Liver transplantation for cholangiocarcinoma: current best practice

Exosomal circular RNAs: A new frontier in the metastasis of digestive system tumors

Exosomes are membrane vesicles with a diameter of 30–150 nm. Exosomes are secreted by various types of tumor cell and contain a variety of proteins, circular RNAs (circRNAs), microRNAs and DNA, depending on the host cells. Among them, circRNAs, which are long non-coding endogenous RNAs, form covalently closed and continuous loops that link the 3′ and 5′ terminals generated by back-splicing. circRNAs have become a hotspot of research. Exosomal circRNAs are in volved in the pathogenesis of cancer, especially metastasis, which is mainly ascribed to the frequently abnormal expression levels within neoplasms. Nonetheless, the functions and regulatory mechanisms of exosomal circRNAs in the progression of digestive system tumors (DSTs) remain unclear. More knowledge on the regulation and network interactions of exosomal circRNAs will help identify superior treatment strategies for the metastasis of DSTs. The present review aims to summarize the existing studies on the functions and mechanisms of exosomal circRNAs in tumorigenesis, and evaluate the associations between the dysregulation of exosomal circRNAs and tumor metastasis.

Association Between Travel Distance, Hospital Volume, and Outcomes Following Resection of Cholangiocarcinoma

BACKGROUND

The objective of the current study was to characterize the association between travel distance/hospital volume relative to outcomes following resection of cholangiocarcinoma.

METHODS

Patients were identified using the 2004-2015 National Cancer Database and stratified into quartiles according to travel distance/hospital volume. Multivariable regression models were utilized to examine the impact of travel distance and hospital volume on quality-of-care metrics and overall survival.

RESULTS

Among 5125 patients, the majority of patients had T1/2 (N = 2006, 41.1%) and N0 disease (N = 2498, 50.9%). Median hospital quartile surgical volumes in cases/year were low volume (LV) 6, intermediate low volume (ILV) 7, intermediate high volume (IHV) 12, and high volume (HV) 24 cases/year. Median travel distance quartiles in miles were short travel (ST) 2.7, intermediate short travel (IST) 7.9, intermediate long travel (ILT) 18.9, and long travel (LT) 84.7. Longer travel distances were associated with better overall survival, as every 10 miles was associated with a 2% decrease in mortality (p = 0.02). Differences in quality-of-care metrics were largely mediated through travel distance.

CONCLUSIONS

Travel distance and hospital volume were associated with certain quality-of-care metrics among patients with cholangiocarcinoma. After controlling for hospital volume and travel distance simultaneously, only travel distance was associated with decreased risk of mortality.

Liver Transplant for Perihilar Cholangiocarcinoma (Klatskin Tumor): The Essential Role of Patient Selection

OBJECTIVES

Perihilar cholangiocarcinoma (Klatskin tumor) is a rare tumor entity, which is diagnosed late due to uncharacteristic symptoms. The therapeutic strategy for cure is still liver resection. Liver transplant in cases of locally irresectable tumors represents an alternative potential curative therapy for a select group of patients.

MATERIALS AND METHODS

We present our data of 22 patients with irresectable Klatskin tumors who received transplants between 1996 and 2015. We analyzed relevant prognostic factors for the selection of patients to be transplanted to ensure an acceptable overall survival and reviewed known and established selection criteria.

RESULTS

Four factors (age, tumor size, serum level of carbohydrate antigen 19-9, percutaneous transhepatic cholangiodrainage) could be detected for possible patient selection. Positive lymph node status and advanced tumor stage according to the Union for International Cancer Control were confirmed as negative prognostic factors for survival after transplant.

CONCLUSIONS

Liver transplant is a curative therapy for selected patients with irresectable Klatskin tumors, but further prospective studies are urgently needed.

Resection of the caudate lobe for the treatment of hilar cholangiocarcinoma

INTRODUCTION

Whether the resection of the caudate lobe, in association with major hepatectomy, improves outcomes in hilar cholangiocarcinoma is controversial.

EVIDENCE ACQUISITION

We performed a systematic literature review on all studies published from June 1979 to September 2016. Inclusion criteria for eligibility were the presence of parallel-groups of patients treated with major hepatectomy with either caudate lobe resection (CLR), or not (NCLR), in adult population, reporting data on overall survival (OS). We ran out a random-effect meta-analysis for survival data.

EVIDENCE SYNTHESIS

Six retrospective studies with 969 patients (643 CLR and 326 NCLR) were included. The probability of death was significantly lower in CLR group than in NCLR group (HR 0.65; 95% CI: 0.44-0.97; P=0.035). The median survival time was in favor of CLR (WMD 3.46; 95% CI: 1.02-5.90, P=0.005]. Patients who underwent CLR were more likely to receive a R0 resection than those who did not (OR 8.26; 95% CI: 2.45-27.87; P=0.001). No moderator effects were detected at meta-regression for operative time, postoperative complication rate and pathologic findings.

CONCLUSIONS

Despite the paucity of data and the retrospective nature of the included studies, our results suggest that major hepatectomy plus caudate lobe resection may improve the likelihood of R0 resection and the overall survival in patients with hilar cholangiocarcinoma.

