Comprehensive Molecular Characterization of Gallbladder Carcinoma and Potential Targets for Intervention

Adenomyoma/adenomyomatosis-associated mural intracholecystic neoplasms: analysis of clinico-pathologic, imaging, and molecular features of a consecutive case series

Adenomyoma/adenomyomatosis (AM) of the gallbladder is generally considered an incidental and innocuous finding; however, neoplastic lesions, including intracholecystic neoplasms (ICNs), flat-type dysplasia, and carcinomas, may arise within AM. AM-associated ICNs, composed of mural cystically dilated glands containing florid papillary proliferations lined by mucinous and/or overtly dysplastic epithelium, are very rare and poorly characterized. This study aimed at investigating the clinico-radiologic, phenotypic/immunophenotypic, and molecular features of a mono-institutional case series of four AM-ICNs (0.2% of cholecystectomies). Immunohistochemistry for CDX2, MUC2, MUC5AC, MUC6, MUC1, HER2, ß-catenin, and p53, as well as next-generation sequencing of 110 tumor-related genes (AmoyDx® Comprehensive Panel), were performed. Our study confirms the AM-ICN-associated clinico-demographic characteristics previously described, including the relatively low frequency of associated invasive carcinoma (one case, 25%), although high-grade dysplasia (HGD) was observed in three out of four cases. In two cases, imaging findings suspicious for neoplasm were seen. Segmental-type AM was seen in two cases. Predominantly cell phenotype was gastric foveolar in two AM-ICNs and pancreatobiliary in the other two cases (both with HGD), while the immunophenotype was hybrid/mixed in all cases. No case had nuclear ß-catenin expression nor Wnt pathway or KRAS gene alterations. One case showed both HER2 point mutation and HER2 amplification, while the AM-ICN associated with an invasive adenocarcinoma harbored TP53 mutation and p53 overexpression. In conclusion, our findings suggest the separation of AM-ICNs from other gallbladder dysplastic lesions.

Insights into targeting LKB1 in tumorigenesis

Genetic alterations to serine-threonine kinase 11 (STK11) have been implicated in Peutz-Jeghers syndrome and tumorigenesis. Further exploration of the context-specific roles of liver kinase B1 (LKB1; encoded by STK11) observed that it regulates AMP-activated protein kinase (AMPK) and AMPK-related kinases. Given that both migration and proliferation are enhanced with the loss of LKB1 activity combined with the prevalence of STK11 genetic alterations in cancer biopsies, LKB1 was marked as a tumor suppressor. However, the role of LKB1 in tumorigenesis is paradoxical as LKB1 activates autophagy and reactive oxygen species scavenging while dampening anoikis, which contribute to cancer cell survival. Due to the pro-tumorigenic properties of LKB1, targeting LKB1 pathways is now relevant for cancer treatment. With the recent successes of targeting LKB1 signaling in research and clinical settings, and enhanced cytotoxicity of chemical compounds in LKB1-deficient tumors, there is now a need for LKB1 inhibitors. However, validating LKB1 inhibitors is challenging as LKB1 adaptor proteins, nucleocytoplasmic shuttling, and splice variants all manipulate LKB1 activity. Furthermore, STE-20-related kinase adaptor protein (STRAD) and mouse protein 25 dictate LKB1 cellular localization and kinase activity. For these reasons, prior to assessing the efficacy and potency of pharmacological candidates, the functional status of LKB1 needs to be defined. Therefore, to improve the understanding of LKB1 in physiology and oncology, this review highlights the role of LKB1 in tumorigenesis and addresses the therapeutic relevancy of LKB1 inhibitors.

