoma in patients with cirrhosis

Early identification of hepatocellular carcinoma (HCC) is more frequent because of surveillance programs for HCC worldwide. The optimal strategy of surveillance in cirrhosis is a current topical issue. In terms of diagnosis, recent advances in non-invasive imaging technology, including various techniques of harmonic ultrasound, new ultrasound contrast agents, multi-slice helical computed tomography and rapid high quality magnetic resonance, have all improved the accuracy of diagnosis. Consequently the role of liver biopsy in diagnosis of HCC has declined. The imaging diagnosis relies on the hallmark of arterial hypervascularity with portal venous washout. However, with recent advances in genomics and proteomics a great number of potential serum and tissue markers have been identified and are being developed as new candidate markers for both diagnosis and prognosis of hepatocellular carcinoma, and may increase the need for liver biopsy.

Oxidative stress signaling underlying liver disease and hepatoprotective mechanisms

Oxidative stress is a redox imbalance between pro-oxidants and antioxidants in favour of the former ones, leading to different responses depending on the level of pro-oxidants and the duration of the exposure. In this article, we discuss the damaging or cytoprotective signaling mechanisms associated with oxidative stress by addressing (1) the role of prolonged and severe oxidative stress and insulin resistance as determinant factors in the pathogenesis of non-alcoholic fatty liver disease associated with obesity, which, with the concurrence of nutritional factors, may determine the onset of fatty liver and its progression to steatohepatitis; and (2) the development of an acute and mild pro-oxidant state by thyroid hormone administration, which elicits the redox up-regulation of the expression of proteins affording cell protection, as a preconditioning strategy against ischemia-reperfusion liver injury.

Recent insights on risk factors of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a disease prevalent in many populations worldwide. It initiates many economic and health problems in management modalities and leads to increasing mortality rates. Worldwide, trials have attempted to discover specific early markers for detection and prediction of the disease, hoping to set a more precise strategy for liver cancer prevention. Unfortunately, many economic, cultural and disciplinary levels contribute to confounding preventive strategies. Many risk factors contribute to predisposition to HCC, which can present individually or simultaneously. Previous articles discussed many risk factors for hepatocellular carcinogenesis; however, most of them didn't consider collectively the most recent data relating to causes. In this article, the pathogenesis and risk factors of HCC are discussed. Most of the intermediary steps of HCC involve molecular and transcriptional events leading to hepatocyte malignant transformation. These steps are mainly triggered by hepatitis B, C or transfusion-transmitted virus, either alone, or with other factors. Diabetes seems to be a major contributing risk factor. Schistosomiasis, a blood infestation, mostly affects Nile basin inhabitants leading to bladder, renal and hepatic cancers. Alcoholism, food and water pollutants and some drugs can also lead to HCC. Additionally, some hereditary diseases, as hemochromatosis, α-1-antitrypsin deficiency and tyrosinaemia are known to lead to the development of HCC, if not well managed.

Future perspectives on the treatment of hepatocellular carcinoma with cisplatin

Hepatocellular carcinoma (HCC) is the commonest primary liver malignancy. Its incidence is increasing worldwide. Surgery, including transplantation resection, is currently the most effective treatment for HCC. However, recurrence rates are high and long-term survival is poor. Conventional cytotoxic chemotherapy has not provided clinical benefit or prolonged survival for patients with advanced HCC. Cisplatin (CDDP) is a key drug for the standard regimens of various cancers in the respiratory, digestive and genitourinary organs. Recently, several encouraging results have been shown in using CDDP in the treatment of advanced HCC patients. This review examines current knowledge regarding the chemotherapeutic potential of CDDP.

