Cholangiocarcinoma is associated with a raised enhanced liver fibrosis score independent of primary sclerosing cholangitis

Cholangiocarcinoma: The era of liquid biopsy

Cholangiocarcinoma (CCA) is a highly aggressive and heterogeneous malignancy arising from the epithelial cells of the biliary tract. The limitations of the current methods in the diagnosis of CCA highlight the urgent need for new, accurate tools for early cancer detection, better prognostication and patient monitoring. Liquid biopsy (LB) is a modern and non-invasive technique comprising a diverse group of methodologies aiming to detect tumour biomarkers from body fluids. These biomarkers include circulating tumour cells, cell-free DNA, circulating tumour DNA, RNA and extracellular vesicles. The aim of this review is to explore the current and potential future applications of LB in CCA management, with a focus on diagnosis, prognostication and monitoring. We examine both its significant potential and the inevitable limitations associated with this technology. We conclude that LB holds considerable promise, but further research is necessary to fully integrate it into precision oncology for CCA.

Primary Sclerosing Cholangitis-Associated Cholangiocarcinoma: From Pathogenesis to Diagnostic and Surveillance Strategies

Cholangiocarcinoma (CCA) is the most common malignancy in patients with primary sclerosing cholangitis (PSC), accounting for 2-8% of cases and being the leading cause of death in these patients. The majority of PSC-associated CCAs (PSC-CCA) develop within the first few years after PSC diagnosis. Older age and male sex, as well as concomitant inflammatory bowel disease (IBD) or high-grade biliary stenosis, are some of the most relevant risk factors. A complex combination of molecular mechanisms involving inflammatory pathways, direct cytopathic damage, and epigenetic and genetic alterations are involved in cholangiocytes carcinogenesis. The insidious clinical presentation makes early detection difficult, and the integration of biochemical, radiological, and histological features does not always lead to a definitive diagnosis of PSC-CCA. Surveillance is mandatory, but current guideline strategies failed to improve early detection and consequently a higher patient survival rate. MicroRNAs (miRNAs), gene methylation, proteomic and metabolomic profile, and extracellular vesicle components are some of the novel biomarkers recently applied in PSC-CCA detection with promising results. The integration of these new molecular approaches in PSC diagnosis and monitoring could contribute to new diagnostic and surveillance strategies.

Noninvasive prognostic models, imaging, and elastography to predict clinical events in primary sclerosing cholangitis: A review

Surrogate endpoints are needed to estimate clinical outcomes in primary sclerosing cholangitis (PSC). Serum alkaline phosphatase was among the first markers studied, but there is substantial variability in alkaline phosphatase levels during the natural history of PSC without intervention. The Mayo risk score incorporates noninvasive variables and has served as a surrogate endpoint for survival for more than two decades. Newer models have better test performance than the Mayo risk score, including the primary sclerosing risk estimate tool (PREsTo) model and UK-PSC score that estimate hepatic decompensation and transplant free survival, respectively. The c-statistics for transplant-free survival for the Mayo risk model and the long-term UK-PSC model are 0.68 and 0.85, respectively. The c-statistics for hepatic decompensation for the Mayo risk model and PREsTo model are 0.85 and 0.90, respectively. The Amsterdam-Oxford model included patients with large duct and small duct PSC and patients with PSC-autoimmune hepatitis overlap and had a c-statistic of 0.68 for transplant-free survival. Other noninvasive tests that warrant further validation include magnetic resonance imaging, elastography and the enhanced liver fibrosis score. Prognostic models, noninvasive tests or a combination of these surrogate endpoints may not only serve to be useful in clinical trials of investigational agents, but also serve to inform our patients about their prognosis.

