Proposed modification of the eighth edition of the AJCC staging system for intrahepatic cholangiocarcinoma

Establishment and Characterization of a New Intrahepatic Cholangiocarcinoma Cell Line, ICC-X2

Background

Intrahepatic cholangiocarcinoma (ICC) is an aggressive malignant tumor of the biliary tract that is prone to recurrence and metastasis and is characterized by poor sensitivity to chemotherapy and overall prognosis. For these reasons, there is an urgent need to understand its pathological mechanisms and develop effective treatments. To address this challenge, the establishment of suitable preclinical models is critical.

Methods

Fresh ICC tissue samples were used for primary culture and subculture. The cell line was evaluated by cell proliferation assays, clonal formation assays, karyotype analysis, and short tandem repeat (STR) analysis. Drug resistances against oxaliplatin, paclitaxel, gemcitabine and 5-fluorouracil (5-FU) were evaluated by CCK-8 assay. Subcutaneous injection of 1 × 106 cells to three BALB/c nude mice was conducted for xenograft studies. The hematoxylin and eosin (H&E) staining was used to detect the pathological status of the cell line. The expression of biomarkers CK7, CK19, Ki-67, E-cadherin and vimentin was determined by immunocytochemistry assay.

Results

A new ICC cell line named ICC-X2 was successfully established. Like ICC-X3 established using the same patient's metastatic tumor, the cell line has been continuously cultured in vitro for more than a year and has been passaged more than 100 times. ICC-X2 retained the typical biliary epithelial morphology. The population doubling time of ICC-X2 is 48 h. The cells demonstrated an abnormal nearly tetraploid karyotype. The STR analysis confirmed that ICC-X2 was highly consistent with the primary tumor tissue and not cross-contaminated by existing cell lines. ICC-X2 cells positively expressed CK7, CK19, E-cadherin, and vimentin, and the positive expression of Ki-67 in ICC-X2 cells was 40%. The ICC-X2 cells exhibited a strong clonogenic ability. The drug sensitivity test indicated that ICC-X2 was sensitive to oxaliplatin and paclitaxel, but naturally resistant to gemcitabine and 5-FU. ICC-X2 was rapidly able to form transplanted tumors in vivo after subcutaneous inoculation in nude mice.

Conclusions

ICC-X2 is an excellent experimental model that can be used for studying the occurrence, development, and metastasis of ICC and investigating the mechanism of tumor drug resistance.

CS-iCCA, A New Clinically Based Staging System for Intrahepatic Cholangiocarcinoma: Establishment and External Validation

INTRODUCTION

Intrahepatic cholangiocarcinoma (iCCA) is a primary liver malignancy with poor prognosis. Current prognostic methods are most accurate for patients with surgically resectable disease. However, a significant proportion of patients with iCCA are not surgical candidates. We aimed to develop a generalizable staging system based on clinical variables to determine prognosis of all patients with iCCA.

METHODS

The derivation cohort included 436 patients with iCCA seen between 2000 and 2011. For external validation, 249 patients with iCCA seen from 2000 to 2014 were enrolled. Survival analysis was performed to identify prognostic predictors. All-cause mortality was the primary end point.

RESULTS

Eastern Cooperative Oncology Group status, tumor number, tumor size, metastasis, albumin, and carbohydrate antigen 19-9 were incorporated into a 4-stage algorithm. Kaplan-Meier estimates for 1-year survival were 87.1% (95% confidence interval [CI] 76.1-99.7), 72.7% (95% CI 63.4-83.4), 48.0% (95% CI 41.2-56.0), and 16% (95% CI 11-23.5), respectively, for stages I, II, III, and IV. Univariate analysis yielded significant differences in risk of death for stages II (hazard ratio [HR] 1.71; 95% CI 1.0-2.8), III (HR 3.32; 95% CI 2.07-5.31), and IV (HR 7.44; 95% CI 4.61-12.01) compared with stage I (reference). Concordance indices showed the new staging system was superior to the TNM staging for predicting mortality in the derivation cohort, P < 0.0001. In the validation cohort, however, the difference between the 2 staging systems was not significant.

DISCUSSION

The proposed independently validated staging system uses nonhistopathologic data to successfully stratify patients into 4 stages. This staging system has better prognostic accuracy compared with the TNM staging and can assist physicians and patients in treatment of iCCA.

Tspan15-ADAM10 signalling enhances cancer stem cell-like properties and induces chemoresistance via Notch1 activation in ICC

BACKGROUND & AIMS

Notch1 activation promotes ICC progression and is associated with chemoresistance; however, therapies directly targeting Notch1 showed severe adverse effects. Notch1 activation is mediated by ADAM10, a molecular scissor that separates the target protein from its substrates in the cell membrane. Tspan15 regulates ADAM10 function, but the role of Tspan15 in ICC progression is unclear.

