Direct molecular evidence for both multicentric and monoclonal carcinogenesis followed by transdifferentiation from hepatocellular carcinoma to cholangiocarcinoma in a case of metachronous liver cancer

Accumulating Genetic Mutations from Primary to Secondary Biliary Tract Cancers: Analysis of Four Patients With Metachronous Biliary Tract Cancer Using Comprehensive Genomic Profiling

BACKGROUND/AIM

Metachronous biliary tract cancer (BTC) is a rare occurrence after curative resection of primary BTC. The genetic alterations and pathogenesis associated with metachronous BTC remain poorly understood.

PATIENTS AND METHODS

We analyzed four patients with metachronous BTC who underwent resection at the Nagoya University Hospital between 2010 and 2024. Gene panel examination was performed on both primary and secondary tumors using next-generation sequencing.

RESULTS

The median interval between resection of the primary tumor and diagnosis of metachronous BTC was 24 months. Genetic alterations were observed in all paired primary and metachronous carcinomas. The number of genetic mutations was higher in metachronous lesions than in primary lesions. CDKN2A and SMAD4 were the most frequently mutated genes in all metachronous lesions. Common genetic mutations between primary and metachronous lesions were confirmed in all four cases, suggesting a common clonal origin.

CONCLUSION

This study demonstrated that characteristic genetic alterations and their accumulation play important roles in metachronous BTC. This suggests that the increasing burden of gene mutations may play a crucial role in the carcinogenesis of metachronous BTC. Further investigation is required to validate these findings and elucidate the underlying molecular mechanisms.

Complex phenotypic heterogeneity of combined hepatocellular-cholangiocarcinoma with a homogenous TERT promoter mutation

To clarify the mechanism underlying the development and poor prognosis of combined hepatocellular-cholangiocarcinoma (cHCC-CCA), we characterized liver cancer driver mutations and poor prognostic markers in both the HCC and intrahepatic CCA (iCCA) components of a cHCC-CCA tumor. The telomerase reverse transcriptase (TERT) promoter mutation C228T was quantified by digital polymerase chain reaction using DNA from multiple microdissected cancer components of a single cHCC-CCA nodule. The protein expression of cancer-related markers, including TERT, was examined by serial thin-section immunohistochemistry and double-staining immunofluorescence. TERT promoter mutation and TERT protein expression were detected in all cancer components but not in noncancer regions. TERT promoter mutation frequencies were similar among components; those of TERT protein-positive cancer cells were higher in iCCA and mixed components than in HCC. The frequencies of Ki67- and p53-positive cells were similarly higher in iCCA and mixed components than in HCC. However, double-positive cells for the three proteins were unexpectedly rare; single-positive cells dominated, indicating phenotypic microheterogeneity in cancer cells within a component. Interestingly, HCC and CCA marker protein immunohistochemistry suggested dedifferentiation of HCC and transdifferentiation from HCC to iCCA in HCC and iCCA components, respectively. Such phenotypic intercomponent heterogeneity and intracomponent microheterogeneity were detected in a tumor nodule of cHCC-CCA uniformly carrying the early HCC driver mutation. Moreover, poor prognostic markers were randomly expressed without a regular pattern, consistent with the poor prognosis.

Multiregional analysis of combined hepatocellular-cholangiocarcinoma reveals histologic diversity and molecular clonality

Combined hepatocellular-cholangiocarcinoma (cHCC-CC) is a rare type of liver tumour that exhibits both hepatocytic and biliary differentiation within the same tumour. The histology and genomic alterations of recurrent/metastatic cHCC-CC are poorly understood. We selected six patients with cHCC-CC whose recurrent or metastatic tumours were histologically confirmed. Four patients with classic cHCC-CCs and two with intermediate cell carcinomas (ICs) were included. The clinicopathological features were evaluated, and next-generation sequencing was performed in 17 multiregional and longitudinal tumour samples. The histology of recurrent/metastatic lesions of classic cHCC-CCs was variable: hepatocellular carcinoma (HCC) was observed in one (25.0%) patient, cHCC-CC in one (25.0%) patient, and cholangiocarcinoma (CC) in two (50.0%) patients. Among 13 samples from four classic cHCC-CC patients, the most frequent pathological variants were TP53 (46.2%), TERT promoter (38.5%), ARID1A mutations (23.1%), and MET amplification (30.8%). In the sequencing analysis of each HCC and CC component, three (75.0%) of the four classic cHCC-CCs shared pathogenic variants. A large proportion of mutations, both pathogenic and those of undetermined significance, were shared by each HCC and CC component. Regarding ICs, the ATM mutation was detected in one patient. In conclusion, the histology of recurrent/metastatic cHCC-CCs was heterogeneous. Genomic profiling of classic cHCC-CCs revealed similar genomic alterations to those of HCC. Considerable overlapping genomic alterations in each HCC and CC component were observed, suggesting a monoclonal origin. Genetic alterations in ICs were different from those in either HCC or CC, suggesting the distinct nature of this tumour.

