Utility of Cell-Free DNA Detection in Transplant Oncology

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.

The Diagnostic, Prognostic, and Therapeutic Potential of Cell-Free DNA with a Special Focus on COVID-19 and Other Viral Infections

Cell-free DNA (cfDNA) in human blood serum, urine, and other body fluids recently became a commonly used diagnostic marker associated with various pathologies. This is because cfDNA enables a much higher sensitivity than standard biochemical parameters. The presence of and/or increased level of cfDNA has been reported for various diseases, including viral infections, including COVID-19. Here, we review cfDNA in general, how it has been identified, where it can derive from, its molecular features, and mechanisms of release and clearance. General suitability of cfDNA for diagnostic questions, possible shortcomings and future directions are discussed, with a special focus on coronavirus infection.

Cell-Free DNA as a Surveillance Tool for Hepatocellular Carcinoma Patients after Liver Transplant

The liver is the world's sixth most common primary tumor site, responsible for approximately 5% of all cancers and over 8% of cancer-related deaths. Hepatocellular carcinoma (HCC) is the predominant type of liver cancer, accounting for approximately 75% of all primary liver tumors. A major therapeutic tool for this disease is liver transplantation. Two of the most significant issues in treating HCC are tumor recurrence and graft rejection. Currently, the detection and monitoring of HCC recurrence and graft rejection mainly consist of imaging methods, tissue biopsies, and alpha-fetoprotein (AFP) follow-up. However, they have limited accuracy and precision. One of the many possible components of cfDNA is circulating tumor DNA (ctDNA), which is cfDNA derived from tumor cells. Another important component in transplantation is donor-derived cfDNA (dd-cfDNA), derived from donor tissue. All the components of cfDNA can be analyzed in blood samples as liquid biopsies. These can play a role in determining prognosis, tumor recurrence, and graft rejection, assisting in an overall manner in clinical decision-making in the treatment of HCC.

Immune Checkpoint Inhibitors for Solid Tumors in the Adjuvant Setting: Current Progress, Future Directions, and Role in Transplant Oncology

The rationale for administering immune checkpoint inhibitors (ICIs) in the adjuvant setting is to eradicate micro-metastases and, ultimately, prolong survival. Thus far, clinical trials have demonstrated that 1-year adjuvant courses of ICIs reduce the risk of recurrence in melanoma, urothelial cancer, renal cell carcinoma, non-small cell lung cancer, and esophageal and gastroesophageal junction cancers. Overall survival benefit has been shown in melanoma while survival data are still not mature in other malignancies. Emerging data also show the feasibility of utilizing ICIs in the peri-transplant setting for hepatobiliary malignancies. While ICIs are generally well-tolerated, the development of chronic immune-related adverse events, typically endocrinopathies or neurotoxicities, as well as delayed immune-related adverse events, warrants further scrutiny regarding the optimal duration of adjuvant therapy and requires a thorough risk-benefit determination. The advent of blood-based, dynamic biomarkers such as circulating tumor DNA (ctDNA) can help detect minimal residual disease and identify the subset of patients who would likely benefit from adjuvant treatment. In addition, the characterization of tumor-infiltrating lymphocytes, neutrophil-to-lymphocyte ratio, and ctDNA-adjusted blood tumor mutation burden (bTMB) has also shown promise in predicting response to immunotherapy. Until additional, prospective studies delineate the magnitude of overall survival benefit and validate the use of predictive biomarkers, a tailored, patient-centered approach to adjuvant ICIs that includes extensive patient counseling on potentially irreversible adverse effects should be routinely incorporated into clinical practice.

"Transplantomics" for predicting allograft rejection: real-life applications and new strategies from Network Medicine

Although decades of the reductionist approach achieved great milestones in optimizing the immunosuppression therapy, traditional clinical parameters still fail in predicting both acute and chronic (mainly) rejection events leading to higher rates across all solid organ transplants. To clarify the underlying immune-related cellular and molecular mechanisms, current biomedical research is increasingly focusing on "transplantomics" which relies on a huge quantity of big data deriving from genomics, transcriptomics, epigenomics, proteomics, and metabolomics platforms. The AlloMap (gene expression) and the AlloSure (donor-derived cell-free DNA) tests represent two successful examples of how omics and liquid biopsy can really improve the precision medicine of heart and kidney transplantation. One of the major challenges in translating big data in clinically useful biomarkers is the integration and interpretation of the different layers of omics datasets. Network Medicine offers advanced bioinformatic-molecular strategies which were widely used to integrate large omics datasets and clinical information in end-stage patients to prioritize potential biomarkers and drug targets. The application of network-oriented approaches to clarify the complex nature of graft rejection is still in its infancy. Here, we briefly discuss the real-life clinical applications derived from omics datasets as well as novel opportunities for establishing predictive tests in solid organ transplantation. Also, we provide an original "graft rejection interactome" and propose network-oriented strategies which can be useful to improve precision medicine of solid organ transplantation.