METHODS

Tspan15, ADAM10, and Notch1 expression and activation in fresh surgical specimens from 80 ICC patients and ICC cells were evaluated by immunohistochemistry, RT-PCR, western blotting, and flow cytometry.

RESULTS

Tspan15 expression was increased in ICC compared with adjacent liver tissue, and high Tspan15 expression was an independent factor for poor prognosis. In ICC with high Tspan15 expression, vascular invasion, lymph node metastasis, and haematogenous recurrence were increased. Tspan15 was co-expressed with ADAM10 in ICC, and associated with the expression of stemness and EMT markers. In ICC cells, Tspan15 induced ADAM10 activation by mediating the translocation of activated m-ADAM10 from the cytoplasm to the surface of the cell membrane, which further activated Notch1 by separating the intracellular domain of Notch1 from its extracellular domain, leading to enhancement of CSC-like properties and EMT. This signalling was associated with enhanced chemoresistance against gemcitabine and cisplatin. Inhibition of Tspan15 or ADAM10 is a promising therapeutic strategy in ICC, as Tspan15 or ADAM10 knockdown or treatment with ADAM10 inhibitor reduced chemoresistance and invasiveness by suppressing Notch1-mediated CSC-like properties and EMT.

CONCLUSIONS

Tspan15-ADAM10-Notch1 signalling is associated with aggressive tumour progression and poor prognosis in ICC.

Competing risks analysis of external versus internal radiation in patients with hepatocellular carcinoma after controlling for immortal time bias

PURPOSE

In cohort studies on liver cancer, there are often immortal time bias and interference of competing risk events. This study proposes to explore the role of internal and external radiotherapy for hepatocellular carcinoma using SEER data, using a competing risk model and controlling immortal time bias.

METHODS

Data of SEER from 2004 till 2015 was included. To analyze whether there was a difference in survival between HCC (hepatocellular carcinoma) patients receiving external radiation and internal radiation, we used a competing risk analysis after excluding immortal time bias, and created a nomogram to assess the risk of cancer-specific death (CSD) in hepatocellular carcinoma patients receiving radiotherapy.

RESULTS

Potential confounding factors adjusted, there was no significant difference in CSD between external and internal radiation therapy [HR and its 95% CI = 1.098 (0.874-1.380)]. The constructed nomogram performed better than the traditional AJCC model. The AUC and calibration curve results showed that this well-calibrated nomogram could be used to make clinical decisions regarding the prognosis and personalized treatment of hepatocellular carcinoma treated. There was no difference in the cumulative risk of death between patients with liver cancer treated with external radiation therapy and internal radiation therapy.

CONCLUSION

There is no difference in the cumulative risk of death between patients with liver cancer treated with external radiation therapy and internal radiation therapy. The nomogram predicts the results more accurately. These results can be used to guide the choice of treatment options for patients with HCC and to predict their survival prognosis.

Combined Tumor Burden Score and Carbohydrate Antigen 19-9 Grading System to Predict Outcomes Among Patients with Intrahepatic Cholangiocarcinoma

BACKGROUND

The interplay of carbohydrate antigen 19-9 (CA19-9) and tumor burden score (TBS) within intrahepatic cholangiocarcinoma remains ill-defined. We evaluated the roles of TBS and CA19-9 relative to overall survival (OS) and recurrence, as well as the predictive ability of the combined TBS and CA19-9 (CTC) grading system.

STUDY DESIGN

Patients undergoing liver resection for intrahepatic cholangiocarcinoma between 2000 and 2020 were identified using a multi-institutional database. The impact of CA19-9 and TBS on 5-year OS and 3-year recurrence was assessed, along with the prognostic accuracy of the CTC grading system (ie the composite score of CA19-9 level and TBS).

RESULTS

Among 831 patients, the median age was 58.2 years and 482 (58.0%) were male. The median [IQR] CA19-9 level was 49.7 [17.0, 221.0] U/mL and TBS was 6.1 [4.1, 8.3]. Median [IQR] and 5-year OS were 36.9 [32.3, 43.1] months and 38.9%, respectively; 3-year recurrence was 68.9%. Five-year survival varied relative to CA19-9 (low vs high, 49.0% vs 19.7%) and TBS (low vs high, 53.6% vs 26.9%) (p < 0.001 for both). On multivariable analysis, high CA19-9 (hazard ratio [HR] 2.02, 95% CI 1.64 to 2.49) and high TBS (HR 1.64, 95% CI 1.32 to 2.06) remained independently associated with OS. In turn, the CTC grading score stratified 5-year OS (low vs intermediate vs high CTC, 57.7% vs 39.9% vs 12.6%; p < 0.001) and remained an independent prognostic factor (referent, low CTC; [intermediate CTC] HR 1.54, 95% CI 1.18 to 2.01; [high CTC] HR 3.28, 95% CI 2.47 to 4.36).

