Conversion therapy in liver transplantation for hepatocellular carcinoma: What's new in the era of molecular and immune therapy?

Downstaging of Hepatocellular Carcinoma Before Liver Transplantation: Current Advances in Selection Criteria and Therapeutic Options

Liver transplantation (LT) is an ideal therapeutic option for selected patients with hepatocellular carcinoma (HCC). The selection criteria of HCC for LT have evolved in recent decades. Downstaging therapy is a promising strategy for patients with tumor burden beyond transplant criteria to increase the chance of receiving LT and improve posttransplant survival. Downstaging therapy is also a selection tool that refines the conventional selection criteria based on tumor morphology. Recently, the success of systemic treatment, including immune checkpoint inhibitors, antiangiogenic tyrosine kinase inhibitors, and VEGF inhibitors, in advanced HCC has prompted the discussion regarding the role of systemic therapies for HCC downstaging before transplantation. In this review, we aimed to summarize the current advances in selection criteria and therapeutic options of downstaging therapy for HCC before LT.

The Absence of Intra-Tumoral Tertiary Lymphoid Structures is Associated with a Worse Prognosis and mTOR Signaling Activation in Hepatocellular Carcinoma with Liver Transplantation: A Multicenter Retrospective Study

Tertiary lymphoid structure (TLS) can predict the prognosis and sensitivity of tumors to immune checkpoint inhibitors (ICIs) therapy, whether it can be noninvasively predicted by radiomics in hepatocellular carcinoma with liver transplantation (HCC-LT) has not been explored. In this study, it is found that intra-tumoral TLS abundance is significantly correlated with recurrence-free survival (RFS) and overall survival (OS). Tumor tissues with TLS are characterized by inflammatory signatures and high infiltration of antitumor immune cells, while those without TLS exhibit uncontrolled cell cycle progression and activated mTOR signaling by bulk and single-cell RNA-seq analyses. The regulators involved in mTOR signaling (RHEB and LAMTOR4) and S-phase (RFC2, PSMC2, and ORC5) are highly expressed in HCC with low TLS. In addition, the largest cohort of HCC patients is studied with available radiomics data, and a classifier is built to detect the presence of TLS in a non-invasive manner. The classifier demonstrates remarkable performance in predicting intra-tumoral TLS abundance in both training and test sets, achieving areas under receiver operating characteristic curve (AUCs) of 92.9% and 90.2% respectively. In summary, the absence of intra-tumoral TLS abundance is associated with mTOR signaling activation and uncontrolled cell cycle progression in tumor cells, indicating unfavorable prognosis in HCC-LT.

Re-exploration of immunotherapy targeting EMT of hepatocellular carcinoma: Starting from the NF-κB pathway

Hepatocellular carcinoma (HCC) is the fifth most common malignancies worldwide, and its high morbidity and mortality have brought a heavy burden to the global public health system. Due to the concealment of its onset, the limitation of treatment, the acquisition of multi-drug resistance and radiation resistance, the treatment of HCC cannot achieve satisfactory results. Epithelial mesenchymal transformation (EMT) is a key process that induces progression, distant metastasis, and therapeutic resistance to a variety of malignant tumors, including HCC. Therefore, targeting EMT has become a promising tumor immunotherapy method for HCC. The NF-κB pathway is a key regulatory pathway for EMT. Targeting this pathway has shown potential to inhibit HCC infiltration, invasion, distant metastasis, and therapeutic resistance. At present, there are still some controversies about this pathway and new ideas of combined therapy, which need to be further explored. This article reviews the progress of immunotherapy in improving EMT development in HCC cells by exploring the mechanism of regulating EMT.

TuBG1 promotes hepatocellular carcinoma via ATR/P53-apoptosis and cycling pathways

BACKGROUND

As reported, γ-tubulin (TuBG1) is related to the occurrence and development of various types of malignant tumors. However, its role in hepatocellular cancer (HCC) is not clear. The present study was to investigate the relationship between TuBG1 and clinical parameters and survival in HCC patients.