Clinicopathologic and molecular characteristics of neuroendocrine carcinomas of the gallbladder

Gallbladder neuroendocrine carcinomas (GB-NECs) are a rare subtype of malignant gallbladder cancer (GBC). The genetic and molecular characteristics of GB-NECs are rarely reported. This study aims to assess the frequency of microsatellite instability (MSI) in GB-NECs and characterize their clinicopathologic and molecular features in comparison with gallbladder adenocarcinomas (GB-ADCs). Data from six patients with primary GB-NECs and 13 with GB-ADCs were collected and reevaluated. MSI assay, immunohistochemistry for mismatch repair proteins (MLH1, MSH2, MSH6, and PMS2), comprehensive genomic profiling (CGP) via next-generation sequencing (NGS), and evaluation of tumor mutation burden (TMB) were conducted on these samples. The six GB-NEC cases were all female, with a mean age of 62.0±9.2 years. Of these, two cases were diagnosed as large cell neuroendocrine carcinomas (LCNECs), while the remaining four were small cell neuroendocrine carcinomas (SCNECs). Microsatellite states observed in both GB-NECs and GB-ADCs were consistently microsatellite stable (MSS). Notably, TP53 (100%, 6/6) and RB1 (100%, 6/6) exhibited the highest mutation frequency in GB-NECs, followed by SMAD4 (50%, 3/6), GNAS (50%, 3/6), and RICTOR (33%, 2/6), with RB1, GNAS, and RICTOR specifically present in GB-NECs. Immunohistochemical (IHC) assays of p53 and Rb in the six GB-NECs were highly consistent with genetic mutations detected by targeted NGS. Moreover, no statistical difference was observed in TMB between GB-NECs and GB-ADCs (p=0.864). Although overall survival in GB-NEC patients tended to be worse than in GB-ADC patients, this difference did not reach statistical significance (p=0.119). This study has identified the microsatellite states and molecular mutation features of GB-NECs, suggesting that co-mutations in TP53 and RB1 may signify a neuroendocrine inclination in GB-NECs. The IHC assay provides an effective complement to targeted NGS for determining the functional status of p53 and Rb in clinical practice.

Epidemiology and genomic features of biliary tract cancer and its unique features in Korea

Biliary tract cancer (BTC) is a rare but highly aggressive malignancy that includes intrahepatic cholangiocarcinoma (ICC), extrahepatic cholangiocarcinoma, and gallbladder cancer (GBC). While BTC has a low global incidence, its regional variations are notable. Among nations, Korea has the second-highest incidence of BTC globally, with the highest mortality rate worldwide, underscoring the need for a deeper understanding of this cancer. Liver fluke infection and hepatitis B virus infection are key risk factors unique to Korea, contributing to regional differences in BTC incidence. Additionally, genomic alterations in Korean patients with BTC differ from those in other populations, including lower frequencies of IDH1 mutations and FGFR2 fusions in ICC and a higher prevalence of ERBB2 amplification in GBC. Recognizing the clinical significance of these alterations, ivosidenib and pemigatinib have been approved in Korea for BTC patients with IDH1 mutations and FGFR2 fusions, respectively. This review explores the epidemiology, risk factors, and molecular features of BTC, along with corresponding targeted therapies. Furthermore, we compare the unique characteristics of BTC in Korea with global data to inform future research and clinical practice.

Mismatch repair (MMR) and microsatellite instability (MSI) phenotypes across solid tumors: A comprehensive cBioPortal study on prevalence and prognostic impact

Mismatch repair deficiency (MMR-d) and microsatellite instability (MSI) are prognostic and predictive biomarkers in oncology. Current testing for MMR/MSI relies on immunohistochemistry (IHC) for MMR proteins and molecular assays for MSI detection. This combined diagnostic strategy, however, lacks tumor specificity and does not account for gene variants. This study provides an in-depth analysis of MMR mutations frequency, spectrum, and distribution in solid tumors. Data from 23,893 patients across 11 tumor types, using 66 publicly available studies, were analyzed. MMR-mutated (MMR-m) status was defined by alterations in MLH1, PMS2, MSH2, and/or MSH6; MSI was assessed by MSIsensor. Cases with indeterminate labelling were excluded. Survival was analyzed using the Kaplan-Meier method. Among 19,353 tumors, 949 MMR variants were identified, comprising 432 pathogenic and 517 variants of unknown significance (VUS), as defined by OncoKB. MSH6 mutations were the most frequent (n = 279, 29.4 %), followed by MSH2 (n = 198, 20.9 %), MLH1 (n = 187, 19.7 %), and PMS2 (n = 161, 16.9 %). MMR-m cases were more frequent in endometrial (EC, 20.5 %), colorectal (CRC, 8.2 %), bladder (BLCA, 8.7 %), and gastroesophageal cancers (GEC, 5.4 %). Pathogenic mutations were more common than non-pathogenic in EC, CRC, and GEC (p < 0.001, p = 0.01, p = 0.32, respectively). MMR-m status was not associated with MSI in 247 (48.9 %) cases, including 67 (13.2 %) with pathogenic mutations. The highest concordance between MMR-m and MSI was observed in CRC (65.7 %), EC (91.2 %), and GEC (69.6 %), while the lowest in pancreatic (0.2 %) and lung cancers (0.1 %). MMR-m GECs showed improved overall survival compared to MMR-wt (p = 0.009), a relationship not observed in other tumor types. This study demonstrates that the MMR spectrum is extremely hetoerogeneous in solid tumors, highliting the need for comprehensive and tumor-specific testing strategies.

