Radiofrequency Ablation vs. Surgical Resection for Small Early-Stage Primary Intrahepatic Cholangiocarcinoma

Radiofrequency ablation with sine and square electrical waveforms to enhance ablation range

Radiofrequency ablation (RFA) is a local treatment modality for primary liver cancers. Although various input parameters of the RF generator have been adjusted to improve the ablation ranges, the limited ablation ranges remain an obstacle to RFA. This study aimed to compare the ablation ranges and efficacy of sine and square electrical waveforms in a mouse tumor model. An RF generator with an adjustable electrical waveform was developed, and its ablation range in the porcine liver was compared. For all RF parameters, the square electrical waveform ablation range was greater than that of the sine electrical waveform (all p < 0.001) in the porcine liver. The 45 BALB/c nude mice were used to evaluate the efficacy of the two electrical waveforms after the RFA. The mean tumor volume in the square group was significantly lower than that in the sine group (p < 0.001), indicating a higher survival rate (60%). The cellular coagulative necrosis, inflammatory cell infiltration, heat shock proteins, cellular necrosis, and tumor necrosis were significantly greater in square electrical waveform than in sine electrical waveform (all; p < 0.05). RFA with square electrical waveforms has therapeutic potential for tumor management with an enhanced ablation range.

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.

Tumor size and survival in intrahepatic cholangiocarcinoma treated with surgical resection or ablation

OBJECTIVES

We performed a retrospective analysis within a national cancer registry on outcomes following resection or ablation for intrahepatic cholangiocarcinoma (iCCA).

METHODS

The National Cancer Database was queried for patients with clinical stage I-III iCCA diagnosed during 2010-2018, who underwent resection or ablation. Overall survival (OS) was compared with Kaplan-Meier and multivariable Cox proportional hazards methods.

RESULTS

Of 2140 patients, 1877 (87.7%) underwent resection and 263 (12.3%) underwent ablation, with median tumor sizes of 5.5 and 3 cm, respectively. Overall, resection was associated with greater median OS (41.2 months (95% confidence interval [95% CI]: 37.6-46.2) vs. 28 months (95% CI: 15.9-28.6) on univariable analysis (p < 0.0001). There was no significant difference on multivariable analysis (p = 0.42); however, there was a significant interaction between tumor size and management. On subgroup analysis of patients with tumors <3 cm, there was no difference in OS between resection versus ablation. However, ablation was associated with increased mortality for tumors ≥3 cm.

CONCLUSION

Although resection is associated with improved OS for tumors ≥3 cm, we observed no difference in survival between management strategies for tumors < 3 cm. Ablation may be an alternative therapeutic strategy for small iCCA, particularly in patients at risk for high surgical morbidity.

Extracellular volume fraction using contrast-enhanced CT is useful in differentiating intrahepatic cholangiocellular carcinoma from hepatocellular carcinoma

Objectives

To evaluate whether tumor extracellular volume fraction (fECV) on contrast-enhanced computed tomography (CT) aids in the differentiation between intrahepatic cholangiocarcinoma (ICC) and hepatocellular carcinoma (HCC).

Methods

In this retrospective study, 113 patients with pathologically confirmed ICC (n = 39) or HCC (n = 74) who had undergone preoperative contrast-enhanced CT were enrolled. Enhancement values of the tumor (Etumor) and aorta (Eaorta) were obtained in the precontrast and equilibrium phase CT images. fECV was calculated using the following equation: fECV [%] = Etumor/Eaorta × (100 - hematocrit [%]). fECV values were compared between the ICC and HCC groups using Welch's t-test. The diagnostic performance of fECV for differentiating ICC and HCC was assessed using receiver-operating characteristic (ROC) analysis. fECV and the CT imaging features of tumors were evaluated by two radiologists. Multivariate logistic regression analysis was performed to identify factors predicting a diagnosis of ICC.

Results

Mean fECV was significantly higher in ICCs (43.8% ± 13.2%) than that in HCCs (31.6% ± 9.0%, p < 0.001). The area under the curve for differentiating ICC from HCC was 0.763 when the cutoff value of fECV was 41.5%. The multivariate analysis identified fECV (unit OR: 1.10; 95% CI: 1.01-1.21; p < 0.05), peripheral rim enhancement during the arterial phase (OR: 17.0; 95% CI: 1.29-225; p < 0.05), and absence of washout pattern (OR: 235; 95% CI: 14.03-3933; p < 0.001) as independent CT features for differentiating between the two tumor types.

Conclusions

A high value of fECV, peripheral rim enhancement during the arterial phase, and absence of washout pattern were independent factors in the differentiation of ICC from HCC.