Tumor Biology as Predictor of Mortality in Liver Transplantation for Hepatocellular Carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is the most frequent primary malignant liver tumor, with the Milan criteria considered to be the gold standard for patient selection for liver transplantation (LT).

MATERIALS AND METHODS

We performed a descriptive observational study, reviewing 20 years of experience of LT in patients with HCC in the Fundacion Valle del Lilí in Cali, Colombia. Subgroup analysis was undertaken for periods 1999 to 2007 and 2008 to 2015.

RESULTS

Fifty-seven cases with a pretransplant HCC diagnosis were reviewed. In the first period patients within the Milan criteria had a recurrence-free survival at 5 years of 66.6%, and in those who exceeded the Milan criteria, recurrence-free survival was 75%. In the second period, patients within the Milan criteria, recurrence-free survival at 5 years was 93.5%, and in those who exceeded the Milan criteria, recurrence-free survival was 75.7%. No statistically significant difference was found in either period. For patients with mild and moderate tumor differentiation, the relapse survival rate at 5 years was 69.4% (95% confidence interval [CI] 35.8-87.8) and 74.7% (95% CI 44.5-90), respectively. All patients with poor tumor differentiation relapsed and died within 3 years.

CONCLUSION

Global and recurrence-free survival among patients who met and patients who exceeded the Milan criteria was not significantly different, suggesting an expansion of the Milan criteria to include potential recipients who were previously excluded. Obtaining histologic differentiation and identifying vascular invasion will provide a more worthwhile contribution to LT decision making.

Multidisciplinary management of intrahepatic cholangiocarcinoma: Current approaches

Intrahepatic cholangiocarcinoma (ICC) is a common primary hepatic tumor. However, its outcomes are usually worse than those of hepatocellular carcinoma owing to its non-specific presentation and detection at an advanced stage. The most widely used serum marker, carbohydrate antigen 19-9, is non-specific. Furthermore, imaging studies rarely identify any pathognomonic features. Surgery is the only treatment option that offers a chance of long-term survival. However, the resectability rate is low owing to the high frequencies of intrahepatic metastases, peritoneal carcinomatosis, or extrahepatic metastases. Surgical treatment should be tailored according to the macroscopic classification of ICC (e.g. mass-forming, periductal infiltrating, and intraductal growth types) because it reflects the tumor's dissemination pattern. Although lymph node metastasis is a negative prognostic factor, the importance and extent of lymph node dissection is still controversial. To improve patient survival, liver transplantation is considered in some patients with unresectable ICC, especially in those with an insufficient remnant liver volume. Minimally invasive procedures, including laparoscopic and robotic liver resection, have been tested and achieved comparable outcomes to conventional surgery in preliminary studies. No randomized trials have confirmed the efficacy of adjuvant chemotherapy in ICC, and several trials have evaluated molecular-targeted agents as monotherapy or in combination with cytotoxic chemotherapy. Multidisciplinary approaches are necessary to improve the outcomes of ICC.

Intrahepatic cholangiocarcinoma: current perspectives

Intrahepatic cholangiocarcinoma (ICC) is the second most common malignancy arising from the liver. ICC makes up about 10% of all cholangiocarcinomas. It arises from the peripheral bile ducts within the liver parenchyma, proximal to the secondary biliary radicals. Histologically, the majority of ICCs are adenocarcinomas. Only a minority of patients (15%) present with resectable disease, with a median survival of less than 3 years. Multidisciplinary management of ICC is complicated by large differences in disease course for individual patients both across and within tumor stages. Risk models and nomograms have been developed to more accurately predict survival of individual patients based on clinical parameters. Predictive risk factors are necessary to improve patient selection for systemic treatments. Molecular differences between tumors, such as in the epidermal growth factor receptor status, are promising, but their clinical applicability should be validated. For patients with locally advanced disease, several treatment strategies are being evaluated. Both hepatic arterial infusion chemotherapy with floxuridine and yttrium-90 embolization aim to downstage locally advanced ICC. Selected patients have resectable disease after downstaging, and other patients might benefit because of postponing widespread dissemination and biliary obstruction.

Prognostic Significance of the Histologic Response of Perihilar Cholangiocarcinoma to Preoperative Neoadjuvant Chemoradiation in Liver Explants

