Liver Transplantation for Cholangiocarcinoma: Insights into the Prognosis and the Evolving Indications

Contemporary trends and outcomes after liver transplantation and resection for intrahepatic cholangiocarcinoma

BACKGROUND

Liver transplantation (LT) has been shown to be superior to resection in highly selected patients with perihilar cholangiocarcinoma (CCA), yet has traditionally been contraindicated for intrahepatic CCA (iCCA). Herein, we aimed to examine contemporary trends and outcomes for surgical resection and LT for iCCA.

METHODS

The National Cancer Database was queried for patients presenting with stage I-III iCCA between 2010 and 2018 who underwent resection or LT. Overall survival (OS) was compared with Kaplan-Meier and multivariable Cox proportional hazards methods stratified by management. Secondary analysis of patients undergoing transplant for CCA was performed with the United Network for Organ Sharing database.

RESULTS

Of 2565 patients, 2412 (94.0%) underwent resection and 153 (5.96%) LT of whom 84 (54.9%) received neoadjuvant therapy. Utilization of LT remained between 3.9% and 7.8% annually. Unadjusted 5-year OS was higher for LT than resection (59.8% vs 39.9%, P = .0067), yet adjusted analysis revealed no significant difference in mortality (hazard ratio, 0.91; 95% CI, 0.66-1.27; P = .58). On secondary analysis including 437 patients with all subtypes of CCA, unadjusted 5-year OS was higher for non-CCA indications (79% vs 52%-54%, P < .001).

CONCLUSION

Utilization of LT for iCCA remains low and many cases are likely incidental. Although partial hepatectomy remains the standard of care for patients with resectable disease, our findings suggest that highly selected patients with unresectable iCCA may achieve favorable outcomes after LT. Granular, prospective data are needed to identify patients most likely to benefit from transplant and allocate scarce liver grafts.

Liver Transplant for Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCCA) tends to be asymptomatic until late stages, leading most of the patients to present at advanced stages of the disease. A combination of medical and surgical therapy is crucial for patient management. Historically, poor outcomes resulted in liver transplantation being formally contraindicated for patients with iCCA; however, recent advances in patient selection and neoadjuvant therapy have resulted in a paradigm shift in liver transplant oncology. As a result, the feasibility of liver transplantation for iCCA is being reevaluated by several centers as a therapeutic alternative for select patients with locally advanced unresectable disease.

Unique Morphologic Findings in the Liver After Stereotactic Radiation for Cholangiocarcinoma

Newer radiotherapy techniques, such as stereotactic body radiation, have been increasingly used as part of the treatment of cholangiocarcinomas, particularly as a bridge to liver transplantation. Although conformal, these high-dose therapies result in tissue injury in the peritumoral liver tissue. This retrospective study characterized the morphologic changes in the liver after stereotactic body radiation in a series of liver explant specimens with perihilar cholangiocarcinoma. The morphologic changes in the irradiated zone were compared against the nonirradiated background liver parenchyma to control for chemotherapy-related changes. Of the 21 cases studied, 16 patients (76.2%) had underlying primary sclerosing cholangitis, and 13 patients (61.9%) had advanced liver fibrosis. The average duration between completion of radiotherapy and liver transplantation was 33.4 weeks (range: 6.29 to 67.7). Twelve patients (57.1%) had no residual tumor in the liver. The most frequent histologic changes in the peritumoral irradiated liver tissue were sinusoidal congestion (100%), sinusoidal edematous stroma (100%), and hepatocellular atrophy (100%), followed by partial/complete occlusion of central veins (76.2%), sinusoidal cellular infiltrates (76.2%), and hepatocyte dropout (66.7%). The findings in the radiated areas were more extensive than in the background liver ( P <0.01). Sinusoidal edematous stroma was striking and dominated the histologic findings in some cases. Over time, there was less sinusoidal congestion but more hepatocyte dropout (r s =-0.54, P =0.012 and r s =0.64, P =0.002, respectively). Uncommon findings, such as foam cell arteriopathy in the liver hilum, were also observed. In summary, postradiation liver specimens have distinctive morphologic findings.

Evaluating the Significance of Pancreatobiliary Fluorescence In Situ Hybridization Polysomy on Prognosis in De Novo Cholangiocarcinoma

INTRODUCTION

We recently developed a fluorescence in situ hybridization probe set for evaluating suspicious biliary and pancreatic duct strictures (PB-FISH). We aimed to determine whether PB-FISH results in biliary brush cytology specimens are associated with outcomes of patients with cholangiocarcinoma (CCA).