Role of Percutaneous Ablation in the Management of Intrahepatic Cholangiocarcinoma

Cholangiocarcinoma (CCA) is an invasive cancer accounting for <1% of all cancers and 10-15% of primary liver cancers. Intrahepatic CCA (iCCA) is associated with poor survival rates and high post-surgical recurrence rates whilst most diagnosed patients are not surgical candidates. There is a growing literature suggesting percutaneous ablative techniques for the management of patients with iCCA measuring ≤3 cm with contraindications to surgery as well as for recurrent or residual tumors aiming to provide local cancer treatment and control. Most used ablative therapies for iCCA include radiofrequency and microwave ablation with irreversible electroporation, cryoablation and reversible electroporation (electrochemotherapy) being less commonly encountered techniques. Due to the infiltrative margins of the lesion, there is a need for larger safety margins and ablation zone; multi-apparatus ablation or other variations of the technique such as balloon-assisted approaches can be utilized aiming to increase size of the zone of necrosis. The present review paper focuses upon the current role of percutaneous ablative techniques for the therapeutic management of iCCA. The purpose of this review is to present the current minimally invasive ablative techniques in the treatment of iCCA, including local control and survival rates.

Locoregional Therapy for Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) has a poor prognosis, and surgical resection (SR) offers the only potential for cure. Unfortunately, only a small proportion of patients are eligible for resection due to locally advanced or metastatic disease. Locoregional therapies (LRT) are often used in unresectable liver-only or liver-dominant ICC. This review explores the role of these therapies in the treatment of ICC, including radiofrequency ablation (RFA), microwave ablation (MWA), transarterial chemoembolization (TACE), transarterial radioembolization (TARE), external beam radiotherapy (EBRT), stereotactic body radiotherapy (SBRT), hepatic arterial infusion (HAI) of chemotherapy, irreversible electroporation (IE), and brachytherapy. A search of the current literature was performed to examine types of LRT currently used in the treatment of ICC. We examined patient selection, technique, and outcomes of each type. Overall, LRTs are well-tolerated in the treatment of ICC and are effective in improving overall survival (OS) in this patient population. Further studies are needed to reduce bias from heterogenous patient populations and small sample sizes, as well as to determine whether certain LRTs are superior to others and to examine optimal treatment selection.

Disparities in curative treatments and outcomes for early stage intrahepatic cholangiocarcinoma in the United States

BACKGROUND

Curative surgical treatments afford the best prognosis for patients with intrahepatic cholangiocarcinoma (iCCA); however, the comparative effectiveness of treatment options and factors associated with curative treatment receipt for early stage iCCA remain unknown.

METHODS

The authors identified patients who were diagnosed with early stage iCCA, defined as a unifocal tumor <3 cm, during 2004-2018 from the National Cancer Database. Multivariable logistic and Cox regression analyses were used to identify the factors associated with curative treatment and overall survival (OS), respectively.

RESULTS

The proportion of patients with early stage iCCA increased from 4.5% in 2004 to 7.3% in 2018, with the odds of early stage detection increasing by 3.1% per year (odds ratio [OR], 1.031; 95% CI, 1.015-1.049). Of 1093 patients who had early stage iCCA, 464 (42.5%) underwent resection, 113 (10.3%) underwent ablation, 62 (5.7%) underwent liver transplantation, and 454 (41.5%) received noncurative treatments. Hispanic patients (adjusted OR [aOR], 0.57; 95% CI, 0.33-0.97) and Black patients (aOR, 0.47; 95% CI, 0.28-0.77) were less likely to receive curative treatments than White patients. Compared with patients who underwent surgical resection, those who underwent liver transplantation had a trend toward improved OS (adjusted hazard ratio [aHR], 0.63; 95% CI, 0.37-1.08), whereas those who underwent local ablation (aHR, 1.39; 95% CI, 1.01-1.92) and noncurative treatments (aHR, 3.97; 95% CI, 3.24-4.88) experienced worse OS.

CONCLUSIONS

More than one third of patients with early stage iCCA did not receive curative treatment, with Hispanic and Black patients being less likely to receive curative treatments than White patients. Surgical resection and liver transplantation were associated with improved survival compared with local ablation. Future studies should investigate disparities in curative treatment receipt and outcomes for early stage iCCA.

