Management options for primary hepatocellular carcinoma. An overview

Surgical resection versus liver transplant for patients with hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma is a major worldwide health problem, involving more than half a million new patients yearly, with a different incidence in different parts of the world. Hepatocellular carcinoma develops in about 80% of cirrhotic patients, and cirrhosis is considered the strongest predisposing factor for it. Surgical resection and liver transplantation are conventional treatment modalities that can offer long-term survival for patients with hepatocellular carcinoma.

OBJECTIVES

To assess the benefits and harms of surgical resection compared with those of liver transplantation in patients with hepatocellular carcinoma.

SEARCH METHODS

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded (SCI-EXPANDED) at ISI Web of Science (last search February 2013). We also searched the abstracts from annual meetings of the American Society of Clinical Oncology, the American Association for the Study of Liver Diseases (AASLD), and the European Association for the Study of the Liver (EASL), provided through The Cochrane Hepato-Biliary Group until February 2013.

SELECTION CRITERIA

Randomised clinical trials comparing surgical resection and hepatic transplantation.

DATA COLLECTION AND ANALYSIS

The search strategies were run and two authors individually evaluated whether the retrieved studies fulfilled the inclusion criteria.

MAIN RESULTS

No randomised clinical trials comparing surgical resection and liver transplantation as the major methods of treating hepatocellular carcinoma were found.

AUTHORS' CONCLUSIONS

There are no randomised clinical trials comparing surgical resection and liver transplantation for hepatocellular carcinoma treatment.

Down-regulation of tyrosine aminotransferase at a frequently deleted region 16q22 contributes to the pathogenesis of hepatocellular carcinoma

Loss of 16q is one of the most frequent alterations in many malignancies including hepatocellular carcinomas (HCC), suggesting the existence of a tumor suppressor gene (TSG) within the frequently deleted region. In this report we describe the identification and characterization of one candidate TSG, tyrosine aminotransferase gene (TAT), at 16q22.1. Loss of one TAT allele was detected in 27/50 (54%) of primary HCCs by quantitative real-time polymerase chain reaction. In addition, homo-deletion of TAT alleles was detected in two cases. Down-regulation of TAT was detected in 28/50 (56%) of HCCs, which was significantly associated with the loss of TAT allele and hypermethylation of TAT 5' CpG island (CGI) region (P < 0.001). Functional studies found that TAT has a strong tumor suppressive ability. Introduction of the TAT gene into HCC cell lines could effectively inhibit colony formation in soft agar, foci formation, and tumor formation in nude mice. Further study found that the tumor suppressive mechanism of TAT was associated with its proapoptotic role in a mitochondrial-dependent manner by promoting cytochrome-c release and activating caspase-9 and PARP.

CONCLUSION

Taken together, our findings suggest that TAT plays an important suppressive role in the development and progression of HCC.

Is transarterial chemoembolization necessary before liver transplantation for hepatocellular carcinoma?

BACKGROUND

Transarterial chemoembolization (TACE) before liver transplantation (LT) for hepatocellular carcinoma (HCC) has been proposed to prevent tumor progression, thus decreasing tumor recurrence and increasing survival.

METHODS

We studied 46 patients undergoing LT for HCC who were divided in 2 groups--group A with pretransplant TACE (18 patients [39.1%]) and group B without pretransplant TACE (28 patients [60.9%])--and compared postoperative and long-term results between the 2 groups.

RESULTS

There were no statistical differences in morbidity, transfusion needles, and postoperative time between-and no acute arterial or portal complication in-the 2 groups. There were no statistical differences in tumor recurrence (16.7 % vs 36.4 %, P=.16) with regard to pathway (mainly extrahepatic) or time. In group A patients, mean survival was 89.3+/-21.7 months with 1-, 3-, and 5-year actuarial survival rates of 83.3%, 60.5%, and 60.5%, respectively. In group B patients, mean survival was 75.1+/-19.1 months with 1-, 3-, and 5-year actuarial survival rates of 77.2%, 58.7%, and 38.1%, respectively. The differences in mean survival were not statistically significant (PX .56), nor was 5-year disease-free survival, which was 54% in group A and 39.5% in group B (P=.8).

CONCLUSIONS

TACE is a safe procedure for candidates on the wait list who are scheduled for LT to treat HCC. Although TACE does not correlate with increased intraoperative difficulties or postoperative complications, it does not significantly improve tumor recurrence and survival.