METHODS

The correlation between TuBG1 and clinical parameters and survival in HCC patients was explored by bioinformatics analysis. Immunohistochemistry was used for the verification. The molecular function of TuBG1 was measured using colony formation, scratch assay, trans-well assay and flow cytometry. Gene set enrichment analysis (GSEA) was used to pick up the enriched pathways, followed by investigating the target pathways using Western blotting. The tumor-immune system interactions and drug bank database (TISIDB) was used to evaluate TuBG1 and immunity. Based on the TuBG1-related immune genes, a prognostic model was constructed and was further validated internally and externally.

RESULTS

The bioinformatic analysis found high expressed TuBG1 in HCC tissue, which was confirmed using immunohistochemistry and Western blotting. After silencing the TuBG1 in HCC cell lines, more G1 arrested cells were found, cell proliferation and invasion were inhibited, and apoptosis was promoted. Furthermore, the silence of TuBG1 increased the expressions of Ataxia-Telangiectasia and Rad-3 (ATR), phospho-P38 mitogen-activated protein kinase (P-P38MAPK), phospho-P53 (P-P53), B-cell lymphoma-2 associated X protein (Bax), cleaved caspase 3 and P21; decreased the expressions of B-cell lymphoma-2 (Bcl-2), cyclin D1, cyclin E2, cyclin-dependent kinase 2 (CDK2) and CDK4. The correlation analysis of immunohistochemistry and clinical parameters and survival data revealed that TuBG1 was negatively correlated with the overall survival. The constructed immune prognosis model could effectively evaluate the prognosis.

CONCLUSIONS

The increased expression of TuBG1 in HCC is associated with poor prognosis, which might be involved in the occurrence and development of HCC.

Systemic therapies in hepatocellular carcinoma: A revolution?

The evolution in systemic therapies in hepatocellular carcinoma (HCC) signifies a strategy of high-cost, high-gain innovation that originated with sorafenib, despite its limited impact on tumor response. This strategic approach paved the way for the emergence of a second wave of the short-lived competitive advantage, exemplified by the incorporation of atezolizumab plus bevacizumab and tremelimumab plus durvalumab. In the context of safety concerns within the liver cancer domain, the IMBRAVE150 and HIMALAYA trials boldly incorporated bevacizumab and tremelimumab, respectively, demonstrating the continuation of the high-risk, high-reward innovation paradigm. This review delves into the strengths, weaknesses, opportunities, and threats analysis of systemic therapies in the field of HCC.

Insights into the history and tendency of liver transplantation for liver cancer: a bibliometric-based visual analysis

Research on liver transplantation (LT) for liver cancer has gained increasing attention. This paper has comprehensively described the current status, hotspots and trends in this field. A total of 2991 relevant articles from 1 January 1963 to 28 February 2023 were obtained from the Web of Science Core Collection. VOSviewer and CiteSpace software were utilized as bibliometric tools to analyze and visualize knowledge mapping. Between 1963 and 2023, the number of papers in the area of LT for liver cancer increased continuously. A total of 70 countries/regions, 2303 institutions and 14 840 researchers have published research articles, with the United States and China being the two most productive countries. Our bibliometric-based visual analysis revealed the expansion of LT indications for liver cancer and the prevention/treatment of cancer recurrence as ongoing research hotspots over the past decades. Meanwhile, emerging studies also focus on downstaging/bridging treatments before LT and the long-term survival of LT recipient, in particular the precise application of immunosuppressants.

Systematic sequential therapy for ex vivo liver resection and autotransplantation: A case report and review of literature

BACKGROUND

Perihilar cholangiocarcinoma (pCCA) is a highly malignant tumor arising from the biliary tree. Radical surgery is the only treatment offering a chance of long-term survival. However, limited by the tumor's anatomic location and peri-vascular invasion, most patients lose the chance for curative treatment. Therefore, more methods to increase the resectability of tumors as well as to improve outcomes are needed.