Demographic and temporal variations in gallbladder adenocarcinoma and neuroendocrine carcinoma: insights from a retrospective analysis of the national cancer database

INTRODUCTION

Gallbladder adenocarcinoma is the most common histologic subtype of gallbladder malignancies. In contrast, gallbladder neuroendocrine carcinomas are rare and poorly studied. This study aims to identify the demographic variables that may be associated with each histologic subtype.

METHODS

A retrospective analysis was conducted on 53,447 patients diagnosed with gallbladder neoplasms using data from the National Cancer Database (NCDB) between 2011 and 2020. Associations between demographic variables and the incidence of gallbladder adenocarcinoma and neuroendocrine carcinoma were compared using chi-square tests and post hoc analyses.

RESULTS

A total of 51,694 (96.7%) patients had adenocarcinoma, and 1753 (3.3%) had neuroendocrine histologic subtypes. The comparative analysis revealed significant associations with age, gender, and race (p < 0.05). Neuroendocrine carcinoma patients were diagnosed at a younger age compared to those with adenocarcinoma (z = 14.7). Moreover, patients with privately managed insurance had a higher likelihood of neuroendocrine carcinoma (z = 5.7), while those with Medicare were less likely (z = - 4.7). Gender differences were also notable; males were more predisposed to neuroendocrine carcinoma (z = 4.4, OR = 1.3), while females were less so (z = - 3.1). A significant increase in neuroendocrine cases was observed after 2016 (z = 2.4), while the incidence of adenocarcinoma subtypes was stable. Notable racial disparities in the diagnosis of gallbladder cancer were identified with black patients more likely to have neuroendocrine carcinoma.

CONCLUSION

This study highlights the differences in demographic and clinical characteristics of patients diagnosed with gallbladder neuroendocrine carcinomas compared to adenocarcinoma tumors. These findings highlight potential opportunities for targeted screening programs to enhance early detection efforts.

Genomic and transcriptomic signatures of sequential carcinogenesis from papillary neoplasm to biliary tract cancer

BACKGROUND & AIMS

Papillary neoplasms of the biliary tree, including intraductal papillary neoplasms (IPNs) and intracholecystic papillary neoplasms (ICPNs), are recognized as precancerous lesions. However, the genetic characteristics underlying sequential carcinogenesis remain unclear.

METHODS

Whole-exome sequencing was performed on 166 neoplasms (33 intrahepatic IPNs, 44 extrahepatic IPNs, and 89 ICPNs), and 41 associated carcinomas. Nine available cases were also subjected to spatial transcriptomic analysis.