METHODS

We performed a retrospective study of patients with CCA tested by PB-FISH from January 2015 to August 2018. CCA was stratified by primary sclerosing cholangitis (PSC) into those with (PSC CCA) or without PSC ( de novo CCA). PB-FISH results were categorized as polysomy (gain of multiple loci), nonpolysomy (single locus gain, single locus gain with 9p21 loss, homozygous 9p21 loss, tetrasomy), and disomy (no abnormalities). Overall survival (OS) was estimated using Kaplan-Meier methods and compared between the PB-FISH results using log-rank tests. Cox models were adjusted for age, sex, CA 19-9, cytology results, source of brushing sample, and treatments.

RESULTS

Characteristics of 264 eligible patients (median age 60.4; range 18-92) were comparable for patients with PB-FISH polysomy vs nonpolysomy vs disomy. The median OS was similar between disomy, nonpolysomy, and polysomy in the overall population (22.7 vs 22.7 vs 20.3 months, respectively). For de novo CCA, both polysomy and nonpolysomy were associated with worse OS compared with disomy (polysomy: hazard ratio [HR] = 2.09, 95% confidence interval [CI] = 1.14-3.83; nonpolysomy: HR = 2.4, 95% CI = 0.54-2.46; P = 0.027). For PSC CCA, neither polysomy nor nonpolysomy were significantly associated with worse OS (polysomy: 0.90, 95% CI = 0.47-1.75; nonpolysomy: HR = 1.78, CI = 0.71-4.49; P = 0.27).

DISCUSSION

PB-FISH alterations are associated with worse survival in de novo CCA, though statistical significance was lost when adjusting for confounding variables.

Review of incidence and outcomes of treatment of cholangiocarcinoma in patients with primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a premalignant condition and a well-documented risk factor for cholangiocarcinoma (CCA) which is the most common malignancy in this setting and the leading cause of deaths in the recent years, with an increasing incidence. PSC-associated CCA has a geographical distribution that follows the incidence of PSC, with an observed ascending gradient from the Eastern to the Western and from the Southern to the Northern countries. It may arise at any location along the biliary tree but is most common in the perihilar area. Patients with PSC and intrahepatic or perihilar CCA are typically not suitable for liver resection, which is otherwise the treatment of choice with curative intent in patients with resectable tumours, providing a radical resection with clear margins can be achieved. This largely relates to the commonly advanced stage of liver disease at presentation, which allows consideration for liver resection only for a very limited number of suitable patients with PSC. On the other hand, remarkable progress has been reached in the last decades with the implementation of a protocol combining neoadjuvant chemoradiation and orthotopic liver transplantation (OLT) for the treatment of perihilar CCA, within specific criteria. Excellent results have been achieved particularly for PSC patients with this cancer, who seem to benefit the most from this treatment, having converted this into an accepted indication for transplantation and the standard of care in several experienced centres. Intrahepatic CCA as an indication for OLT remains controversial and has not been accepted given disappointing previous results. However, as recent studies have shown favourable outcomes in early intrahepatic CCA, it may be that under defined criteria, OLT may play a more prominent role in the future. Distal CCA in the context of PSC requires aggressive surgical treatment with curative intent, when feasible. This review provides insight about particular features of CCA in the setting of PSC, with a main focus on its incidence, considerations relating to its anatomical location and implications to treatment and outcomes, through the viewpoint of historical evolution of management, and future perspectives.

The Role of Surgical Resection and Liver Transplantation for the Treatment of Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCCA) is a rare and complex malignancy of the biliary epithelium. Due to its silent presentation, patients are frequently diagnosed late in their disease course, resulting in poor overall survival. Advances in molecular profiling and targeted therapies have improved medical management, but long-term survival is rarely seen with medical therapy alone. Surgical resection offers a survival advantage, but negative oncologic margins are difficult to achieve, recurrence rates are high, and the need for adequate future liver remnant limits the extent of resection. Advances in neoadjuvant and adjuvant treatments have broadened patient treatment options, and these agents are undergoing active investigation, especially in the setting of advanced, initially unresectable disease. For those who are not able to undergo resection, liver transplantation is emerging as a potential curative therapy in certain cases. Patient selection, favorable tumor biology, and a protocolized, multidisciplinary approach are ultimately necessary for best patient outcomes. This review will discuss the current surgical management of locally advanced, liver-limited intrahepatic cholangiocarcinoma as well as the role of liver transplantation for select patients with background liver disease.

