Validation of the Mayo Clinic Staging System in Determining Prognoses of Patients With Perihilar Cholangiocarcinoma

Revealing the Heterogeneity of the Tumor Ecosystem of Cholangiocarcinoma through Single-Cell Transcriptomics

The prognosis of cholangiocarcinoma remains poor. The heterogeneity of the tumor ecosystem of cholangiocarcinoma plays a critical role in tumorigenesis and therapeutic resistance, thereby affecting the clinical outcome of patients with cholangiocarcinoma. Recent progress in single-cell RNA sequencing (scRNA-seq) has enabled detailed characterization of intratumoral stromal and malignant cells, which has vastly improved our understanding of the heterogeneity of various cell components in the tumor ecosystem of cholangiocarcinoma. It also provides an unprecedented view of the phenotypical and functional diversity in tumor and stromal cells including infiltrating immune cells. This review focuses on examining tumor heterogeneity and the interaction between various cellular components in the tumor ecosystem of cholangiocarcinoma derived from an scRNA-seq dataset, discussing limitations in current studies, and proposing future directions along with potential clinical applications.

Success, complication, and mortality rates of initial biliary drainage in patients with unresectable perihilar cholangiocarcinoma

BACKGROUND

The patients with unresectable perihilar cholangiocarcinoma require biliary drainage to relieve symptoms and allow for palliative systemic chemotherapy. The aim of this study was to establish the success, complication, and mortality rates of the initial biliary drainage in patients with unresectable perihilar cholangiocarcinoma at presentation.

METHODS

In this retrospective multicenter study, patients with unresectable perihilar cholangiocarcinoma who underwent initial endoscopic or percutaneous transhepatic biliary drainage between 2002 and 2014 were included. The success of drainage was defined as a successful biliary stent or drain placement, no unscheduled reintervention within 14 days, and serum bilirubin levels <50 μmol/L (ie, 2.9 mg/dL) or a >50% decrease in serum bilirubin after 14 days. Severe complications, and 90-day mortality were recorded.

RESULTS

Included were 186 patients: 161 (87%) underwent initial endoscopic biliary drainage and 25 (13%) underwent initial percutaneous transhepatic biliary drainage. The success of initial drainage was observed in 73 patients (45%) after endoscopic biliary drainage and 6 (24%) after percutaneous transhepatic biliary drainage. The reasons for an unsuccessful initial drainage were: the failure to place a drain or stent in 39 patients (21%), an unplanned reintervention within 14 days in 52 patients (28%), and the bilirubin level >50 μmol/L (or not halved) after 14 days of initial drainage in 16 patients (9%). Severe drainage-related complications occurred in 19 patients (12%) after endoscopic biliary drainage and in 3 (12%) after percutaneous transhepatic biliary drainage. Overall, 66 patients (36%) died within 90 days after initial biliary drainage.

CONCLUSION

Initial biliary drainage in patients with unresectable perihilar cholangiocarcinoma had a success rate of 45% and a 90-day mortality rate of 36%. Future studies for patients with perihilar cholangiocarcinoma should focus on improving biliary drainage.

Modification of the eighth AJCC/UICC staging system for perihilar cholangiocarcinoma: An alternative pathological staging system from cholangiocarcinoma-prevalent Northeast Thailand

Aim

This study aims to improve the classification performance of the eighth American Joint Committee on Cancer (AJCC) staging system for perihilar cholangiocarcinoma (pCCA) by proposing the Khon Kaen University (KKU) staging system developed in cholangiocarcinoma-prevalent Northeast Thailand.

Method

Four hundred eighty-eight patients with pCCA who underwent partial hepatectomy between 2002 and 2017 at the Srinagarind Hospital, Faculty of Medicine, Khon Kaen University, Thailand, were included. Overall survival (OS) related to clinicopathological features was analyzed using the Kaplan–Meier method. Logrank test was performed in univariate analysis to compare OS data of clinicopathological features to determine risk factors for poor survival. Significant features were further analyzed by multivariate analysis (Cox regression) to identify prognostic factors which were then employed to modify the eighth AJCC staging system.

