Terapia génica: ¿Qué es y para qué sirve?

Gene therapy has developed as a method of approach to the treatment of human diseases based on the transfer of genetic material to the cells of an individual. Normally, the aim of this transfer of genetic material is to re-establish a cellular function that has been abolished or is defective, to introduce a new function or to interfere with an existing function. Thus, the different gene therapy strategies are based on the combination of three key elements: the genetic material to be transferred, the method of transfer and the cellular type that will incorporate this genetic material. Attention was initially centred on the treatment of monogenic hereditary diseases, but subsequently the majority of clinical trials (over four hundred) have concerned the treatment of cancer. In China a genetic product has been approved for commercialisation: an adenovirus that transfers the correct version of the tumour suppressor gene p53. And, in the late 1990s, a group of children with severe combined immunodeficiency were successfully treated through the ex vivo transfer of the correct version of the altered gene to their bone marrow, although some of these children later developed lymphoproliferative syndromes due to the activation of an oncogen in the corrected cells. Human gene therapy is feasible and can be useful, but the tools need improving for it to become part of the therapeutic arsenal

Targets for immunotherapy of liver cancer

Drug development in hepatocellular carcinoma (HCC) has been characterised by many failures in the past. Despite good rationales and promising phase II data, many phase III trials failed. Immunotherapy represents an alternative treatment approach that has been successful in many different cancer types. As an inflammation induced cancer, HCC represents a very interesting target for immune based approaches. Indeed, early results from clinical trials testing immune checkpoint inhibitors are not only promising, but have already led to evaluation in a phase III setting. Herein, we summarise our current knowledge on the rationale, mechanism of action and clinical data for immune checkpoint blockade in HCC. In addition, we provide an overview of other novel immune based approaches currently under development for the treatment of HCC, such as adoptive cell based and antibody-based approaches

Tratamiento de la infección crónica por el VHB

The treatment of the patient with chronic hepatitis B virus infection (HBV) must be carried out with the knowledge that the percentage of patients infected with the B virus that develop chronic hepatitis remains between 5-10%. Of these, 10-30% will present chronic infection with active viral replication, necroinflammatory hepatic lesion, evolution to hepatic cirrhosis and the risk of developing hepatocarcinoma. For this reason, the aim of treatment is to achieve negativisation of the HBeAg, seroconversion to anti-HBe and a reduction of viral replication to undetectable values (estimated by level of DNA-HBV), for protracted periods of time. When a sustained loss of HBeAg and a reduction of viral replication are obtained, a biochemical, clinical and histological remission is achieved. Up until now the therapeutic alternatives in chronic infection by the B virus have been immunomodulation with Interferon alpha and the blocking of viral replication with lamivudine or adefovir dipivoxil. A difference must be drawn between the biochemical response, defined as a fall in the transaminases to normal values, and the virological response, which refers to a fall in the levels of DNA-HBV below 10(5) copies/ml. Finally, the complete response is defined as the virological and biochemical response with negativisation of the HBsAg. If a sustained response is obtained for several months, a histological response can be predicted with reduction in the intensity of the hepatic lesion and an absence or stabilisation in the process of fibrosis. The sustained response should last for no less than 6 to 12 months following the end of treatmen

Gene therapy of liver cancer

The application of gene transfer technologies to the treatment of cancer has led to the development of new experimental approaches like gene directed enzyme/pro-drug therapy (GDEPT), inhibition of oncogenes and restoration of tumor-suppressor genes. In addition, gene therapy has a big impact on other fields like cancer immunotherapy, anti-angiogenic therapy and virotherapy. These strategies are being evaluated for the treatment of primary and metastatic liver cancer and some of them have reached clinical phases. We present a review on the basis and the actual status of gene therapy approaches applied to liver cancer

New therapies for hepatocellular carcinoma

Hepatocellular carcinoma (HCC), one of the most common cancers worldwide, is often diagnosed at an advanced stage when most potentially curative therapies such as resection, transplantation or percutaneous and transarterial interventions are of limited efficacy. The fact that HCC is resistant to conventional chemotherapy, and is rarely amenable to radiotherapy, leaves this disease with no effective therapeutic options and a very poor prognosis. Therefore, the development of more effective therapeutic tools and strategies is much needed. HCCs are phenotypically and genetically heterogeneous tumors that commonly emerge on a background of chronic liver disease. However, in spite of this heterogeneity recent insights into the biology of HCC suggest that certain signaling pathways and molecular alterations are likely to play essential roles in HCC development by promoting cell growth and survival. The identification of such mechanisms may open new avenues for the prevention and treatment of HCC through the development of targeted therapies. In this review we will describe the new potential therapeutic targets and clinical developments that have emerged from progress in the knowledge of HCC biology, In addition, recent advances in gene therapy and combined cell and gene therapy, together with new radiotherapy techniques and immunotherapy in patients with HCC will be discussed

Radioembolization versus chemoembolization for unresectable hepatocellular carcinoma: a meta-analysis of randomized trials

PURPOSE: This study aimed to compare clinically relevant outcomes following transarterial chemoembolization (TACE) and transarterial radioembolization (TARE) in patients with unresectable hepatocellular carcinoma (HCC) using only prospective randomized clinical trials as a source of information. MATERIALS AND METHODS: A meta-analysis was performed to compare the efficacy of TARE and TACE in treating patients with unresectable HCC. Only prospective randomized trials were included in the quantitative analysis. Overall and progression-free survival, disease control rate, and transplantation rate were the variables under analysis. RESULTS: Overall survival at 1 year was similar between the two treatment groups (OR =1.31, 95% CI: 0.56-3.04, P=0.53). Progression-free survival at 1 year was also not statistically different between the two treatments (OR =0.23, 95% CI: 0.02-2.45, P=0.22). Although a higher proportion of patients underwent transplantation in the TARE group (30% vs 20.8%), this difference was not statistically significant (OR =0.68, 95% CI: 0.23-2.01; P=0.49). CONCLUSION: TARE and TACE provide similar outcomes in unresectable HCC. The role of TARE should be explored in selected patient subpopulations in future clinical trials

Selective internal radiation therapy: an effective treatment for hormonal syndromes in pancreatic neuroendocrine tumors

The hormone secretion in pancreatic neuroendocrine tumors (pNET) causes an important interference in patients' quality of life. We present two cases of pNET metastatic to the liver (a pancreatic endocrine carcinoma with a severe hormonal syndrome and an insulinoma with severe crisis of hypoglycemia and coma) refractory to conventional treatments, which were finally solved with selective internal radiation therapy (SIRT), a nonstandard level 1 therapy. We show two examples of an excellent control of symptoms together with a long survival after treatment with SIRT. The evidence supporting the use of this therapy is level 2. Our case reports strongly support the use of SIRT for the severe clinical syndrome in pNET metastatic to the liver and refractory to somatostatin analogs

Nonsurgical treatment for localized hepatocellular carcinoma

The most common non-surgical approaches for the treatment of localized hepatocellular carcinoma remain hepatic artery-delivered particles laden with chemotherapy (TACE), or radioactive microparticles (TARE). External beam radiotherapy has been an effective option in many parts of the world for selected HCC patients, but now has an expanded role with stereotactic and proton beam technologies. This review focuses on existing evidence and current guidance for utilizing these modalities for localized, but unresectable, non-transplantable HCC patients