The Limitations of Standard Clinicopathologic Features to Accurately Risk-Stratify Prognosis after Resection of Intrahepatic Cholangiocarcinoma

Mechanism of postoperative recurrence and metastasis of intrahepatic cholangiocellular carcinoma and clinical prevention and treatment strategy

Intrahepatic cholangiocellular carcinoma is a primary adenocarcinoma originating from intrahepatic bile duct epithelial cells. The tumor has no capsule. At the early stage of the tumor, there are infiltration and metastasis along the lymphatic vessels, blood vessels, perineural space, and loose fibrous connective tissue, which are characterized by lymph node metastasis. Due to the absence of characteristic clinical manifestations and the lack of specific molecular markers for early diagnosis, the surgical resection rate is low and the postoperative tumor recurrence and metastasis rate is high. Low efficacy of chemoradiotherapy, molecular targeted drugs, and immunotherapy results in the poor prognosis. Further research of molecular pathology, gene function, and imaging technology can help elucidate the occurrence, recurrence, and metastasis mechanism of intrahepatic cholangiocellular carcinoma to improve its early diagnosis rate and precise clinical staging. Individualized precision treatment and prevention for the risk factors to reduce the recurrence and metastasis rate postoperatively are key to improving the patient prognosis.

Call to Improve the Quality of Prediction Tools for Intrahepatic Cholangiocarcinoma Resection: A Critical Appraisal, Systematic Review, and External Validation Study

Objective

To conduct a systematic review, critical appraisal, and external validation of survival prediction tools for patients undergoing intrahepatic cholangiocarcinoma (iCCA) resection.

Summary background data

Despite the development of several survival prediction tools in recent years for patients undergoing iCCA resections, there is a lack of critical appraisal and external validation of these models.

Methods

We conducted a systematic review and critical appraisal of survival and recurrence prediction models for patients undergoing curative-intent iCCA resections. Studies were evaluated based on their model design, risk of bias, reporting, performance, and validation results. We identified the best model and externally validated it using our institution's data.

Results

This review included a total of 31 studies, consisting of 26 studies with original prediction tools and 5 studies that only conducted external validations. Among the 26, 54% of the studies conducted internal validations, 46% conducted external validations, and only 1 study scored a low risk of bias. Harrell's C-statistics ranged from 0.67 to 0.76 for internal validation and from 0.64 to 0.75 for external validation. Only 81% of the studies reported model calibration. Our external validation of the best model (Intrahepatic Cholangiocarcinoma [ICC]-Metroticket) estimated Harrell's and Uno's C-statistics of 0.67 (95% CI: 0.56-0.77) and Uno's time-dependent area under the receiver operating characteristic curve (AUC) of 0.71 (95% CI: 0.53-0.88), with a Brier score of 0.20 (95% CI: 0.15-0.26) and good calibration plots.

Conclusions

Many prediction models have been published in recent years, but their quality remains poor, and minimal methodological quality improvement has been observed. The ICC-Metroticket was selected as the best model (Uno's time-dependent AUC of 0.71) for 5-year overall survival prediction in patients undergoing curative-intent iCCA resection.

Prognostic analysis of patients with combined hepatocellular-cholangiocarcinoma after radical resection: A retrospective multicenter cohort study

BACKGROUND

Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a form of rare primary liver cancer that combines intrahepatic cholangiocarcinoma (ICC) and hepatocellular carcinoma.

AIM

To investigate overall survival (OS) and recurrence-free survival (RFS) after radical resection in patients with cHCC-CCA, and the clinicopathological factors affecting prognosis in two center hospitals of China.

METHODS

We reviewed consecutive patients with cHCC-CCA who received radical resection between January 2005 and September 2021 at Peking Union Medical College and the 5th Medical Center of the PLA General Hospital retrospectively. Regular follow-up and clinicopathological characteristics were systematic collected for baseline and prognostic analysis.

RESULTS

Our study included 95 patients who received radical resection. The majority of these patients were male and 82.7% of these patients were infected with HBV. The mean tumor size was 4.5 cm, and approximately 40% of patients had more than one lesion. The median OS was 26.8 (95%CI: 18.5-43.0) mo, and the median RFS was 7.27 (95%CI: 5.83-10.3) mo. Independent predictors of OS were CA19-9 ≥ 37 U/mL (HR = 8.68, P = 0.002), Child-Pugh score > 5 (HR = 5.52, P = 0.027), tumor number > 1 (HR = 30.85, P = 0.002), tumor size and transarterial chemoembolization (TACE) after surgery (HR = 0.2, P = 0.005).