Integration analysis of miRNA-mRNA expression exploring their potential roles in intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is the second common primary hepatic malignancy tumor. In this study, an integrative analysis of differentially expressed genes (DEGs) and miRNAs from the ICC onset and adjacent normal tissues were performed to explore the regulatory roles of miRNA-mRNA interaction. A total of 1018 DEGs and 39 miRNAs were likely involved in ICC pathogenesis, suggesting the changes in cell metabolism in ICC development. The built network indicated that 30 DEGs were regulated by 16 differentially expressed miRNA. The screened DEGs and miRNA together were probably considered the biomarkers of ICC, and their important roles in ICC pathogenesis remain to be elucidated. This study could provide a good basis to uncover the regulatory mechanism of miRNA and mRNAs in ICC pathogenesis.

Long‐term efficacy of no‐touch radiofrequency ablation in the treatment of single small hepatocellular carcinoma: A single center long‐term follow‐up study

OBJECTIVE

To evaluate the long-term efficacy of no-touch radiofrequency ablation (NT-RFA) for treating single hepatocellular carcinoma (HCC) less than 3 cm.

METHODS

A total of 331 patients with HCC less than 3 cm undergoing RFA in Southwest Hospital from 2015 to 2020 were analyzed retrospectively. All patients were divided into NT-RFA group (n = 113) and conventional RFA (C-RFA) group (n = 218). The survival rate, local tumor progression (LTP) and intrahepatic distant recurrence (IDR) of the two groups were calculated and compared.

RESULTS

A significant difference was observed in ablation range (p = 0.000) and safety margin (p = 0.000) between the two groups. The 1-, 2-, 3-, 4-and 5-year overall survival (OS) rates in NT-RFA and C-RFA group were 99.12%, 93.73%, 76.18%, 57.00%, 45.17% and 99.08%, 89.91%, 71.26%, 54.28%, 41.77%, respectively. There was no significant difference between the two groups (p = 0.281). The 1-, 2-, 3-, 4-and 5-year recurrence-free survival (RFS) rates in NT-RFA and C-RFA group were 78.51%, 52.59%, 41.02%, 34.36%, 30.92% and 68.81%, 44.95%, 30.88%, 23.73%, 22.88%, respectively. The two groups differed significantly (p = 0.044). The 1-, 3-and 5-year LTP-free survival rates in NT-RFA and C-RFA group were 87.12%, 74.99%, 72.32% and 75.75%, 65.52%, 65.52%, respectively. The two groups also differed significantly (p = 0.024). Furthermore, the RFS rates of D ≤ 2 cm subgroups in NT-RFA and C-RFA groups differed significantly (p = 0.037), while the RFS rates of 2 cm < D ≤ 3 cm subgroups in two groups showed no significant difference (p = 0.578).

CONCLUSIONS

The RFS rates of single HCC less than 3 cm treated by NT-RFA was significantly higher than that of C-RFA. Due to a larger ablation range and safety margin, NT-RFA could significantly reduce LTP and improve RFS. Dual-electrode NT-RFA can significantly improve the RFS rate of patients with HCC less than 2 cm, but there is no obvious advantage compared with C-RFA in the treatment of HCC over 2 cm.

Identification of Genetic Risk Factors of Severe COVID-19 Using Extensive Phenotypic Data: A Proof-of-Concept Study in a Cohort of Russian Patients

The COVID-19 pandemic has drawn the attention of many researchers to the interaction between pathogen and host genomes. Over the last two years, numerous studies have been conducted to identify the genetic risk factors that predict COVID-19 severity and outcome. However, such an analysis might be complicated in cohorts of limited size and/or in case of limited breadth of genome coverage. In this work, we tried to circumvent these challenges by searching for candidate genes and genetic variants associated with a variety of quantitative and binary traits in a cohort of 840 COVID-19 patients from Russia. While we found no gene- or pathway-level associations with the disease severity and outcome, we discovered eleven independent candidate loci associated with quantitative traits in COVID-19 patients. Out of these, the most significant associations correspond to rs1651553 in MYH14p = 1.4 × 10^-7), rs11243705 in SETX (p = 8.2 × 10^-6), and rs16885 in ATXN1 (p = 1.3 × 10^-5). One of the identified variants, rs33985936 in SCN11A, was successfully replicated in an independent study, and three of the variants were found to be associated with blood-related quantitative traits according to the UK Biobank data (rs33985936 in SCN11A, rs16885 in ATXN1, and rs4747194 in CDH23). Moreover, we show that a risk score based on these variants can predict the severity and outcome of hospitalization in our cohort of patients. Given these findings, we believe that our work may serve as proof-of-concept study demonstrating the utility of quantitative traits and extensive phenotyping for identification of genetic risk factors of severe COVID-19.