CONCLUSIONS

The interplay between tumor morphology and biology dictates long-term prognosis after liver resection for intrahepatic cholangiocarcinoma. Prognostic models such as the CTC grading system may inform discussions around prognosis, as well as help identify which patients with ICC may benefit more from neoadjuvant chemotherapy rather than up-front surgery.

Application of Hazard Function to Investigate Recurrence of Intrahepatic Cholangiocarcinoma After Curative-Intent Liver Resection: A Novel Approach to Characterize Recurrence

PURPOSE

To investigate recurrence patterns after surgery for intrahepatic cholangiocarcinoma (ICC) relative to lymph node status, tumor extension, tumor burden score (TBS), and adjuvant chemotherapy.

METHODS

Patients who underwent curative-intent resection for ICC from 1990 to 2020 were enrolled from a multi-institutional database. The hazard function was applied to plot the hazard rates over time, with further stratification by T and N AJCC 8th edition categories, TBS, and adjuvant chemotherapy.

RESULTS

A total of 1192 patients underwent curative-intent resection for ICC and 59.9% experienced recurrence. Overall, the peak of recurrence occurred at 6.6 months. Among patients with negative lymph nodes, the T4-category had a higher peak rate of recurrence (0.1199 at 10.2 months) compared with other T-categories, while high TBS had an earlier peak of recurrence (4.2 months) compared with lower TBS. Among patients with N1 disease, T2-T4 categories had multipeak patterns of recurrence with higher hazard rates during the first 3 years after surgery in comparison with T1-category, while patients with high TBS had an earlier (4.0 months) and higher hazard peak rate compared with lower TBS groups. The administration of adjuvant chemotherapy was associated with delayed hazard rates of recurrence for N1 (4 months) and NX (6 months) categories.

DISCUSSION

The novel application of the hazard function to assess hazard rates and timing patterns of recurrence following resection for ICC demonstrated that recurrence varied based on T- and N-categories, as well as TBS. Hazard function-based recurrence data may be helpful to tailor counseling, surveillance, and adjuvant therapy recommendations.

Prognostic influence of multiple hepatic lesions in resectable intrahepatic cholangiocarcinoma: A systematic review and meta-analysis

BACKGROUND

Presence of multiple hepatic lesions in intrahepatic cholangiocarcinoma (iCCA) is included in staging as a negative prognostic factor, but both prognostic value and therapeutic implications remain debated. The aim of this study was to systematically review the prognostic influence of multiple lesions on survival after resection for iCCA, with stratification for distribution and number of lesions.

METHODS

Medline and Embase were systematically searched to identify records (2010-2021) reporting survival for patients undergoing primary resection for iCCA. Included were original articles reporting overall survival, with data on multiple lesions including tumour distribution (satellites/other multiple lesions) and/or number. For meta-analysis, the random effects model and inverse variance method were used. PRISMA 2020 guidelines were followed.

RESULTS

Thirty-one studies were included for review. For meta-analysis, nine studies reporting data on the prognostic influence of satellite lesions (2737 patients) and six studies reporting data on multiple lesions other than satellites (1589 patients) were included. Satellite lesions (hazard ratio 1.89, 95% confidence interval 1.67-2.13) and multiple lesions other than satellites (hazard ratio 2.41, 95% confidence interval 1.72-3.37) were significant negative prognostic factors. Data stratified for tumour number, while limited, indicated increased risk per additional lesion.

CONCLUSION

Satellite lesions, as well as multiple lesions other than satellites, was a negative prognostic factor in resectable iCCA. Considering the prognostic impact, both tumour distribution and number of lesions should be evaluated together with other risk factors to allow risk stratification for iCCA patients with multiple lesions, rather than precluding resection for the entire patient group.

Challenges and Opportunities for Treating Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is one of the rarest and most aggressive types of cancer. The symptoms of ICC patients can be vague, leading to late diagnosis and dismal prognosis. In this review, we investigated the treatment options for ICC, as well as ways to overcome challenges in identifying and treating this disease. Imaging remains the gold standard to diagnose ICC. Patients are staged based on the tumor, nodes and metastases (TNM) staging system. Patients eligible for surgical resection should undergo surgery with curative intent with the goal of microscopically disease-free margins (R0 resection) along with lymphadenectomy. Minimal invasive surgery (MIS) and liver transplantation have recently been offered as possible ways to improve disease outcomes. ICC recurrence is relatively common and, thus, most patients will need to be treated with systemic therapy. Several clinical trials have recently investigated the use of neoadjuvant (NT) and adjuvant therapies for ICC. NT may offer an opportunity to downsize larger tumors and provide patients, initially ineligible for surgery, with an opportunity for resection. NT may also treat occult micro-metastatic disease, as well as define tumor biology prior to surgical resection, thereby decreasing the risk for early postoperative recurrence. Adjuvant systemic therapy may improve outcomes of patients with ICC following surgery. Ongoing clinical trials are investigating new targeted therapies that hold the hope of improving long-term outcomes of patients with ICC.