Bioinformatics Analysis of Inflammation Gene Signature in Indicating Cholangiocarcinoma Prognosis

Aim. We studied inflammatory response-related genes in cholangiocarcinoma by bioinformatics analysis. Methods. The expression profiles and clinical information of cholangiocarcinoma patients were downloaded from the TCGA cohort and the Gene Expression Omnibus. The greatest absolute shrinking and selecting operator Cox analyses were utilized to build a multigene predictive signature. Results. An inflammation response-related gene profile was generated using LASSO-Cox regression analysis of Homo sapiens bestrophin 1 (BEST1), Chemokine (C–C motif) ligand 2 (CCL2), and plasminogen activator, urokinase receptor (PLAUR). Individuals in the highest category had a significantly lower overall survival time than those from the low-risk group. A receiver operating curve analysis was used to demonstrate the predictive ability of the predictive gene signature. Through multivariate Cox analysis, the risk score was discovered to be a predictor of overall survival (OS). According to functional assessments, the immunological state and milieu of the two risk areas were significantly different. The expression levels of predictive genes were found to be strongly linked to the sensitivity of cancer cells to antitumor therapy. Conclusion. A new signature made up of three respective response-relevant genes is found to be a promising indicator of prognosis by influencing the immune condition and tumor microenvironment.

Yttrium-90 Radioembolization of Unresectable Intrahepatic Cholangiocarcinoma: Long-Term Follow-up for a 136-Patient Cohort

PURPOSE

Unresectable intrahepatic cholangiocarcinoma (ICC) signifies a poor prognosis with limited treatment options beyond systemic chemotherapy. This study's purpose was to evaluate the safety, efficacy, and potential for downstaging to resection of yttrium-90 (Y90) radioembolization for treatment of unresectable ICC.

MATERIALS AND METHODS

From 2004 to 2020, 136 patients with unresectable ICC were treated with radioembolization at a single institution. Retrospective review was performed of a prospectively collected database. Outcomes were (1) biochemical and clinical toxicities, (2) local tumor response, (3) time to progression, and (4) overall survival (OS) after Y90. Univariate/multivariate survival analyses were performed. A subgroup analysis was performed to calculate post-resection recurrence and OS in patients downstaged to resection after Y90.

RESULTS

Grade 3+ clinical and biochemical toxicities were 7.6% (n = 10) and 4.9% (n = 6), respectively. Best index lesion response was complete response in 2 (1.5%), partial response in 42 (32.1%), stable disease in 82 (62.6%), and progressive disease in 5 (3.8%) patients. Median OS was 14.2 months. Solitary tumor (P < 0.001), absence of vascular involvement (P = 0.009), and higher serum albumin (P < 0.001) were independently associated with improved OS. Eleven patients (8.1%) were downstaged to resection and 2 patients (1.5%) were bridged to transplant. R0-resection was achieved in 8/11 (72.7%). Post-resection median recurrence and OS were 26.3 months and 39.9 months, respectively.

CONCLUSION

Y90 has an acceptable safety profile and high local disease control rates for the treatment of unresectable ICC. Downstaging to resection with > 3 years survival supports the therapeutic role of Y90 for unresectable ICC.

LEVEL OF EVIDENCE

Level 3, single-arm single-center cohort study.

A blood-based noninvasive miRNA signature for predicting survival outcomes in patients with intrahepatic cholangiocarcinoma

BACKGROUND

The prognosis in patients with intrahepatic cholangiocarcinoma (ICC) is generally poor. To improve treatment selection, we sought to identify microRNA (miRNA) signature associated with survival outcomes in ICC.

METHODS

We first analysed the miRNA expression profiles of primary ICC from two public datasets to identify a miRNA panel to detect patients for short-term survival. We then analysed 309 specimens, including 241 FFPE samples from two clinical cohorts (training: n = 177; validation: n = 64) and matched plasma samples (n = 68), and developed a risk-stratification model incorporating the panel and CA 19-9 levels to predict survival outcomes in ICC.

RESULTS

We identified a 7-miRNA panel that robustly classified patients with poor outcomes in the discovery cohorts (AUC = 0.80 and 0.88, respectively). We subsequently trained this miRNA panel in a clinical cohort (AUC = 0.83) and evaluated its performance in an independent validation cohort (AUC = 0.82) and plasma samples from the additional validation cohort (AUC = 0.78). Patients in both clinical cohorts who were classified as high-risk had significantly worse prognosis (p < 0.01). The risk-stratification model demonstrated superior performance compared to models (AUC = 0.85).

CONCLUSIONS

We established a novel miRNA signature that could robustly predict survival outcomes in resected tissues and liquid biopsies to improve the clinical management of patients with ICC.

Liver Transplantation for Intrahepatic Cholangiocarcinoma: Ready for Prime Time?