Perihilar cholangiocarcinoma (pCCA) has a dismal prognosis. Protocols incorporating chemotherapy, radiotherapy, and liver transplantation (LT) have emerged as curative options for unresectable tumors with 70% 5-year survival rates. We aimed to assess the value of extent of residual tumor (ERT) and other pathologic factors following chemoradiation in predicting outcome; 152 liver explants with pCCA treated with neoadjuvant chemoradiation and LT between 1993 and 2013 were reviewed for ERT, pathologic stage, histologic grade, and perineural and lymphovascular invasion. ERT was quantified as the percentage of viable carcinoma in the tumor bed. Tumors were classified into 4 ERT categories: (1) complete/near-complete response (≤1% ERT); (2) marked response (>1 to <10% ERT); (3) moderate response (10 to <30% ERT); and (4) minimal response (≥30% ERT). Overall 5-year survival rate was 69%. 5-year disease-free estimate was 74%. 57%, 16%, 18%, and 9% of explants were placed in ERT categories 1, 2, 3, and 4, respectively. ERT correlated significantly with the overall 5-year survival rate and 5-year, disease-free estimate by univariate (P<0.0001) and multivariate analysis (P=0.004 and 0.009, respectively). By multivariate analysis, pathologic stage was also an independent predictor of recurrence (P=0.003). Other variables that correlated with risk of death and recurrence by univariate analysis included perineural (P<0.0001) and lymphovascular invasion (P<0.0001), absence of primary sclerosing cholangitis (P=0.006 and P<0.0001, respectively), and pretreatment CA19-9 level (P=0.001 and 0.02, respectively). Histologic grade did not predict outcome. In summary, ERT independently predicts outcome in pCCA patients following neoadjuvant chemoradiation and LT and can stratify patient prognosis.

Cholangiocarcinoma: Current opinion on clinical practice diagnostic and therapeutic algorithms: A review of the literature and a long-standing experience of a referral center

In the oncology landscape, cholangiocarcinoma is a challenging disease in terms of both diagnosis and treatment. Besides anamnesis and clinical examination, a definitive diagnosis of cholangiocarcinoma should be supported by imaging techniques (US, CT, MRI) and invasive investigations (ERC or EUS with brushing and FNA or US or CT-guided biopsy) followed by pathological confirmation. Surgery is the main curative option, so resectability of the tumour should be promptly assessed. Moreover, jaundice must be evaluated at the outset because biliary tract decompression with drainage and stent placement may be required. If the patient is resectable, pre-operative assessment of postoperative liver function is mandatory. After a curative resection, an adjuvant therapy may be administered. Otherwise, in cases with macroscopic residual disease after surgery or locally recurrent or unresectable cholangiocarcinoma at the diagnosis, first-line chemotherapy is the preferred strategy, possibly associated with radiotherapy and/or locoregional treatments. As the diagnostic and therapeutic pathway for cholangiocarcinoma can be declined in different modalities, patients should be promptly referred to a multidisciplinary team in a tertiary centre, familiar with this rare but lethal disease. Hence, the aim of the present paper is to focus on diagnostic and therapeutic algorithms based on the common guidelines and also on the clinical practice of multispecialist expert groups.

Volatile Organic Compounds in Urine for Noninvasive Diagnosis of Malignant Biliary Strictures: A Pilot Study

BACKGROUND

The use of volatile organic compounds (VOCs) in bile was recently studied and appeared promising for diagnosis of malignancy. Noninvasive diagnosis of malignant biliary strictures by using VOCs in urine has not been studied.

AIM

To identify potential VOCs in urine to diagnose malignant biliary strictures.

METHODS

In this prospective cross-sectional study, urine was obtained immediately prior to ERCP from consecutive patients with biliary strictures. Selected-ion flow-tube mass spectrometry was used to analyze the concentration of VOCs in urine samples.

RESULTS

Fifty-four patients with biliary strictures were enrolled. Fifteen patients had malignant stricture [six cholangiocarcinoma (CCA) and nine pancreatic cancer], and 39 patients had benign strictures [10 primary sclerosing cholangitis (PSC) and 29 with benign biliary conditions including chronic pancreatitis and papillary stenosis]. The concentration of several compounds (ethanol and 2-propanol) was significantly different in patients with malignant compared with benign biliary strictures (p < 0.05). Using receiver operating characteristic curve analysis, we developed a model for the diagnosis of malignant biliary strictures adjusted for age and gender based on VOC levels of 2-propranol, carbon disulfide, and trimethyl amine (TMA). The model [-2.4191 * log(2-propanol) + 1.1617 * log(TMA) - 1.2172 * log(carbon disulfide)] ≥ 7.73 identified the patients with malignant biliary stricture [area under the curve (AUC = 0.83)], with 93.3 % sensitivity and 61.5 % specificity (p = 0.009). Comparing patients with CCA and PSC, the model [38.864 * log(ethane) - 3.989 * log(1-octene)] ≤ 169.9 could identify CCA with 80 % sensitivity and 100 % specificity (AUC = 0.9).

CONCLUSIONS

Measurement of VOCs in urine may diagnose malignant biliary strictures noninvasively.

MRI of cholangiocarcinoma

Cholangiocarcinomas are the second most common primary hepatobiliary tumors after hepatocellular carcinomas. They can be categorized either based on their location (intrahepatic/perihilar/extrahepatic distal) or their growth characteristics (mass-forming/periductal-infiltrating/intraductal) because they exhibit varied presentations and outcomes based on their location and or pattern of growth. The increased risk of cholangiocarcinoma in PSC necessitates close surveillance of these patients by means of imaging and laboratory measures; and because currently surgical resection is the only effective treatment for cholangiocarcinoma, the need for accurate pre-operative staging and assessment of resectability has emphasized the role of high quality imaging in management. Today magnetic resonance imaging (MRI) is the modality of choice for detection, pre-operative staging and surveillance of cholangiocarcinoma.