Gemcitabine Plus Cisplatin Versus Non-Gemcitabine and Cisplatin Regimens as Neoadjuvant Treatment for Cholangiocarcinoma Patients Prior to Liver Transplantation: An Institution Experience

Background

Cholangiocarcinoma management is constantly being updated in view of existing evidence in order to establish practice guidelines and consensus statements. However, the available treatment guidelines to optimize outcomes for cholangiocarcinoma patients who require liver transplantation are still controversial. This study contributing to the cholangiocarcinoma care field by investigating a new promising neoadjuvant therapy that might be help to grant the liver transplant option to the patients with cholangiocarcinoma. Here, we evaluate and compare the potential efficacy of chemotherapy combination of Gemcitabine plus Cisplatin versus non- Gemcitabine and Cisplatin regimens as a neo-adjuvant treatment for cholangiocarcinoma patients prior to liver transplantation.

Methods

In this retrospective study, patients with locally advanced, unresectable, hilar, or intrahepatic cholangiocarcinoma with no evidence of extrahepatic disease or vascular involvement were treated with either the combination of neo-adjuvant Gemcitabine plus Cisplatin with no radiation or other standard options of neo-adjuvant treatment. All patients included received chemotherapy prior to being listed for liver transplantation at a single cancer center in collaboration with the same institution’s transplant center according to an open-labeled, and centers-approved clinical management protocol. Patients were listed for liver transplantation if they had a minimum of six months of scans showing response or confirmation of disease stability. The primary endpoints were the overall survival and recurrence-free survival after liver transplantation. This report, which was censored on March 18, 2022.

Results

Out of a total of 707 liver transplant recipients were screened, 37 patients were confirmed with a diagnosis of cholangiocarcinoma and only 18 patients (11 males and 7 females) with a median age of 61.83 [interquartile range: 58.27-68.74] met inclusion criteria. Of the 18 patients enrolled, 10 received Gemcitabine/Cisplatin, while 8 patients received either Gemcitabine monotherapy or Capecitabine or FOLFIRI. Months for recurrence after transplantation was 20.1 (IRQ: 20.1-20.1) in the Gemcitabine/Cisplatin group and 9.5 (8.9-12.47) months in the non-Gemcitabine/Cisplatin group (p-value=0.18). Median months of follow-up in the Gemcitabine/Cisplatin group was 28.35 (27.1-32.23) months versus 40.12 (20.6-56.22) months in the non-Gemcitabine/Cisplatin group (p-value=0.33). In non-Gemcitabine/Cisplatin patients, overall survival was 75% (95% CI 31-93%) at both years 1 and 2; 63% (95% CI 23-86%) at years 3 to 5. In Gemcitabine/Cisplatin patients, overall survival was 100% (95% CI 100-100%) at both years 1 and 2; 75% (95% CI 13-96%) at years 3 to 5. Three non-Gemcitabine/Cisplatin patients died at 328 days, 340 days, and 896 days, respectively. One Gemcitabine/Cisplatin patient died at 885 days.

Conclusion

Our findings suggest improved overall survival outcomes with Gemcitabine plus Cisplatin as neo-adjuvant treatment with no concomitant radiation compared to non-Gemcitabine/Cisplatin regimens in patients with cholangiocarcinoma prior to liver transplantation.

Immunotherapy as a Neoadjuvant Therapy for a Patient with Hepatocellular Carcinoma in the Pretransplant Setting: A Case Report

Systemic combination therapy of immune checkpoint inhibitors and vascular endothelial growth factors have provided the basis for improved outcomes in select patients with unresectable or metastatic hepatocellular carcinoma. However, for patients with resectable disease, surgery alone or an orthotopic liver transplant remains the standard of care. Within the realms of transplant oncology, neoadjuvant systemic therapy is currently being evaluated as a potential strategy to improve outcomes in patients with HCC. Here, we report excellent response with significant downstaging in a safe manner after neoadjuvant treatment with atezolizumab and bevacizumab in a patient diagnosed with poorly differentiated HCC. As a result of the significant response observed with safe outcomes, the patient was listed for orthotopic liver transplant (OLT) evaluation and transplanted successfully.

Timeline of FDA-Approved Targeted Therapy for Cholangiocarcinoma

Simple Summary

Cholangiocarcinoma constitutes around 3% of gastrointestinal cancers, and mortality from this cancer has been rising in the recent decades. Many cases of cholangiocarcinoma are unfortunately discovered in their advanced stages which cannot be treated with surgical resection alone. Targeted therapy is a type of medical treatment that has garnered significant interest due to its ability to specifically target cancer cells while sparing normal healthy cells. A few targeted therapies have just recently been approved by the United States FDA for the treatment of cholangiocarcinoma specifically. This manuscript seeks to explore the timeline of targeted therapies with either FDA approval or FDA breakthrough therapy designation. The official approval of these therapies marks a new age for the treatment of cholangiocarcinoma and brings new options for clinicians across the nation for this unfortunate disease.

