HCC recurrence in HCV-infected patients after liver transplantation: SiLVER Study reveals benefits of sirolimus in combination with CNIs - a post-hoc analysis

Sirolimus Attenuates Calcineurin Inhibitor-Induced Epithelial-Mesenchymal Transition in Hepatocellular Carcinoma

BACKGROUND

Calcineurin inhibitors (CNIs), which are potent immunosuppressants (ISs), increase the risk for hepatocellular carcinoma (HCC) recurrence after liver transplantation (LTx). Epithelial-mesenchymal transition (EMT) is a key process in which epithelial cancer cells lose their polarity, resulting in cancer progression and metastasis. The aim of this study was to evaluate the effect of sirolimus (SRL) individually and in combination with other ISs to reduce EMT.

METHODS

HCC SK-Hep1 cells were used and various ISs (SRL, tacrolimus, cyclosporine A, or mycophenolate mofetil) were administered at 2 dosages and in combination therapies. Mice were transplanted with SK-Hep1 cells (in the liver) and were monitored after 2 weeks.

RESULTS

The in vitro treatment with SRL showed a dose-dependent attenuation of cell proliferation and migration in case of the individual and IS combination treatments; further, decreased levels of pro-EMT proteins, namely, N-cadherin, transforming growth factor-β, ZEB1, Slug, and Snail were observed. In contrast, E-cadherin expression was upregulated after both the individual and IS combination treatments. These results were also observed in the samples from mice transplanted with the SK-Hep1 cells.

CONCLUSION

The present study demonstrated that SRL reduced HCC metastasis by inhibiting EMT. Thus, our findings provide a rationale for the use of SRL in combination with ISs in HCC LTx patients.

The Importance of the Immunosuppressive Regime on Hepatocellular Carcinoma Recurrence After Liver Transplantation

PURPOSE

Hepatocellular carcinoma (HCC) recurrence after liver transplantation (LT) occurs in approximately 20% of recipients and these patients have median about one year survival after diagnosis. Some immunosuppressive drugs can cause development of HCC recurrence, on the other hand some immunosuppressive drugs may have a positive effect for preventing HCC recurrence. Thus, immunosuppression (IS) modification may play a role in preventing HCC recurrence.

METHODS

In this review, we analyzed IS treatment strategy in two parts: before HCC recurrence following LT and after HCC recurrence following LT, and after HCC recurrence following LT.

RESULTS

There is no proven, optimal IS protocol to prevent HCC recurrence after transplantation. Therefore, individualized immunosuppressive treatments should be tailored to the biological behaviour of HCC. Forcing the immune tolerance in terms of recurrence can probably be expressed as the most appropriate post LT period. Once HCC recurrence has developed after transplantation, again, there is no commonly accepted, optimal IS treatment, but there is a tendency to switch to IS modifications that include mTORi by minimizing CNIs and MMF.

CONCLUSION

There is a need for well-designed, randomized, controlled clinical studies with larger numbers of patients on this subject.

Influence of everolimus-based treatment on circulating regulatory T cells after liver transplantation: Comparative study with tacrolimus-based therapy

Liver transplantation remains the only treatment for terminal liver diseases. However, immunosuppressive drugs required for allograft acceptance are toxic and may be responsible for severe side effects. Modulating the immune system to induce tolerance is a promising approach to reduce immunosuppressive regimen. More particularly, promoting natural CD4⁺ CD25⁺ FoxP3⁺ Tregs could be crucial in achieving tolerance. Contrary to calcineurin inhibitors, reports indicate that mTOR inhibitors may have a positive impact on Tregs. Here we present the first randomized prospective clinical study where Tregs levels from liver transplanted patients receiving either tacrolimus or everolimus were monitored for 6 months, starting from the day of transplantation. A total of 30 patients from four centers were monitored. Blood samples were obtained at day 0, day 14, one month, three months and six months post-transplantation. Flow-cytometry immunophenotyping of Tregs (CD4⁺ CD25⁺ CD127^- FoxP3⁺) and functional assays with Tregs were performed to assess their immunosuppressive capacity. Levels of Tregs were significantly reduced after one month of standard tacrolimus-based immunosuppressive regimen (p<0.05). Four months after conversion, levels of Tregs from patients treated with everolimus was significantly higher than patients under tacrolimus (p<0.02). Functional assays demonstrated that Tregs conserved their capacity to suppress the proliferation of activated PBMC.

Incorporating Tumor Biology to Predict Hepatocellular Carcinoma Recurrence in Patients Undergoing Living Donor Liver Transplantation Using Expanded Selection Criteria

Conventional selection criteria for liver transplantation (LT) in patients with hepatocellular carcinoma (HCC) are based on tumour size/number only, and do not consider vital surrogates of tumor biology such as alpha-fetoprotein (AFP) and tumor [¹⁸ F]fluorodeoxyglucose positron emission tomography ([¹⁸ F]FDG PET) avidity. We analyzed survival outcomes, and predictors of HCC recurrence in 405 patients with cirrhosis and HCC (HCC-cirr) who underwent living donor LT (LDLT) using our expanded selection criteria: no extrahepatic disease or major vascular invasion, irrespective of tumor size/number. Fifty-one percent patients had tumours beyond Milan, and 43% beyond the University of California San Francisco [UCSF] criteria. The 5-year overall survival (OS) and recurrence-free survival (RFS) were 64% and 70%, respectively. Three preoperatively available factors predicted recurrence: pre-LT AFP ≥100 ng/mL (P = 0.005; hazard ratio [HR], 2.190), tumor burden beyond the UCSF criteria (P = 0.001; HR, 2.640), and [¹⁸ F]FDG PET avidity (P = 0.004; HR, 2.442). A prognostic model based on the number and combination of the aforementioned preoperative risk factors was developed using a competing-risk RFS model. Three risk groups were identified: low (none or a single risk factor present, 9.3% recurrence), moderate (AFP ≥100 ng/mL and [¹⁸ F]FDG PET avidity, or beyond UCSF tumor and [¹⁸ F]FDG PET avidity, 25% recurrence), and high (AFP ≥100 ng/mL and beyond UCSF, or presence of all 3 risk factors, 46% recurrence). Acceptable long-term outcomes were achieved using our expanded selection criteria. Our prognostic model to predict recurrence based on preoperative biological and morphological factors could guide pretransplant management (downstaging versus upfront LDLT) with the aim of reducing post-LDLT recurrence.