Nivolumab for recurrent/metastatic hypopharyngeal squamous cell carcinoma in a liver transplant recipient

Liver Transplantation for Hepatocellular Carcinoma in the Era of Immune Checkpoint Inhibitors

Hepatocellular carcinoma (HCC) remains the leading oncological indication for liver transplantation (LT), with evolving and broadened inclusion criteria. Immune checkpoint inhibitors (ICIs) gained a central role in systemic HCC treatment and showed potential in the peri-transplant setting as downstaging/bridging therapy before LT or as a treatment for HCC recurrence following LT. However, the antagonistic mechanisms of action between ICIs and immunosuppressive drugs pose significant challenges, particularly regarding the risk of acute rejection (AR). This review analyzes the main signaling pathways targeted by ICI therapies and summarizes current studies on ICI therapy before and after LT. The literature on this topic is limited and highly heterogeneous, precluding definitive evidence-based conclusions. The use of ICIs before LT appears promising, provided that a sufficient wash-out period is implemented. In contrast, the results of post-LT ICI therapy do not support its wide clinical application due to high AR rates and overall poor response to treatment. In the future, modern graft preservation techniques might support the selection of good ICI responders, but data from high-level studies are urgently needed.

Transplant Oncology: An Emerging Discipline of Cancer Treatment

Transplant oncology is an emerging concept of cancer treatment with a promising prospective outcome. The applications of oncology, transplant medicine, and surgery are the core of transplant oncology to improve patients' survival and quality of life. The main concept of transplant oncology is to radically cure cancer by removing the diseased organ and replacing it with a healthy one, aiming to improve the survival outcomes and quality of life of cancer patients. Subsequently, it seeks to expand the treatment options and research for hepatobiliary malignancies, which have seen significantly improved survival outcomes after the implementation of liver transplantation (LT). In the case of colorectal cancer (CRC) in the transplant setting, where the liver is the most common site of metastasis of patients who are considered to have unresectable disease, initial studies have shown improved survival for LT treatment compared to palliative therapy interventions. The indications of LT for hepatobiliary malignancies have been slowly expanded over the years beyond Milan criteria in a stepwise manner. However, the outcome improvements and overall patient survival are limited to the specifics of the setting and systematic intervention options. This review aims to illustrate the representative concepts and history of transplant oncology as an emerging discipline for the management of hepatobiliary malignancies, in addition to other emerging concepts, such as the uses of immunotherapy in a peri-transplant setting as well as the use of circulating tumor DNA (ctDNA) for surveillance post-transplantation.

Immunotherapy and Liver Transplantation: A Narrative Review of Basic and Clinical Data

Immune checkpoint inhibitors (ICIs) have improved the management of patients with intermediate- and advanced-stage HCC, even making some of them potential candidates for liver transplantation. However, acute rejection has been observed after ICI therapy, challenging its safety in transplant settings. We summarize the key basic impact of immune checkpoints on HCC and liver transplantation. We analyze the available case reports and case series on the use of ICI therapy prior to and after liver transplantation. A three-month washout period is desirable between ICI therapy and liver transplantation to reduce the risk of acute rejection. Whenever possible, ICIs should be avoided after liver transplantation, and especially so early after a transplant. Globally, more robust prospective data in the field are required.

Immunotherapy for hepatocellular carcinoma recurrence after liver transplantation, can we harness the power of immune checkpoint inhibitors?

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death globally and liver transplantation (LT) can serve as the best curative treatment option. However, HCC recurrence after LT remains the major obstacle to the long-term survival of recipients. Recently, immune checkpoint inhibitors (ICIs) have revolutionized the treatment of many cancers and provided a new treatment strategy for post-LT HCC recurrence. Evidence has been accumulated with the real-world application of ICIs in patients with post-LT HCC recurrence. Notably, the use of these agents as immunity boosters in recipients treated with immunosuppressors is still controversial. In this review, we summarized the immunotherapy for post-LT HCC recurrence and conducted an efficacy and safety evaluation based on the current experience of ICIs for post-LT HCC recurrence. In addition, we further discussed the potential mechanism of ICIs and immunosuppressive agents in regulating the balance between immune immunosuppression and lasting anti-tumor immunity.