CONCLUSION

The overall postoperative survival of cHCC-CCA patients is poor, and most patients experience relapse within a short period of time after surgery. Preoperative tumor biomarker (CA19-9, alpha-fetoprotein) levels, tumor size, and Child-Pugh score can significantly affect OS. Adjuvant TACE after surgery prolongs RFS, suggesting that TACE is a possible option for postoperative adjuvant therapy in patients with cHCC-CCA.

A combined Cox and logistic model provides accurate predictive performance in estimation of time-dependent probabilities for recurrence of intrahepatic cholangiocarcinoma after resection

Background

Intrahepatic cholangiocarcinoma has heterogeneous outcomes after resection. There remains a need for broadly applicable recurrence-specific tool offering precise evaluation on curativeness of resection.

Methods

A four hospital-based clinical cohort involving 1,655 patients with intrahepatic cholangiocarcinoma who received surgical resection were studied. Cox and logistic models were networked into one system containing risk categories with distinctive probabilities of recurrence. Prediction of time-to-recurrence was performed by formulizing time-dependent risk probabilities. The model was validated in three clinical cohorts (n=332).

Results

From the training cohort, 10 and 11 covariates, including diabetes, cholelithiasis, albumin, platelet count, alpha fetoprotein, carbohydrate antigen 19-9, carcinoembryonic antigen, hepatitis B virus infection, tumor size and number, resection type, and lymph node metastasis, from Cox and logistic models were identified significant for recurrence-free survival (RFS). The combined Cox & logistic ranking system (CCLRS)-adjusted time-dependent probabilities were categorized into seven ranks (5-yr RFS for lowest and highest ranks were 75% vs. 0%; hazard ratio 18.5, 95% CI: 14.7-24.9, P<0.0001). The CCLRS was validated with a minimum area under curve value of 0.8086. Prediction of time-to-recurrence was validated to be excellent (Pearson r, 0.8204; P<0.0001).

Conclusions

The CCLRS allows precise estimation on risk of recurrence for intrahepatic cholangiocarcinoma after resection. It could be applicative when estimating time-dependent disease status and stratifying individuals who sole resection of the tumor would not be curative.

Compelling Long-Term Results for Liver Resection in Early Cholangiocarcinoma

Surgery for intrahepatic cholangiocarcinoma (iCCA) is associated with a high rate of recurrence even after complete resection. To achieve acceptable results, preoperative patient selection is crucial. Hence, we aimed to identify preoperative characteristics with prognostic value focusing on certain radiological features. Patients who underwent hepatectomy for iCCA between 2010 and 2020 at University Hospital, RWTH Aachen were included. Kaplan–Meier and Cox regressions were applied for survival analysis and associations of overall survival (OS) and recurrence-free survival (RFS) with clinical/radiological characteristics, respectively. Based on radiological features patients were stratified into three groups: single nodule ≤ 3 cm, single nodule > 3 cm, and ≥2 nodules. Analysis of 139 patients revealed a mean OS of 142 months for those with a single nodule ≤3 cm, median OS of 28 months with a single nodule >3 cm, and 19 months with ≥2 nodules, respectively. Multivariable analyses based on preoperative characteristics showed the radiological stratification to be independently associated with OS (HR (hazard ratio) = 4.25 (1 nodule, >3 cm), HR = 5.97 (≥2 nodules), p = 0.011), RFS (HR = 4.18 (1 nodule, >3 cm), and HR = 11.07 (≥2 nodules), p = 0.001). In conclusion, patients with single iCCA ≤3 cm show compelling OS and RFS. Basic radiological features (e.g., nodule size, number) are prognostic for patients undergoing surgery and useful in preoperative patient selection.

Artificial neural networks for multi-omics classifications of hepato-pancreato-biliary cancers: towards the clinical application of genetic data

PURPOSE

Several multi-omics classifications have been proposed for hepato-pancreato-biliary (HPB) cancers, but these classifications have not proven their role in the clinical practice and been validated in external cohorts.

PATIENTS AND METHODS

Data from whole-exome sequencing (WES) of The Cancer Genome Atlas (TCGA) patients were used as an input for the artificial neural network (ANN) to predict the anatomical site, iClusters (cell-of-origin patterns) and molecular subtype classifications. The Ohio State University (OSU) and the International Cancer Genome Consortium (ICGC) patients with HPB cancer were included in external validation cohorts. TCGA, OSU and ICGC data were merged, and survival analyses were performed using both the 'classic' survival analysis and a machine learning algorithm (random survival forest).