Expanding indications for liver transplantation in the era of liver transplant oncology

Despite numerous advances and emerging data, liver transplantation in the setting of gastrointestinal malignancies remains controversial outside of certain accepted indications. In an era of persistent organ shortage and increasing organ demand, allocation of liver grafts must be considered carefully. While hepatocellular carcinoma and hilar cholangiocarcinoma have become accepted indications for transplantation, tumor size and standardized multi-disciplinary treatment protocols are necessary to ensure optimal patient outcomes. As more studies seeking to expand the oncologic indications for liver transplantation are emerging, it is becoming increasingly clear that tumor biology and response to therapy are key factors for optimal oncologic outcomes. In addition, time from diagnosis to transplantation appears to correlate with survival, as stable disease over time portends better outcomes post-operatively. Identifying aggressive disease pre-transplant remains difficult with current imaging and tissue sampling techniques. While tumor size and stage are important prognostic predictors for most malignancies, patient and tumor selection protocols are necessary. As the fields of medical and surgical oncology continue to evolve, it is clear that a protocolized interdisciplinary treatment approach is necessary for combatting any cancer effectively. Disease stability over time and response to neoadjuvant therapy may be the best predictors for successful patient outcomes and can be easily incorporated in our treatment paradigms. Current data evaluating liver transplantation for expanded oncologic indications such as: expanded criteria hepatocellular carcinoma, intrahepatic cholangiocarcinoma, mixed tumors, and liver limited metastatic colorectal carcinomas, incorporate multi-modal therapies and evaluation of tumor treatment response. While further investigation is necessary, initial results suggest there is an expanded role for transplant surgery in malignancy in a new era of liver transplant oncology.

Analysis of metastasis and survival between extrahepatic and intrahepatic cholangiocarcinoma: A large population-based study

To date, extrahepatic cholangiocarcinoma (ECCA) and intrahepatic cholangiocarcinoma (ICCA) have rarely been compared; therefore, we attempted to learn more about the rates of metastasis and survival in both ICCA and ECCA.Data of patients in the SEER database diagnosed with ICCA or ECCA were extracted to analyse the rate of metastasis and survival. Univariate and multivariate logistic regression analyses were performed to identify the risk factors for metastasis. Propensity score matching (PSM) was used to compare survival rates between ECCA and ICCA.Data from a total of 15,751 patients diagnosed with ICCA or ECCA were extracted to analyse the rate of metastasis. Metastasis was more common in ECCA than ICCA (42.62% vs. 31.46%, P < .05), while ICCA in the T1 stage had a lower rate of metastasis (25.35% vs. 30.61%, P < .05). Age, pathology grade, tumour size, lymph node metastasis and T stage were independent risk factors for metastasis in both ECCA and ICCA. There was an inverse correlation between age and metastasis in both ICCA and ECCA. Moreover, PSM demonstrated that patients with ECCA had a better prognosis than patients with ICCA. Patients with ICCA in the T1 stage had better survival than those with ECCA in the T1 stage.Our study was the first to compare the rates of metastasis and survival between ECCA and ICCA. We observed an inverse association between age and metastasis, that patients with ECCA had a better prognosis than patients with ICCA, and that patients with ECCA in the T1 stage had worse survival than patients with ICCA in the T1 stage.

Neoadjuvant therapy for cholangiocarcinoma: A comprehensive literature review

Biliary tract cancers (BTCs) comprise a heterogenous group of aggressive and rare malignancies arising in the bile duct outside or within the liver. BTCs include cholangiocarcinoma (CCA), gallbladder cancer (GBC) and ampulla of Vater cancer (AVC); according to the "historical" anatomical classification, CCAs are further subdivided into extrahepatic cholangiocarcinomas (eCCAs) - including distal (dCCA) and perihilar (pCCA) - and intrahepatic cholangiocarcinomas (iCCA). Notably enough, these subtypes reflect distinct features in terms of biology, epidemiology, prognosis and therapeutic strategies. Although surgical resection remains the only potentially curative treatment option for CCA patients, radical surgery is possible for only a small proportion of cases. Moreover, it has been observed that up to 50% of patients deemed resectable at diagnosis are found to be unresectable during exploratory laparotomy. Additionally, even following radical surgery, recurrence rates are high. Neoadjuvant therapy represents an appealing approach in this setting, where this therapeutic strategy has the potential to improve local and distant control, to achieve R0 resection and to prevent distant metastasis. However, few data are currently available supporting neoadjuvant therapy in CCA and several questions remains unanswered, including the activity of systemic therapy in early stages of the disease, the optimal start time of treatment, patient selection and the length of neoadjuvant therapy. In this review, we will discuss available data on neoadjuvant systemic therapy in CCA, highlighting future directions in this setting, with a particular focus on recently published data and ongoing and recruiting trials.