Prognostic features and survival of hepatocellular carcinoma in Italy: impact of stage of disease

The aim of this study was to evaluate the prognostic factors at presentation and survival in Italian patients with hepatocellular carcinoma (HCC). Clinical and demographic data of 176 patients consecutively observed from 1993 to 1997 were evaluated by univariate and multivariate analyses. Overall median survival was 18 months. At univariate analysis, low albumin, high bilirubin, high alkaline phosphatase, high alpha-fetoprotein (AFP); high platelet count, hepatitis B surface antigen (HBsAg)-positivity, the presence of ascites, of encephalopathy, of portal vein thrombosis (PVT), male sex, no treatment, poor differentiation, untreatable tumours and incidental diagnosis were each associated with shorter survival. HBsAg-positive subjects more often presented with untreatable lesions or diffuse tumours (P=0.001 and P=0.007, respectively) and had significantly worse survival (P=0.0057). By multiple regression analysis, low albumin, high bilirubin, abnormal AFP, presence of PVT and of untreatable lesions were independent risk factors for worse survival. Thus, the most important factors influencing survival are the degree of functional impairment of the liver, the presence of hepatitis B viral (HBV) infection, the type of diagnosis and the aggressiveness of the tumour.

Genotoxic potential of porphyrin type photosensitizers with particular emphasis on 5-aminolevulinic acid: implications for clinical photodynamic therapy

Photodynamic therapy (PDT) uses exogenously administered photosensitizers activated by light to induce cell death or modulation of immunological cascades, presumably via formation of reactive oxygen species (ROS). 5-Aminolevulinic acid (ALA) mediated photosensitization is increasingly used for the treatment of nonmelanoma skin cancer and other indications including benign skin disorders. Long-term side effects of this investigational modality are presently unknown. Just as tumor treatments such as ionizing radiation and chemotherapy can cause secondary tumor induction, PDT may potentially have a carcinogenic risk. Evaluation of the biological effects of ALA in absence of activating light and analysis of the mechanism of ALA-PDT and porphyrin-type photosensitizers mediated photosensitization indicate that this therapy has a pro-oxidant and genotoxic potential. However, porphyrin type molecules also possess antioxidant and antimutagenic properties. ALA-PDT delays photocarcinogenesis in mice, and topical ALA alone does not increase skin cancer incidence in these animals. Patients with increased tissue levels of ALA have an increased incidence of internal carcinoma, however, it is not clear whether this relationship is casual or causal. There is no evidence indicating higher rates of skin cancer in patients with photosensitivity diseases due to presence of high protoporphyrin IX (PP) levels in skin. Overall, the presently available data indicate that the risk for secondary skin carcinoma after topical ALA-PDT seems to be low, but further studies must be carried out to evaluate the carcinogenic risk of ALA-PDT in conditions predisposed to skin cancer.

Hepatocellular carcinoma

Primary hepatocellular carcinoma is one of the 10 most common tumours, and the most common primary liver malignancy, in the world. In the majority of cases, it occurs against a background of hepatitis B or C viral infection and/or liver cirrhosis, and is associated with a dismal prognosis of a few months. Current treatments in routine clinical practice are surgical resection and liver transplantation, but these therapies are applicable to only a small proportion of patients and prolongation of survival is restricted. Other treatment options include intra-arterial chemotherapy, transcatheter arterial chemoembolisation, percutaneous ethanol injection, cryotherapy, thermotherapy, proton therapy, or a wide range of their possible combinations. The current lack of definitive data, however, limits the use of these therapies. Another option is gene therapy, which although in its infancy at the present time, may have a significant role to play in the future management of hepatocellular carcinoma.

[Diagnosis and therapy of hepatocellular carcinoma]

During the past decade, the diagnostic technologies concerning the hepatocellular carcinoma have been enriched by the vascular doppler ultrasound, the ultrasound echo-enhancing agents and the magnetic resonance tomography. The therapeutic possibilities have been augmented by the percutaneous ethanol instillation therapy, the combination of local therapies with transcatheter arterial embolisation and the more effective after-treatment after transplantation and segment resection. The use of the respective treatment modalities depends on the tumor constellation, the functional liver reserve, the patients general condition and the risk/benefit ratio of the treatment. The quality of life should be optimized because of the poor tumor prognosis. As there have been no real advances in the treatment of hepatocellular carcinoma to date, the prevention and early diagnosis of the tumor in high risk populations is of utmost importance.