RESULTS

Although the ANN predicting the anatomical site of the tumour (i.e. cholangiocarcinoma, hepatocellular carcinoma of the liver, pancreatic ductal adenocarcinoma) demonstrated a low accuracy in TCGA test cohort, the ANNs predicting the iClusters (cell-of-origin patterns) and molecular subtype classifications demonstrated a good accuracy of 75% and 82% in TCGA test cohort, respectively. The random survival forest analysis and Cox' multivariable survival models demonstrated that models for HPB cancers that integrated clinical data with molecular classifications (iClusters, molecular subtypes) had an increased prognostic accuracy compared with standard staging systems.

CONCLUSION

The analyses of genetic status (i.e. WES, gene panels) of patients with HPB cancers might predict the classifications proposed by TCGA project and help to select patients suitable to targeted therapies. The molecular classifications of HPB cancers when integrated with clinical information could improve the ability to predict the prognosis of patients with HPB cancer.

Evaluation and Recommendation of the 8th Edition of American Joint Committee on Cancer (AJCC) Staging System for Intrahepatic Cholangiocarcinoma (ICC) in 820 Patients from the Surveillance, Epidemiology, and End Results (SEER) Database

BACKGROUND

The AJCC made four changes to T category in the 8th AJCC stage for ICC, but this is a topic of debate.

METHODS

Data from 820 patients with ICC were extracted from the SEER database. Survival analysis of the 8th AJCC stage was examined.

RESULTS

To verify the four T staging changes by survival analysis: prognosis of patients with tumor size > 5 cm was poorer than that with tumor size ≤ 5 cm (P < 0.05); in N0M0 cohort, there was no significant difference in survival between solitary tumor with vascular invasion and multiple tumors (P = 0.092), tumor perforating the visceral peritoneum with and without involving local extrahepatic structures by direct invasion (P = 0.470), and tumor with and without periductal invasion (PI) (P = 0.220). The prognosis of patients with ≥ 4 positive lymph nodes was relatively poor compared with 1-3 positive lymph nodes (P = 0.037) and similar to patients with stage IV (8th AJCC, P = 0.585).

CONCLUSION

This study found that there was no significant difference in survival between tumor perforating the visceral peritoneum with and without involving local extrahepatic structures by direct invasion, whereas other T staging changes were effective. The inclusion of the number of positive lymph nodes in the 8th AJCC stage may improve prognostic discrimination in ICC patients.

Trends in centralization of surgical care and compliance with National Cancer Center Network guidelines for resected cholangiocarcinoma

BACKGROUND

A retrospective study was performed to characterize trends in centralization of care and compliance with National Comprehensive Cancer Network (NCCN) guidelines for resected cholangiocarcinoma (CCA), and their impact on overall survival (OS).

METHODS

Using the National Cancer Database (NCDB) 2004-2015 we identified patients undergoing resection for CCA. Receiver Operating Characteristic (ROC) analyses identified time periods and hospital volume groups for comparison. Propensity score matching provided case-mix adjusted patient cohorts. Cox hazard analysis identified risk factors for OS.

RESULTS

Among the 40,338 patients undergoing resection for CCA, the proportion of patients undergoing surgery at high volume hospitals increased over time (25%-44%, p < 0.001), while the proportion of patients undergoing surgery at low volume hospitals decreased (30%-15%, p < 0.001). Using ROC analyses, a hospital volume of 14 operations/year was the most sensitive and specific value associated with mortality. Surgery at high volume hospitals [HR] = 0.92, 95% CI: 0.88-0.97, p < 0.001) and receipt of care compliant with NCCN guidelines (HR = 0.87, 95% CI: 0.83-0.91, p < 0.001) were independently associated with improved OS.

CONCLUSIONS

Both centralization of surgery for CCA to high volume hospitals and increased compliance with NCCN guidelines were associated with significant improvements in overall survival.

Intrahepatic cholangiocarcinoma tumor burden: A classification and regression tree model to define prognostic groups after resection

BACKGROUND

Tumor burden is an important factor in defining prognosis among patients with primary and secondary liver cancers. Although the eighth edition of the American Joint Committee on Cancer staging system has changed the criteria for staging patients with intrahepatic cholangiocarcinoma to better define the effect of tumor burden on prognosis, the impact of intrahepatic cholangiocarcinoma tumor burden on overall survival has not been examined using a machine-learning tool.