Blood-based tumor fibrosis markers as diagnostic and prognostic biomarkers in patients with biliary tract cancer

Biliary tract cancer (BTC) is characterized by a desmoplastic extracellular matrix (ECM). We tested the diagnostic and prognostic use of seven circulating biomarkers of ECM remodeling: pro-peptides of type III collagen (PRO-C3), VI (PRO-C6) and XI (PRO-C11), matrix metalloprotease (MMP) degraded type III collagen (C3M) and type IV collagen (C4M) fragments, granzyme B degraded type IV collagen fragments (C4G) and MMP degraded and citrullinated vimentin (VICM) a marker of macrophage activation. The study included 269 patients with all stages of BTC and 49 patients with benign biliary tract diseases. Serum samples from BTC patients were collected before surgery, or before first- or second-line chemotherapy. C3M, C4M, PRO-C3, PRO-C6, PRO-C11 and VICM levels were elevated in patients with BTC compared to patients with benign disease. Receiver operating characteristics curve analyses identified PRO-C3 (area under curve [AUC] = 0.87) as the ECM marker with the best diagnostic performance. The ECM biomarkers correlated with inflammation biomarkers (C-reactive protein [CRP], interleukin-6 [IL-6] and YKL-40) but not with CA19-9. To investigate prognostic performance, patients were split into three cohorts (first-line, second-line and surgery). Elevated ECM biomarker levels were associated with short overall survival (OS), but only pretreatment PRO-C3 and PRO-C6 were associated with OS in both the first-line and second-line settings when adjusting for CA19-9, performance status and stage in a multivariate Cox-regression analyses. Our results indicate that collagen remodeling is increased in patients with BTC and associated with survival. The collagen pro-peptides (PRO-C3 and PRO-C6) could be used as novel biomarkers in these patients.

Prognostic modeling in biliary diseases

PURPOSE OF REVIEW

To discuss the prognostic models for the cholestatic diseases focusing on primary sclerosing cholangitis and primary biliary cholangitis.

RECENT FINDINGS

Noninvasive prognostic models that outperform alkaline phosphatase and Mayo Risk Score have been developed to predict clinically significant events, such as transplant free survival or hepatic decompensation. Models for primary sclerosing cholangitis (PSC) include UK-PSC, Primary Sclerosing Cholangitis Risk Estimate Tool, and Amsterdam Oxford models. Models for primary biliary cirrhosis (PBC) include UK-PBC, Global primary biliary cholangitis group score (GLOBE) and Paris II scores. Other models have incorporated elastography with or without findings on magnetic resonance imaging.

SUMMARY

Noninvasive prognostic models can inform patients about their risk for clinical outcomes and serve as surrogate intermediate outcomes to determine efficacy of novel agents in clinical trials.

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.

Systematic Review of Prognostic Models Compared to the Mayo Risk Score for Primary Sclerosing Cholangitis

Background: Primary sclerosing cholangitis (PSC) is a cholestatic liver disease with a variable clinical course that can ultimately lead to end-stage liver disease, cholangiocarcinoma, and the need for liver transplantation. Several prognostic models have been developed to predict clinical outcomes and have been compared to the revised Mayo Risk Score (rMRS). Aim: To conduct a systematic review comparing the rMRS to other non-invasive prognostic tests for PSC. Methods: A systematic review of studies from 2000 to 2020 was performed that compared non-invasive biochemical prognostic models to the rMRS in predicting outcomes in patients with PSC. Results: Thirty-seven studies were identified, of which five studies that collectively included 3230 patients were reviewed. Outcomes included transplant-free survival or composite clinical outcomes. The rMRS was better than the Amsterdam–Oxford model for predicting 1-year transplant-free survival, c-statistics 0.75 and 0.70, respectively. The UK-PSC score outperformed the rMRS for 10-year transplant-free survival, c-statistics 0.85 and 0.69, respectively. An enhanced liver fibrosis score was independently associated with transplant-free survival after adjusting for rMRS. PREsTo predicts 5-year hepatic decompensation with a c-statistic modestly higher than rMRS; 0.90 and 0.85, respectively. Conclusion: Newer prognostic models, including the UK-PSC score and PREsTo, are more accurate at predicting clinical endpoints in PSC compared to the rMRS. Time frames and clinical endpoints are not standard among studies.