Results

Multivariate analysis showed that growth pattern (HR = 4.67–19.72, p &lt; 0.001), moderately and poorly differentiated histological grades (HR = 2.31–4.99, p &lt; 0.05 and 0.001, respectively), lymph node metastasis N1 and N2 (HR = 1.37 and 2.18, p &lt; 0.05 and 0.01, respectively), and distant metastasis (HR = 2.11, p &lt; 0.001) were independent factors when compared to their respective reference groups. There was a clear separation of patients with pCCA into KKU stage: I [OS = 116 months (mo.)], II (OS = 46 mo.), IIIA (OS = 24 mo.), IIIB (11 mo.), IVA (OS = 7 mo.), and IVB (OS = 6 mo.).

Conclusion

The new staging system was based on the incorporation of growth patterns to modify the eighth AJCC staging system. The classification performance demonstrated that the KKU staging system was able to classify and distinctly separate patients with pCCA into those with good and poor outcomes. It was also able to improve the stratification performance and discriminative ability of different stages of pCCA classification better than the eighth AJCC staging system. Hence, the KKU staging system is proposed as an alternative model to augment the accuracy of survival prognostication and treatment performance for patients with pCCA.

Liver Transplant for Non-Hepatocellular Malignancies: A Review for Radiologists

Although traditionally only performed for hepatocellular carcinoma (HCC), the last decade has seen a resurgence in the use of liver transplant (LT) for non-HCC malignancies, likely due to improvements in neoadjuvant treatment regimens as well as the establishment of well-defined eligibility criteria. Given promising survival results, patients with perihilar cholangiocarcinoma, neuroendocrine liver metastases, and hepatic hemangioendothelioma are eligible to receive Model for End Stage Liver Disease (MELD) exception for tumors that meet well-defined criteria. Additional tumors such as colorectal cancer liver metastases, intrahepatic cholangiocarcinoma, and hepatocholangiocarcinoma may undergo transplant at specialized centers with well-defined protocols, although are not yet eligible for MELD exception. Transplant eligibility criteria commonly incorporate imaging findings, yet due to the relatively novel and evolving nature of LT for non-HCC malignancies, radiologists may be unaware of relevant criteria or of the implications of their imaging interpretations. Knowledge of the allocation process, background, and liver transplant selection criteria facilitates the radiologist' active participation in multidisciplinary discussion, leading to better and more equitable care for transplant candidates with non-HCC malignancy. This review provides an overview of transplant allocation and selection criteria in patients with non-HCC malignancy, with an emphasis on imaging features and the role of the radiologist.

Current status of liver transplantation for cholangiocarcinoma

Cholangiocarcinoma (CCA) is the second most common liver cancer with a median survival of 12-24 mo without treatment. It is further classified based on its location into intrahepatic CCA (iCCA), perihilar CCA (pCCA), and distal CCA. Surgical resection is the mainstay of treatment, but up to 70% of these tumors are inoperable at the time of diagnosis. CCA was previously an absolute contraindication for liver transplantation (LT) due to poor outcomes primary due to early recurrent disease. However, improvement in patient selection criteria and neoadjuvant treatment protocols have improved outcomes for inoperable pCCA patients with recent studies reporting LT may improve survival in iCCA. Future advances in the treatment of CCA should include refining patient selection criteria and organ allocation for all subtypes of CCA, determining effective immunotherapies and the evolving role of personalized medicine in patients ineligible for surgical resection or LT. Our article reviews the current status of LT in CCA, along with future directions in managing patients with CCA.

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.

Liver Transplantation for Cholangiocarcinoma and Mixed Hepatocellular Cholangiocarcinoma: Working Group Report From the ILTS Transplant Oncology Consensus Conference

Liver transplantation for cholangiocarcinoma has been an absolute contraindication worldwide due to poor results. However, in recent years and thanks to improvements of patient management and treatments of this cancer, this indication has been revisited. This consensus paper, approved by the International Liver Transplant Society, aims to provide a collection of expert opinions, consensus, and best practices surrounding liver transplantation for cholangiocarcinoma.

Evaluation of the New American Joint Committee on Cancer Staging Manual 8th Edition for Perihilar Cholangiocarcinoma

BACKGROUND

The aim was to compare the prognostic accuracy of cross-sectional imaging of the 7th and 8th editions of the American Joint Committee on Cancer(AJCC) staging system for perihilar cholangiocarcinoma(PHC).

METHODS

All patients with PHC between 2002 and 2014 were included. Imaging at the time of presentation was reassessed and clinical tumor-node-metastasis (cTNM) stage was determined according to the 7th and 8th editions of the AJCC staging system. Comparison of the prognostic accuracy was performed using the concordance index (c-index).