METHODS

Patients who underwent resection of intrahepatic cholangiocarcinoma at 1 of 14 participating international hospitals between 1990 and 2015 were identified. Classical survival models and the Classification and Regression Tree model were used to identify groups of patients with a homogeneous risk of death and investigate the hierarchical association between variables and overall survival.

RESULTS

Among 1,116 patients included in the analysis, tumor size was ≤5 cm in 447 (40.1%) patients and >5 cm in 669 (59.9%) patients. Although 82.9% (n = 926) of patients had a single intrahepatic cholangiocarcinoma, 9.9% (n = 110) and 7.2% (n = 80) of patients had 2 and ≥3 tumors, respectively. Patients with intrahepatic cholangiocarcinoma tumors ≤5 cm and >5 cm had a 5-year overall survival of 51.7% and 32.6%, respectively (P < 0.001). Five-year overall survival decreased from 44.6% among patients with a single intrahepatic cholangiocarcinoma to 28.1% and 14.2% among patients with 2 and ≥3 intrahepatic cholangiocarcinomas, respectively (P < 0.001). Among the combinations of tumor size and intrahepatic cholangiocarcinoma tumor number used to estimate tumor burden, logarithmic transformation of tumor size (log tumor size) and intrahepatic cholangiocarcinoma tumor number had the highest concordance index. The Classification and Regression Tree model identified 8 classes of patients with a homogeneous risk of death, illustrating the hierarchical relationship between tumor burden (log tumor size and number of intrahepatic cholangiocarcinomas) and other factors associated with prognosis.

CONCLUSION

Intrahepatic cholangiocarcinoma tumor size and number demonstrated a strong nonlinear association with survival after resection of intrahepatic cholangiocarcinoma. A log-model Classification and Regression Tree-derived tumor burden score may be a better tool to estimate prognosis of patients undergoing curative-intent resection of intrahepatic cholangiocarcinoma.

Anatomical, histomorphological and molecular classification of cholangiocarcinoma

Cholangiocarcinoma constitutes a heterogeneous group of malignancies that can emerge at any point of the biliary tree. Cholangiocarcinoma is classified into intrahepatic, perihilar and distal based on its anatomical location. Histologically, conventional perihilar/distal cholangiocarcinomas are mucin-producing adenocarcinomas or papillary tumours; intrahepatic cholangiocarcinomas are more heterogeneous and can be sub-classified according to the level or size of the displayed bile duct. Cholangiocarcinoma develops through multistep carcinogenesis and is preceded by dysplastic and in situ lesions. Definition and clinical significance of precursor lesions, including biliary intraepithelial neoplasia, intraductal papillary neoplasms of the bile duct, intraductal tubulopapillary neoplasms and mucinous cystic neoplasm, are discussed in this review. A main challenge in diagnosing cholangiocarcinoma is the fact that tumour tissue for histological examination is difficult to obtain. Thus, a major clinical obstacle is the establishment of the correct diagnosis at a tumour stage that is amenable to surgery which still represents the only curable therapeutic option. Current standards, methodology and criteria for diagnosis are discussed. Cholangiocarcinoma represents a heterogeneous tumour with regard to molecular alterations. In intrahepatic subtype, mainly two distinctive morpho-molecular groups can currently be discriminated. Large-duct type intrahepatic cholangiocarcinoma shows a high mutation frequency of oncogenes and tumour suppressor genes, such as KRAS and TP53 while Isocitrate Dehydrogenase 1/2 mutations and Fibroblast Growth Factor Receptor 2-fusions are typically seen in small-duct type tumours. It is most important to ensure the separation of the given anatomical subtypes and to search for distinct subgroups within the subtypes on a molecular and morphological basis.

A novel online prognostic tool to predict long-term survival after liver resection for intrahepatic cholangiocarcinoma: The "metro-ticket" paradigm

BACKGROUND

The aim of the current study was to develop an online calculator to predict survival after liver resection for intrahepatic cholangiocarcinoma (ICC) based on the "metro-ticket" paradigm.

METHODS

Between 1990 and 2016, patients who underwent liver resection for ICC were identified in an international multi-institutional database. The final multivariable model of survival was used to develop an online prognostic calculator of survival.