Advances in the clinical use of collagen as biomarker of liver fibrosis

INTRODUCTION

Hepatic fibrosis is the excessive synthesis and deposition of extracellular matrix including collagen in the tissue. Chronic liver insult leads to progressive parenchymal damage, portal hypertension, and cirrhosis. Determination of hepatic collagen by invasive liver biopsy is the gold standard to estimate severity and stage of fibrosis. However, this procedure is associated with pain, carries the risk of infection and bleeding, and is afflicted with a high degree of sampling error. Therefore, there is urgent need for serological collagen-derived markers to assess collagen synthesis/turnover.

AREAS COVERED

Biochemical properties of collagens, cellular sources of hepatic collagen synthesis, and regulatory aspects in collagen expression. Markers are discussed suitable to estimate hepatic collagen synthesis and/or turnover. Discussed studies were identified through a PubMed search done in May 2020 and the authors' topic knowledge.

EXPERT OPINION

Hepatic fibrosis is mainly characterized by accumulation of collagen-rich scar tissue. Although traditionally performed liver biopsy is still standard in estimating hepatic fibrosis, there is evidence that noninvasive diagnostic scores and collagen-derived neo-epitopes provide clinical useful information. These noninvasive tests are less expensive than liver biopsy, better tolerated, safer, and more acceptable to patients. Therefore, these tests will lead to dramatic changes in diagnosis.

Detecting cholangiocarcinoma in patients with primary sclerosing cholangitis - The promise of DNA methylation and molecular biomarkers

Cholangiocarcinoma (CCA) is a highly fatal malignancy of the bile ducts that arises in up to 20% of patients with primary sclerosing cholangitis (PSC). Current detection methods for CCA display suboptimal sensitivity and/or specificity, and there is no evidence-based screening strategy for CCA in patients with PSC. Consequently, CCA is often detected too late for surgical resection, contributing to the high mortality associated with this malignancy. Recently, biomarkers have emerged with potential to complement current detection methods, and/or be used for cancer surveillance in high-risk patient groups, including patients with PSC. Aberrant DNA methylation patterns represent promising biomarkers with great potential for CCA detection. Such aberrations are frequent in CCA, often occur early, and can be detected in liquid biopsies, including blood, bile and urine. This review summarises and highlights the most promising DNA methylation biomarkers identified for CCA detection so far, focusing on patients with PSC. Other promising molecular biomarkers for detection of PSC-associated CCA in liquid biopsies will also be briefly covered.

Cancer risk, screening and surveillance in primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a rare chronic inflammatory condition mainly of the large bile ducts, affecting predominantly young men, and is associated with the presence of inflammatory bowel disease. There is no known cure for PSC, which progresses to cirrhosis or death over 10-20 years. Hepatobiliary malignancy, especially cholangiocarcinoma, is a feared complication associated with poor overall survival. Screening and surveillance appear to improve overall outcomes. To capture as many relevant studies, broad search criteria were employed within the PubMed database. Given the high prevalence of IBD and its own associations with the development of malignancy two separate search strategies were employed. Results were filtered by English language. The first search identified the risks, epidemiological factors and surveillance strategies for patients with PSC at risk for developing malignancy. MeSH terms included: cholangitis, sclerosing, digestive system neoplasms, liver neoplasms, biliary tract neoplasms, cholangiocarcinoma, gallbladder neoplasms, colonic neoplasms, rectal neoplasms, or pancreatic neoplasms, risk factors, risk, surveillance, epidemiology and screen. The second included inflammatory bowel diseases, Crohn's, or colitis, and assessed for additional malignancies such as lymphoma and skin neoplasms. A total of 288 results returned with 21 duplicates; 267 remaining abstracts were assessed for relevance for inclusion by the authors. Patients with PSC show significantly higher than average risk for the development of hepatobiliary and colonic malignancies including cholangiocarcinoma, gallbladder carcinoma and colorectal carcinoma. Yearly ultrasound surveillance followed with more definitive cross-sectional imaging is prudent to arrive in a timely diagnosis of carcinoma, reducing morbidity and mortality.