Cholangiocarcinoma (CCA) represents the second-most common primary liver malignancy after HCC and has risen in incidence globally in the past decades. Intrahepatic cholangiocarcinoma (iCCA) comprises 20% of all CCAs, with the rest being extrahepatic (including perihilar [pCCA] and distal CCA). Though long representing an absolute contraindication for liver transplantation (LT), recent analyses of outcomes of LT for iCCA have suggested that iCCA may be a potentially feasible option for highly selected patients. This has been motivated both by successes noted in outcomes of LT for other malignancies, such as HCC and pCCA, and by several retrospective reviews demonstrating favorable results with LT for a selected group of iCCA patients with small lesions. LT for iCCA is primarily relevant within two clinical scenarios. The first includes patients with very early disease (single tumor, ≤2 cm) with cirrhosis and are not candidates for liver resection (LR). The second scenario is patients with locally advanced iCCA, but where the extent of LR would be too extensive to be feasible. Preliminary single-center reports have described LT in a selected group of patients with locally advanced tumors who have responded to neoadjuvant therapy and have a period of disease stability. Currently, there are three prospective trials underway that will help clarify the role of LT in iCCA. This review seeks to explore the available studies involving LT for iCCA, the challenges of ongoing trials, and opportunities for the future.

Image-Guided Local Treatment for Unresectable Intrahepatic Cholangiocarcinoma-Role of Interventional Radiology

Intrahepatic cholangiocarcinoma is a highly aggressive malignancy with an increasing incidence in recent years. Prognosis is poor and most patients are not eligible for resection at the time of initial diagnosis due to the anatomic location, inadequate hepatic reserve, limiting comorbidities or metastatic disease. Several locoregional therapies from the field of interventional radiology exist for patients who are not amenable for surgery, or in case of local recurrence as a single treatment modality or combined with systemic treatment. To date, evidence is limited, with most conclusions drawn from single-center studies with small patient cohorts, often treated in the salvage situation or for local recurrence after initial resection. Nevertheless, the results are promising and suggest a survival benefit in selected patients. This narrative review focuses on the use of different locoregional treatment options for intrahepatic cholangiocarcinoma.

Thermal ablation in the treatment of intrahepatic cholangiocarcinoma: a systematic review and meta-analysis

OBJECTIVE

To summarize the efficacy and safety of thermal ablation for the treatment of intrahepatic cholangiocarcinoma (ICC).

METHODS

MEDLINE, EMBASE, Cochran Library, and Web of Science databases were searched for studies reporting outcomes in patients with ICC treated with thermal ablation. Meta-analyses of cumulative overall survival (OS) and recurrence-free survival (RFS), Kaplan-Meier survival rates according to time to local tumor progression (TTLTP), technical efficacy, and incidence of complications were analyzed. Pooled hazard ratios of common variables were calculated to explore factors associated with OS.

RESULTS

Twenty observational studies comprising 917 patients were reviewed (primary ICC [n = 502]; post-surgical recurrent ICC [n = 355]; information not available [n = 60]). The pooled proportion of technical efficacy was 91.9% (95% CI, 87.3-94.9%). The pooled 1-, 3-, and 5-year OS rates were 82.4% (95% CI, 75.1-88.9%), 42.1% (95% CI, 36.0-48.4%), and 28.5% (95% CI, 21.2-36.2%). Primary tumors showed higher 3-year OS rates than recurrent ones, with borderline significance (p = 0.072). The pooled 1- and 3-year RFS rates were 40.0% (95% CI, 33.6-46.4%) and 19.2% (95% CI, 8.4-32.7%). The pooled 1-, 3-, and 5-year TTLTP rates were 79.3% (95% CI, 65.1-90.9%), 59.5% (95% CI, 49.1-69.4%), and 58.2% (95% CI, 44.9-70.9%). The pooled incidence of major complications was 5.7% (95% CI, 4.1-7.8%). Tumor size (> 3 cm), multiple tumors, and age (> 65 years) were factors associated with shorter OS.

CONCLUSION

Thermal ablation is a successful alternative with a good safety profile, especially for a single ICC smaller than 3 cm.

KEY POINTS

• The pooled 1-, 3-, and 5-year OS rates following thermal ablation for the treatment of intrahepatic cholangiocarcinoma were 82.4%, 42.1%, and 28.5%. • The pooled incidence of major complications was 5.7%. • A tumor size > 3 cm (HR: 2.12, p = 0.006), multiple tumors (HR: 1.67, p = 0.004), and age > 65 years (HR: 1.67, p = 0.006) were factors associated with shorter OS.