Abstract

Cholangiocarcinoma (CCA) represents approximately 3% of gastrointestinal malignancies worldwide and constitutes around 10–15% of all primary liver cancers, being only second to hepatocellular carcinoma. Mortality from CCA has been on the rise in recent decades, and in the United States alone there has been a 36% increase in CCA from 1999 to 2014, with over 7000 CCA mortalities since 2013. Targeted therapies, which have been gaining interest due to their greater specificity toward cancer cells, have only recently started gaining FDA approval for the treatment of CCA. In this manuscript, we will go through the timeline of current FDA-approved targeted therapies as well as those that have gained FDA breakthrough therapy designation.

Gemcitabine and Cisplatin as Neo-Adjuvant for Cholangiocarcinoma Patients Prior to Liver Transplantation: Case-Series

Background: The management of cholangiocarcinoma is continually reviewed on a current evidence basis to develop practice guidelines and consensus statements. However, the standardized treatment guidelines are still unclear for cholangiocarcinoma patients who are listed for liver transplantation. We aimed to validate and evaluate the potential efficacy of chemotherapy combination of Gemcitabine and Cisplatin as a neo-adjuvant treatment for cholangiocarcinoma patients before liver transplantation. Methods: In this prospective case series, patients with locally advanced, unresectable, hilar, or intrahepatic cholangiocarcinoma with no evidence of extrahepatic disease or vascular involvement were treated with a combination of neoadjuvant gemcitabine and cisplatin with no radiation. All patients included received chemotherapy prior to being listed for liver transplantation at a single cancer center according to an open-labeled, and center-approved clinical management protocol. The primary endpoints were the overall survival and recurrence-free survival after liver transplantation. Results: Between 1 March 2016, and 15 March 2022, 10 patients (8 males and 2 females) with a median age of 62.71(interquartile range: 60.02–71.87) had a confirmed diagnosis of intrahepatic or hilar cholangiocarcinoma and underwent liver transplantation. Median days of neoadjuvant therapy for a given combination of gemcitabine and cisplatin were 181 (IRQ: 120–250). Nine patients (90%) were reported with no recurrence or metastasis, and only 1 patient had confirmed metastasis (10%); days for metastasis after transplantation were 612 for this patient. All patients received a combination of gemcitabine and cisplatin as neo-adjuvant while awaiting liver transplantation. The median days of follow-up were 851 (813–967). Overall survival was 100% (95% CI 100–100%) at both years one and two; 75% (95% CI 13–96%) at years three to five. One patient died at eight hundred and eighty-five days. No adverse events were reported after liver transplantation including the patient who was confirmed with recurrence. Conclusions: Our finding demonstrated that neo-adjuvant gemcitabine and cisplatin with no radiation prior to liver transplantation resulted in excellent outcomes for patients with cholangiocarcinoma.

Utilization of Immunotherapy for the Treatment of Hepatocellular Carcinoma in the Peri-Transplant Setting: Transplant Oncology View

Simple Summary

Hepatocellular carcinoma is the second most common cause of cancer-related deaths and accounts for over eighty percent of primary liver cancers worldwide. Regarding the Milan Criteria, only a small portion of HCC patients are eligible for liver transplantation due to advanced-stage disease and large tumor size preventing/delaying organ allocation. Recently, the use of anti-programmed cell death protein 1 and programmed cell death ligand 1 (PD-1 and PD-L1) checkpoint inhibitors in the treatment of cancers have evolved rapidly and these therapies have been approved for the treatment of HCC, however, the main concerns about organ rejection in liver transplant patients who will be treated with ICPIs are still the same in both pre-and post-transplant setting. To alleviate those concerns, more global collaborations to explore the safety and efficacy of ICPIs in both the pre-and post-organ transplantation settings are required. The decision to administer ICPI treatment in liver transplant patients should be made on a case-by-case basis according to the goal of care and the availability and efficacy of other treatment options.

Abstract

Hepatocellular carcinoma (HCC) represents the second most common cause of cancer-related deaths and accounts for over eighty percent of primary liver cancers worldwide. Surgical resection and radiofrequency ablation in small tumors are included in the treatment options for HCC patients with good liver function profiles. According to the Milan Criteria, only a small portion of HCC patients are eligible for liver transplantation due to advanced-stage disease and large tumor size preventing/delaying organ allocation. Recently, the use of anti-programmed cell death protein 1 and programmed cell death ligand 1 (PD-1 and PD-L1) checkpoint inhibitors in the treatment of cancers have evolved rapidly and these therapies have been approved for the treatment of HCC. Immune checkpoint inhibitors have resulted in good clinical outcomes in pre-and post-transplant HCC patients, although, some reports showed that certain recipients may face rejection and graft loss. In this review, we aim to illustrate and summarize the utilization of immune checkpoint inhibitor therapies in pre-and post-liver transplants for HCC patients and discuss the assessment of immune checkpoint inhibitor regulators that might determine liver transplant outcomes.