CASE SUMMARY

A 68-year-old female patient had a hepatic hilar mass without obvious symptoms. Laboratory results showed hepatitis B positivity. Magnetic resonance imaging indicated that the mass (maximum diameter: 41 mm) invaded the left and right branches of the main portal vein, as well as the middle, left and right hepatic veins; enlarged lymph nodes were also detected in the hilum. The patient was diagnosed with pCCA, and the clinical stage was determined to be T4N1M0 (stage IIIC). Considering the tumor's anatomic location and vascular invasion, systematic conversion therapy followed by ex vivo liver resection and autotransplantation (ELRA) was determined as personalized treatment for this patient. Our original systemic sequential therapeutic strategy (lenvatinib and tislelizumab in combination with gemcitabine and cisplatin) was successfully adopted as conversion therapy because she achieved partial response after three cycles of treatment, without severe toxicity. ELRA, anastomotic reconstruction of the middle hepatic vein, right hepatic vein, root of portal vein, inferior vena cava and right hepatic artery, and lymph node dissection were performed at one month after systemic therapy. Pathological and immunohistochemical examination confirmed the diagnosis of pCCA with lymph node metastasis. Although the middle hepatic vein was partially obstructed four months later, hepatic vein stent implantation successfully addressed this problem. The patient has survived for 22 mo after the diagnosis, with no evidence of recurrence or metastasis.

CONCLUSION

An effective therapeutic strategy for conversion therapy greatly increases the feasibility and efficiency of ELRA.

Perspective on the Role of Gut Microbiome in the Treatment of Hepatocellular Carcinoma with Immune Checkpoint Inhibitors

Background and Objectives: Hepatocellular carcinoma (HCC) is the leading cause of liver cancer worldwide and has a high mortality rate. Its incidence has increased due to metabolic-associated liver disease (MAFLD) epidemics. Liver transplantation and surgery remain the most resolute measures. Despite the optimistic use of multi-kinase inhibitors, namely sorafenib, the co-existence of chronic liver disease made the response rate low in these patients. Immune checkpoint inhibitors (ICIs) have become a promising hope for certain advanced solid tumors and, also, for advanced HCC. Unfortunately, a large cohort of patients with HCC fail to respond to immunotherapy. Materials and Methods: We conducted a narrative search on the main medical databases for original articles, reviews, meta-analyses, randomized clinical trials, and case series using the following keywords and acronyms and their associations: hepatocellular carcinoma, immunotherapy, checkpoint inhibitors, gut microbiota, and fecal microbiota transplantation. Results: ICIs are a promising and sufficiently safe treatment option for HCC. In detail, they have significantly improved survival and prognosis in these patients vs. sorafenib. Although there are several highlighted mechanisms of resistance, the gut microbiota signature can be used both as a response biomarker and as an effect enhancer. Practically, probiotic dose-finding and fecal microbiota transplantation are the weapons that can be used to increase ICI's treatment-response-reducing resistance mechanisms. Conclusion: Immunotherapy has been a significant step-up in HCC treatment, and gut microbiota modulation is an effective liaison to increase its efficacy.

Evolving Landscape in Liver Transplantation for Hepatocellular Carcinoma: From Stage Migration to Immunotherapy Revolution

Liver transplantation (LT) represents the primary curative option for HCC. Despite the extension of transplantation criteria and conversion with down-staging loco-regional treatments, transplantation is not always possible. The introduction of new standards of care in advanced HCC including a combination of immune checkpoint inhibitor-based therapies led to an improvement in response rates and could represent a promising strategy for down-staging the tumor burden. In this review, we identify reports and series, comprising a total of 43 patients who received immune checkpoint inhibitors as bridging or down-staging therapies prior to LT. Overall, treated patients registered an objective response rate of 21%, and 14 patients were reduced within the Milan criteria. Graft rejection was reported in seven patients, resulting in the death of four patients; in the remaining cases, LT was performed safely after immunotherapy. Further investigations are required to define the duration of immune checkpoint inhibitors, their minimum washout period and the LT long-term safety of this strategy. Some randomized clinical trials including immunotherapy combinations, loco-regional treatment and/or tyrosine kinase inhibitors are ongoing and will likely determine the appropriateness of immune checkpoint inhibitors' administration before LT.