Immune checkpoint inhibitors in malignancies after liver transplantation: A systematic review and pooled analysis

BACKGROUND AND AIMS

Treatment of de novo malignancies and recurrent hepatocellular carcinoma with immune checkpoint inhibitors (ICI) in liver transplant recipients (LT) is an attractive strategy that is infrequently pursued because of the lack of strong evidence regarding their safety and efficacy. In this systematic review with pooled analysis, we aimed to assess safety and efficacy of ICI therapy following LT.

METHODS

We performed a systematic search of case reports and series published until January 2022. We included 31 publications reporting a total of 52 patients treated with ICIs after LT and assessed in a pooled analysis the risk of graft rejection and the outcome of ICI therapy.

RESULTS

Acute graft rejection occurred in 15 patients (28.8%) and 7 patients (13.4% of the total cohort) died because of graft loss. Rejection was associated with shorter overall survival (OS) (17.2 months, confidence interval [CI] 12.1-22.2 vs. 3.5 months, CI 1.6-5.4, p < 0.001). Disease control rate was 44.2% (n = 23), and in these patients, OS was longer than in non-responders (26.4 months, CI 20.8-32.0 vs. 3.4 months, CI 2.1-4.7, p < 0.001).

CONCLUSIONS

Observational, off-label experience suggests that treatment with ICI for advanced malignancies in LT recipients might not be discarded a priori. This notwithstanding, ICI treatment in these patients is associated with a substantial risk of graft rejection and mortality. Prospective studies are needed to provide adequate safety and efficacy figures of ICI treatment in this fragile population.

Immune checkpoint inhibitor therapy for malignant tumors in liver transplantation recipients: A systematic review of the literature

BACKGROUND

Treatment for de novo or recurrent tumors of liver transplantation (LT) recipients is challenging and immune checkpoint inhibitor (ICI) is recently well developed and could be a potentially effective option for this population. There remains limited evidence on the safety and efficacy of ICI therapy in LT recipients.

METHODS

A systematic literature search was conducted on PubMed database through April 1, 2022, to identify publications reporting ICI treatment for malignant tumors in LT recipients. We summarized the allograft rejection, mortality, and tumor response of ICI treatment.

RESULTS

24 articles with 41 LT recipients were identified. The age of LT recipients ranged from 14 to 78, 76.2% were male, 56.1% had recurrent HCC, and 87.8% received anti-PD-1 therapy. Allograft rejection occurred in 31.7% of patients, death was reported in 46.3% and 6 cases died secondary to allograft rejection. Progressive disease rate of this population was 48.8% and 10 patients responded to immunotherapy. Half of recipients with positive PD-L1 staining (4/8) experienced allograft rejection.

CONCLUSIONS

ICI therapy has potential therapeutic value on malignant tumors for LT recipients, accompanied by a high rate of allograft rejection and mortality. PD-L1 expression, type of ICI, and immunosuppression agent should be taken into consideration before initiation of immunotherapy. Further studies are needed to optimize this anticancer treatment approach in these patients.

An analysis report on the application of immune checkpoint inhibitors after liver transplantation

Up to now, a variety of immune checkpoint inhibitors (ICIs) have been proved to have good therapeutic effects in the treatment of hepatocellular carcinoma (HCC). However, the effects of their applications in liver transplant (LT) recipients are still unclear. In this analysis report, the clinical applications and therapeutic effects of ICIs on LT recipients with hepatic tumor recurrence or de novo carcinoma based on eight databases, including PubMed, EMBASE, Web of Science, Google Scholar, China National Knowledge Infrastructure, Wanfang Data, and CQVIP, were investigated. And the prior treatment, disease response, adverse reactions, and prognosis of patients with malignant tumors after LT and receiving ICI treatments were analyzed. After screening, a total of 28 articles with 47 recipients on the application of ICIs after LT were included. In these patients, their median age was 57 (14–71) years and the main type of tumor after LT was HCC (59.6%). The overall remission rate following ICI treatment was 29.8% (14/47) and the disease progression rate was 68.1% (32/47). Among all these patients, 31.9% (15/47) of patients had immune rejection; the median survival time was 6.5 (0.3–48) months, and the fatality rate was 61.7% (29/47). Considering that the therapeutic effect of ICIs in LT recipients with HCC recurrence or de novo carcinoma is not ideal, ICI treatment should be carefully considered for LT patients, and further research is needed.