RESULTS

A total of 248 PHC patients were included;45 patients(18.1%) underwent a curative-intent resection, whereas 203 patients(81.9%) did not because they were unfit for surgery or were diagnosed with locally advanced or metastatic disease during workup. Prognostic accuracy was comparable between the 7th and 8th editions (c-index 0.57 vs 0.58). For patients who underwent a curative-intent resection, the prognostic accuracy of the 8th edition (0.67) was higher than the 7th (0.65). For patients who did not undergo a curative-intent resection, the prognostic accuracy was poor in both the 7th as the 8th editions (0.54 vs 0.57).

CONCLUSION

The 7th and 8th editions of the AJCC staging system for PHC have comparable prognostic accuracy. Prognostic accuracy was particularly poor in unresectable patients.

Lost in translation: confusion on resection and dissection planes hampers the interpretation of pathology reports for perihilar cholangiocarcinoma

In perihilar cholangiocarcinoma (PHC), interpretation of the resection specimen is challenging for pathologists and clinicians alike. Thorough and correct reporting is necessary for reliable interpretation of residual disease status. The aim of this study is to assess completeness of PHC pathology reports in a single center and assess what hampers interpretation of pathology reports by clinicians. Pathology reports of patients resected for PHC at a single expert tertiary center drafted between 2000 and 2018 were assessed. Reports were assessed regarding completeness, according to the guideline of the International Collaboration on Cancer Reporting (ICCR). A total of 146 reports were assessed. Prognostic tumor characteristics such as vasoinvasive growth and perineural growth were missing in 30/146 (34%) and 22/146 (15%), respectively. One or more planes were missing in 94/146 (64%) of the reports, with the periductal dissection plane missing in 51/145 (35%). Residual disease could be re-classified from R0 to R1 in 22 patients (15%). Reasons for R1 in these patients were the presence of a positive periductal dissection plane (n = 2), < 1-mm margin at the periductal dissection plane (n = 11), or liver parenchyma (n = 9). Completeness of reports improved significantly when drafted by an expert HPB pathologist. This study demonstrates that pathology reporting of PHC is challenging. Reports are frequently incomplete and often do not incorporate assessment of all resection planes and the dissection plane. The periductal dissection plane is frequently overlooked, but is a major cause of residual disease.

Low Skeletal Muscle Density Is Associated with Early Death in Patients with Perihilar Cholangiocarcinoma Regardless of Subsequent Treatment

BACKGROUND

Low skeletal muscle mass is associated with increased postoperative morbidity and worse survival following resection for perihilar cholangiocarcinoma (PHC). We investigated the predictive value of skeletal muscle mass and density for overall survival (OS) of all patients with suspected PHC, regardless of treatment.

METHODS

Baseline characteristics and parameters regarding disease and treatment were collected from all patients with PHC from 2002 to 2014. Skeletal muscle mass and density were measured at the level of the third lumbar vertebra on CT. The association between skeletal muscle mass and density with OS was investigated using the Kaplan-Meier method and Cox survival.

RESULTS

Median OS in 233 included patients did not differ between those with and without low skeletal muscle mass (p = 0.203), whereas a significantly different median OS (months) was observed between patients with low (HR 7.0, 95% CI 4.7-9.3) and high (HR 12.1, 95% CI 8.1-16.1) skeletal muscle density (p = 0.004). Low skeletal muscle density was independently associated with decreased OS (HR 1.78, 95% CI 1.03-3.07, p = 0.040) within the first 6 months but not after 6 months (HR 0.68, 95% CI 0.44-1.07, p = 0.093), after adjusting for age, tumour size and suspected peritoneal or other distant metastases on imaging.

CONCLUSION

A time-dependent effect of skeletal muscle density on OS was found in patients with PHC, regardless of subsequent treatment. Low skeletal muscle density may identify patients at risk for early death.

Preoperative Risk Score to Predict Occult Metastatic or Locally Advanced Disease in Patients with Resectable Perihilar Cholangiocarcinoma on Imaging

BACKGROUND

Many patients with resectable perihilar cholangiocarcinoma (PHC) on imaging are diagnosed intraoperatively with occult metastatic or locally advanced disease, precluding a curative-intent resection. This study aimed to develop and validate a preoperative risk score.