Activins and follistatins: Emerging roles in liver physiology and cancer

Activins are secreted proteins belonging to the TGF-β family of signaling molecules. Activin signals are crucial for differentiation and regulation of cell proliferation and apoptosis in multiple tissues. Signal transduction by activins relies mainly on the Smad pathway, although the importance of crosstalk with additional pathways is increasingly being recognized. Activin signals are kept in balance by antagonists at multiple levels of the signaling cascade. Among these, follistatin and FLRG, two members of the emerging family of follistatin-like proteins, can bind secreted activins with high affinity, thereby blocking their access to cell surface-anchored activin receptors. In the liver, activin A is a major negative regulator of hepatocyte proliferation and can induce apoptosis. The functions of other activins expressed by hepatocytes have yet to be more clearly defined. Deregulated expression of activins and follistatin has been implicated in hepatic diseases including inflammation, fibrosis, liver failure and primary cancer. In particular, increased follistatin levels have been found in the circulation and in the tumor tissue of patients suffering from hepatocellular carcinoma as well as in animal models of liver cancer. It has been argued that up-regulation of follistatin protects neoplastic hepatocytes from activin-mediated growth inhibition and apoptosis. The use of follistatin as biomarker for liver tumor development is impeded, however, due to the presence of elevated follistatin levels already during preceding stages of liver disease. The current article summarizes our evolving understanding of the multi-faceted activities of activins and follistatins in liver physiology and cancer.

Combination treatment in HBeAg-negative chronic hepatitis B

Chronic hepatitis B (CHB) represents an important public health problem. HBeAg-negative CHB is frequently associated with advanced liver disease and its prevalence is increasing. Monotherapy with either interferon (conventional or pegylated) or nucleoside/nucleotide analogues has its limitations. It has been suggested that a combination of these agents might increase antiviral efficacy. However, existing data do not support this hypothesis, even though combination treatment appears to reduce the risk for emergence of lamivudine resistance. Nevertheless, most existing combination studies are small, and it is possible that they have not been designed to detect significant differences between combination treatment and monotherapies. Another limitation of these studies is that, in most of them, lamivudine treatment was discontinued after 1 year, a strategy that is not followed in clinical practice. It was thought to be interesting to evaluate the combination of a short course of interferon (particularly pegylated) with the long-term administration of nucleotide or nucleoside analogues. The efficacy of combining pegylated interferon with the newer nucleotide or nucleoside analogues or of nucleotide with nucleoside analogues could also be evaluated. However, findings show that until more data are available, combination therapy cannot be recommended as first-line treatment in patients with CHB. On the other hand, add-on therapy with adefovir or tenofovir is the treatment of choice in patients who develop resistance to lamivudine. In patients with cirrhosis, a combination of lamivudine/adefovir may also be used as initial treatment; another option would be to add tenofovir in patients with an insufficient response to entecavir.

Multistep carcinogenesis of perihilar cholangiocarcinoma arising in the intrahepatic large bile ducts

Flat-type "biliary intraepithelial neoplasia (BilIN)" and papillary-type "intraductal papillary neoplasm of the bile duct (IPN-B)" are proposed as precursors of invasive, perihilar intrahepatic cholangiocarcinoma (ICC). Three carcinogenetic pathways are proposed: BilIN progressing to tubular adenocarcinoma, and IPN-B progressing to tubular adenocarcinoma or to colloid carcinoma. Carcinogenesis via BilIN was characterized by mucin core protein 2-/cytokeratin 20-(MUC2-/CK20-) with MUC1 expression, while carcinogenesis via IPN-B leading to tubular adenocarcinoma was associated with MUC1 expression or that to colloid carcinoma with MUC1-negativity. In both the BilIN and IPNB series, the expression of p21, p53, and cyclin D1 was upregulated with histological progression. Interestingly, p53 expression was upregulated at the invasive stage of BilIN, but was low in noninvasive BilIN, while p53 expression was upregulated in IPN-B1 and reached a plateau in IPN-B2 and invasive ICC. Expression of p16(INK4a), which was frequent in BilIN1, was decreased in BilIN-2/3 and invasive carcinoma. EZH2 expression showed a stepwise increase from BilIN to invasive carcinoma. Membranous expression of β-catenin and E-cadherin was more markedly decreased in ICC with BilIN than in ICC with IPNB. Interestingly, disruption of the membranous distribution of β-catenin and E-cadherin seems to result in the invasion and metastasis of carcinoma cells of BilIN and IPN-B expressing MMP-7 and MT1-MMP. Increased expression of cyclin D1 and c-myc was more frequent in the IPNB lineage than BilIN lineage, possibly related to the Wnt signaling pathway associated with the nuclear accumulation of β-catenin. In conclusion, BilIN and IPN-B progress to invasive ICC through characteristic multistep processes.