RESULTS

Among 643 patients, actual 5-year overall survival (OS) after resection for ICC was 42.7%. On multivariable analysis, CA19-9 > 200 (hazard ratio (HR), 2.62; 95% CI, 2.01-3.42), sum of the number and largest tumor size >7 (HR, 1.88; 95% CI, 1.46-2.42), N1 disease (HR, 2.87; 95% CI, 1.98-4.16), R1 resection (HR, 1.72; 95% CI, 1.21-2.46), poor/undifferentiated tumor grade (HR, 1.74; 95% CI, 1.25-2.44), major vascular invasion (HR, 1.47; 95% CI, 1.03-2.10), and adjuvant chemotherapy (HR, 0.64; 95% CI, 0.45-0.89) were significantly associated with survival and were included in the online calculator. The predictive accuracy of the model was good to very good as the C-statistics to predict 5-year OS was 0.696 in the training dataset and 0.672 with bootstrapping resamples (n = 5000) in the test dataset.

CONCLUSION

A novel, online calculator was developed to estimate the 5-year survival probability for patients undergoing resection for ICC. This tool could help provide useful information to guide treatment decision-making and inform conversations about prognosis.

Impact of body mass index on tumor recurrence among patients undergoing curative-intent resection of intrahepatic cholangiocarcinoma- a multi-institutional international analysis

BACKGROUND

The association between body mass index (BMI) and long-term outcomes of patients with ICC has not been well defined. We sought to define the presentation and oncologic outcomes of patients with ICC undergoing curative-intent resection, according to their BMI category.

METHODS

Patients who underwent resection of ICC were identified in a multi-institutional database. Patients were categorized as normal weight (BMI 18.5-24.9 kg/m²), overweight (BMI 25.0-29.9 kg/m²) and obese (BMI≥30 kg/m²) according to the World Health Organization (WHO) definition. Impact of clinico-pathological factors on recurrence-free survival (RFS) was assessed using Cox proportional hazards model among patients in the three BMI categories.

RESULTS

Among a total of 790 patients undergoing curative-intent resection of ICC in the analytic cohort, 399 (50.5%) had normal weight, 274 (34.7%) were overweight and 117 (14.8%) were obese. Caucasian patients were more likely to be obese (66.7%, n = 78) and overweight (47.1%, n = 129) compared with Asian (obese: 18.8%, n = 22; overweight: 46%, n = 126) and other races (obese: 14.5%, n = 17; overweight: 6.9%, n = 19)(p < 0.001). There were no differences in the presence of cirrhosis (10.9%, vs. 12.8%, vs. 12.9%), preoperative jaundice (8.6% vs. 9.5% vs. 12.0%), or levels of CA 19-9 (75, IQR 24.6-280 vs. 50.9, IQR 17.9-232 vs. 43, IQR 16.9-192.7) among the BMI groups (all p > 0.05). On multivariable analysis, increased BMI was an independent risk factor for tumor recurrence (OR 1.16, 95% CI 1.02-1.32, for every 5 unit increase).

CONCLUSION

Increasing BMI was associated with incremental increases in the risk of recurrence following curative-intent resection of ICC. Future studies should aim to achieve a better understanding of BMI-related factors relative to prognosis of patients with ICC.

Surgical resection of lymph node positive intrahepatic cholangiocarcinoma may not improve survival

BACKGROUND

Nodal positivity is a predictor of poor survival following resection for intrahepatic cholangiocarcinoma (ICC). The aim of this study was to evaluate the impact of surgical resection on survival in patients with lymph node (LN) positive ICC.

METHODS

An augmented version of the Surveillance, Epidemiology, and End Results program database was utilized to identify patients with LN-positive ICC without distant metastases from 2000 to 2014. Patients were stratified by treatment: chemotherapy alone or surgical resection with/without chemotherapy. Survival was evaluated using Kaplan-Meier and Cox proportional hazard models.

RESULTS

169 patients who underwent treatment for LN-positive ICC were identified. 88% underwent surgical resection and 12% underwent chemotherapy alone. The median survival for patients who underwent surgical resection was not different from patients treated with chemotherapy alone (19 months 95% Confidence Interval (CI) 17-33 versus 20 months CI 10-27, p = 0.323). A cox-proportional hazard ratio model demonstrated that black race was associated with worse survival (p < 0.05), while surgical resection was not independently associated with survival.

CONCLUSION

Surgical resection for patients with LN-positive ICC may not improve survival compared to chemotherapy alone. Pathologic LN evaluation should be performed prior to surgical resection, to improve patient selection and ensure receipt of optimal therapy.