STUDY DESIGN

Patients with resectable PHC on imaging who underwent operations in 2 high-volume centers (US and Europe) between 2000 and 2015 were included. Multivariable logistic regression analysis was used to develop the risk score. Cross-validation was used to validate the score, alternating the 2 centers as "training" and "testing" datasets.

RESULTS

Of 566 patients who underwent operations, 309 (55%) patients had a resection, and in 257 (45%) patients, a curative-intent resection was precluded due to distant metastasis (n = 151 [27%]) or locally advanced disease (n = 106 [19%]). Preoperative predictors included bilirubin >2 mg/dL, bile duct involvement on imaging, portal vein involvement on imaging (≥180 degrees), hepatic artery involvement on imaging (≥180 degrees), and suspicious lymph nodes on imaging. The new risk score (c-index 0.75 after cross-validation) provided significantly more accurate predictions than the Bismuth classification (c-index 0.62), Blumgart T-staging (c-index 0.67), and cTNM staging (c-index 0.68). The new risk score identified 4 risk groups for occult metastatic or locally advanced disease: low (14.7%), intermediate (29.5%), high (47.3%), and very high risk (81.3%). The preoperative score groups also predicted survival after operation, irrespective of intraoperative findings (p < 0.001).

CONCLUSIONS

The validated risk score can predict occult distant metastatic or locally advanced PHC based on 5 preoperatively available factors. The score can be useful in preoperative shared decision making and selection of patients in neoadjuvant clinical trials.

The prognostic value of portal vein and hepatic artery involvement in patients with perihilar cholangiocarcinoma

BACKGROUND

Although several classifications of perihilar cholangiocarcinoma (PHC) include vascular involvement, its prognostic value has not been investigated. Our aim was to assess the prognostic value of unilateral and main/bilateral involvement of the portal vein (PV) and hepatic artery (HA) on imaging in patients with PHC.

METHODS

All patients with PHC between 2002 and 2014 were included regardless of stage or management. Vascular involvement was defined as apparent tumor contact of at least 180° to the PV or HA on imaging. Kaplan-Meier method with log-rank test was used to compare overall survival (OS) between groups. Cox regression was used for multivariable analysis.

RESULTS

In total, 674 patients were included with a median OS of 12.2 (95% CI 10.6-13.7) months. Patients with unilateral PV involvement had a median OS of 13.3 (11.0-15.7) months, compared with 14.7 (11.7-17.6) in patients without PV involvement (p = 0.12). Patients with main/bilateral PV involvement had an inferior median OS of 8.0 (5.4-10.7, p < 0.001) months. Median OS for patients with unilateral HA involvement was 10.6 (9.3-12.0) months compared with 16.9 (13.2-20.5) in patients without HA involvement (p < 0.001). Patients with main/bilateral HA involvement had an inferior median OS of 6.9 (3.3-10.5, p < 0.001). Independent poor prognostic factors included unilateral and main/bilateral HA involvement, but not PV involvement.

CONCLUSION

Both unilateral and main HA involvement are independent poor prognostic factors for OS in patients presenting with PHC, whereas PV involvement is not.

Conditional survival in patients with unresectable perihilar cholangiocarcinoma

BACKGROUND

Conditional survival is the life expectancy from a point in time for a patient who has survived a specific period after presentation. The aim of the study was to estimate conditional survival for patients with unresectable perihilar cholangiocarcinoma.

METHODS

Patients with unresectable perihilar cholangiocarcinoma from two academic hospitals in the Netherlands between 2002 and 2012 were assessed. A multivariable Cox proportional hazards analysis was performed to identify risk factors associated with overall survival. Survival was estimated using the Kaplan-Meier method to evaluate factors associated with overall survival.

RESULTS

In total, 572 patients were included. Overall survival was 42% at one year and 6% at three years. The conditional chance of surviving three years was 15% at 1 year and increased to 38% at 2 years. Independent poor prognostic factors for overall survival were age ≥65 years, tumor size >3 cm on imaging, bilirubin levels (>250 μmol/L), CA19-9 level at presentation (>1000 U/ml), and suspected distant metastases on imaging. The conditional survival of patients with and without these prognostic factors was comparable after patients survived the first two or more years.

CONCLUSION

The conditional chance of surviving for patients with unresectable perihilar cholangiocarcinoma increases with time. Poor prognostic factors become less relevant once patients have survived two years.