Needle track seeding following percutaneous procedures for hepatocellular carcinoma

Neoplastic seeding may arise after diagnostic or therapeutic percutaneous procedures for hepatocellular carcinoma. The true incidence of seeding with hepatocellular carcinoma is difficult to assess precisely, but a significant risk of seeding exists and is greater when performing diagnostic biopsy as compared to therapeutic percutaneous procedures [radiofrequency ablation, radiofrequency ablation (RFA); percutaneous ethanol injection, Percutaneous ethanol injection (PEI)]. Whenever liver transplantation is feasible, diagnostic needle biopsies should be avoided, but RFA and PEI are often needed as "bridge" treatments. The role of adjuvant treatments in reducing the incidence of seeding following RFA or PEI requires further evaluation.

Aggressive liver resection including major-vessel resection for colorectal liver metastases

AIM

To clarify short- and long-term outcomes of combined resection of liver with major vessels in treating colorectal liver metastases.

METHODS

Clinicopathologic data were evaluated for 312 patients who underwent 371 liver resections for metastases from colorectal cancer. Twenty-five patients who underwent resection and reconstruction of retrohepatic vena cava, major hepatic veins, or hepatic venous confluence during hepatectomies were compared with other patients, who underwent conventional liver resections.

RESULTS

Morbidity was 20% (75/371) and mortality was 0.3% (1/312) in all patients after hepatectomy. Hepatic resection combined with major-vessel resection/reconstruction could be performed with acceptable morbidity (16%) and no mortality. By multivariate analysis, repeat liver resection (relative risk or RR, 5.690; P = 0.0008) was independently associated with resection/reconstruction of major vessels during hepatectomy, as were tumor size exceeding 30 mm (RR, 3.338; P = 0.0292) and prehepatectomy chemotherapy (RR, 3.485; P = 0.0083). When 312 patients who underwent a first liver resection for initial liver metastases were divided into those with conventional resection (n = 296) and those with combined resection of liver and major vessels (n = 16), overall survival and disease-free rates were significantly poorer in the combined resection group than in the conventional resection group (P = 0.02 and P < 0.01, respectively). A similar tendency concerning overall survival was observed for conventional resection (n = 37) vs major-vessel resection combined with liver resection (n = 7) performed as a second resection following liver recurrences (P = 0.09). Combined major-vessel resection at first hepatectomy (not performed; 0.512; P = 0.0394) and histologic major-vessel invasion at a second hepatectomy (negative; 0.057; P = 0.0005) were identified as independent factors affecting survival by multivariate analysis.

CONCLUSION

Hepatic resection including major-vessel resection/reconstruction for colorectal liver metastases can be performed with acceptable operative risk. However, such aggressive approaches are beneficial mainly in patients responding to effective prehepatectomy chemotherapy.

Partial blockage of hepatocyte maturation in hepatoma-derived growth factor transgenic mice

AIM

To investigate the role of hepatoma-derived growth factor (HDGF) in liver development, especially in the hepatocyte differentiation.

METHODS

We generated transgenic mice which overexpressed HDGF in hepatocytes under the transcriptional control of mouse albumin promoter/enhancer. To examine the effects of HDGF overexpression on hepatocyte differentiation, we investigated the expression patterns of the differentiation marker genes.

RESULTS

The HDGF transgenic mice developed normally and showed no apparent abnormality in the liver. However, the gene expression patterns of the liver in adult transgenic mice were similar to those of the neonatal liver in control mice.

CONCLUSION

These findings suggest that HDGF-overexpression partially suppresses hepatocyte maturation.

Hepatitis C virus and peripheral blood mononuclear cell reservoirs Patricia Baré

The existence of hepatitis C virus (HCV) infection in extrahepatic sites has been widely demonstrated. Since peripheral blood mononuclear cells have been the most investigated, compelling evidence of an association with HCV has been shown. Different studies have revealed that HCV RNA can persist and replicate in immune cells but the relevance of its presence and persistence over time is still unknown. As the contribution of this extrahepatic reservoir could have several clinical implications in viral transmission, treatment response and disease pathogenesis, future studies are required to improve our knowledge of the extrahepatic manifestations of HCV and its possible consequences.

What is the purpose of launching World Journal of Hepatology?

The first issue of World Journal of Hepatology (WJH), whose preparatory work was initiated on September 23, 2008, will be published on October 31, 2009. The WJH Editorial Board has now been established and consists of 213 distinguished experts from 29 countries. Our purpose of launching WJH is to publish peer-reviewed, high-quality articles via an open-access online publishing model, thereby acting as a platform for communication between peers and the wider public, and maximizing the benefits to editorial board members, authors and readers.