Non-surgical treatment of hepatocellular carcinoma

A decade ago, surgery was the only satisfactory treatment modality for hepatocellular carcinoma (HCC), but it was limited only to selected cases. For the majority of cases of HCC, systemic chemotherapy was one of the few treatment alternatives, but provided only marginal benefit. In the past 20 years, diagnostic methods have improved to an extent that small HCC less than 1 cm can be detected. Moreover, non-surgical treatment is available, of which regional therapy has been shown to prolong patients' survival, and may even replace surgical resection in some cases. Regional therapy is indicated for the treatment of HCC when there is no extrahepatic metastasis and the patient has adequate liver function reserve, thus permitting repeated therapy. Transcatheter hepatic arterial embolization (TAE) using various embolizers has been well documented to include controlled studies. However, it is not indicated for patients with thrombosed main portal veins. Its therapeutic effect is also doubtful when the tumour is infiltrative in nature or is hypovascular, too large or too small. Additional chemotherapeutic agents mixed into the embolizer with lipiodol and degraded starch microspheres or styrene-maleic acid-neocarzinostatin in which chemotherapeutic agents are embedded, are used with a better response, but the survival rate has not shown significant improvement. Ultrasound-guided local injection therapy is another new method of treatment of HCC. Of these techniques, percutaneous ethanol injection therapy (PEIT) is widely used with excellent results for small, encapsulated tumours in livers with less than three HCC. Percutaneous ethanol injection therapy can also be used in cases with portal vein thrombosis, but it is not suitable for patients having coagulopathy or ascites. Using acetic acid, OK-432, interferon or anti-cancer drugs in the injection therapy shows no further benefit over ethanol alone. Transcatheter echoguided thermotherapy or cryotherapy has been reported in small series of patients, as has target therapy with immune or radiotherapy and conformal radiotherapy. Preliminary studies show encouraging results. Systemic therapy with either single drug or multidrugs is ineffective, with a response rate of less than 20%. Immunotherapy, such as with interferon or other cytokines, is not beneficial. Hormone therapy has not been promising, except for treatment with tamoxifen, which has been reported to show some beneficial effect. Gene therapy is still in its infancy. In summary, recent progress in non-surgical treatment of HCC has resulted in a breakthrough of regional therapy looking quite promising. Moreover, a combination of different types of regional therapies may yield better outcomes in selected individuals.

In vivo antitumor effects of electrochemotherapy in a hepatoma model

The use of in vivo electroporation in combination with a chemotherapeutic agent (electrochemotherapy) for the treatment of liver tumors was examined. Induced rat hepatomas were treated with a 0.5 unit intratumor bleomycin dose followed by rectangular direct current pulses. Six pulses were administered during treatment using a needle array electrode that rotated the applied electric field around the tumors. A 84.6% objective response rate resulted for tumors that received both bleomycin and electric pulses. Control groups that received partial or no treatment showed less than 10% objective response rates. These results indicate that electrochemotherapy can be translated from the treatment of cutaneous cancers to the treatment of liver tumors and other internal tumors.

Hepatocellular carcinoma cells resist necrosis during anoxia by preventing phospholipase-mediated calpain activation

Although hepatocellular carcinoma (HCC) cells are more resistant to anoxic injury than normal hepatocytes, the mechanisms responsible for this differential sensitivity remain obscure. Because enhanced calpain protease activity contributes to hepatocyte necrosis, we tested the hypothesis that HCC cells resist anoxia by preventing calpain activation. Cell viability in two rat HCC cell lines (N1S1 and McA-RH7777 cells) was fourfold greater compared to rat hepatocytes after 4 h of anoxia. Although calpain activity increased twofold in rat hepatocytes during anoxia, no increase in calpain activity occurred in HCC cells. Western and Northern blot analysis revealed greater or equivalent expression of calpains and calpastatin in HCC cells compared to hepatocytes. Because increases in cytosolic free Ca++ (Cai++) and phospholipid degradation products regulate calpains in vitro, we measured Cai++ and phospholipid degradation. Ca++i did not change in any cell types during 60 min of anoxia. In contrast, phospholipid degradation was fourfold greater in hepatocytes compared to HCC cells. Melittin, a phospholipase A2 activator, increased calpain activity and cell necrosis in all cell types; melittin-induced cell necrosis was ameliorated by a calpain protease inhibitor. In summary, these data demonstrate for the first time 1) calpain activation without a measureable increase in Ca++i, 2) phospholipase-mediated calpain activation in hepatocytes and HCC cells, and 3) the adaptive mechanism responsible for the resistance of HCC cells to anoxia-an inhibition of phospholipid-mediated calpain activation. Interruption of phospholipase-mediated calpain activation may be a therapeutic strategy for preventing anoxic cell injury.