RESULTS

Mutations in the MAPK (48%), genomic integrity maintenance (42%), and Wnt/β-catenin (33%) pathways were prevalent in intrahepatic IPNs, extrahepatic IPNs, and ICPNs, respectively. KRAS mutations were enriched in intrahepatic IPNs (42%, p <0.001), whereas SMAD4 mutations were enriched in extrahepatic IPNs (21%, p = 0.005). ICPNs frequently exhibit CTNNB1 mutations, particularly in low-grade lesions. Mutational signature analysis revealed that SBS1 and SBS5 signatures were homogeneously enriched in intrahepatic IPNs, in contrast to the heterogeneous distribution of SBS1, SBS2, SBS5, SBS13, SBS7b, and SBS23 in extrahepatic IPNs and ICPNs. Copy number aberrations gradually increased from low-to high-grade intraepithelial neoplasia and eventually to carcinoma. Phylogenetic analysis revealed that 89% of carcinomas were derived from IPNs/ICPNs through sequential carcinogenesis, with the majority sharing driver mutations between the IPN/ICPN and the carcinoma. Furthermore, multifocal, independent carcinogenesis events were observed in IPNs/ICPNs, resulting in mutationally distinct carcinoma lesions. Carcinogenesis of IPN/ICPN occurs in multiple subclones through mutational accumulation and transcriptomic alterations that affect vascular development, cell morphogenesis, extracellular matrix organization, and growth factor response.

CONCLUSIONS

With the largest IPN/ICPN cohort reported to date, our study provides a genome- and spatial transcriptome-level portrait of sequential carcinogenesis and differences in the anatomical location of biliary papillary neoplasms.

IMPACT AND IMPLICATIONS

Biliary tract cancer is a fatal malignancy. However, the genome-level sequential progression from intraepithelial neoplasia to carcinoma has not yet been evaluated in a sufficiently large cohort. Papillary lesions of the bile duct and gallbladder are collectively termed intraductal papillary neoplasms of the bile duct and intracholecystic papillary neoplasms, respectively. They are primarily diagnosed based on histopathological studies. This study provides a comprehensive mutational and spatial transcriptomic landscape of papillary neoplasms of the bile duct and gallbladder. The results of this study offer insights into the mechanism of sequential carcinogenesis in papillary biliary tract tumors, pathology-genomic correlations, and potential therapeutic targets.

Clinicopathologic and genomic characteristics of biliary tract carcinomas with TERT promoter mutations among East Asian population

Telomerase reverse transcriptase gene promoter (TERT) mutations are biomarkers that predict survival and responses to immune checkpoint inhibitors in various malignancies. However, their prevalence and clinicopathologic characteristics in biliary tract carcinomas are largely unknown. We performed a comprehensive genomic profiling of formalin-fixed paraffin-embedded tumor tissue from 485 carcinomas, including intrahepatic (n = 220), perihilar (n = 54), distal biliary tract (n = 110), and gallbladder (n = 101) cancers, using next-generation sequencing. TERT mutations were observed in 50 out of 485 biliary tract cancers (10.3 %) consisting of 39 C228T (78.0 %) and 11 C250T (22.0 %) variants. Among the different anatomic locations, TERT mutations were most frequent in the gallbladder (20.8 %), followed by perihilar (9.3 %), intrahepatic (7.7 %), and distal bile ducts (6.4 %) (p < 0.01). Genetically, TERT mutations were significantly associated with TP53 mutations (p = 0.04), ERBB2 amplification (p < 0.01), and high tumor mutational burdens (TMB) (p < 0.01); moreover, they were negatively correlated with KRAS (p < 0.01), SMAD4 (p = 0.01), and PBRM1 mutations (p = 0.01). In addition, TERT mutations were associated with a poor progression-free survival (PFS, p = 0.01). Specifically, in cases of intrahepatic cholangiocarcinoma, TERT mutations were more frequent in patients with cirrhosis (p = 0.01), hepatitis B virus infection (p = 0.04), and advanced disease stages (p < 0.01). In gallbladder carcinoma, TERT mutations were also associated with poor PFS. In conclusion, TERT mutations in biliary tract carcinomas had unique clinicopathologic and genetic characteristics. Despite its poor PFS, the concomitant presence of ERBB2 amplification and a high TMB indicated a potential for targeted therapy and immunotherapy in this specific subtype.

Deep Vein Thrombosis as a Complication of Gemcitabine-Capecitabine Chemotherapy in Adenocarcinoma of Gallbladder

Gallbladder adenocarcinoma has a high mortality rate, with approximately 1.7% cancer-related deaths worldwide. Cancer-associated thrombosis (CAT), including deep vein thrombosis (DVT), can significantly increase the risk of mortality within cancer patients, especially in pancreatic, brain, and intra-abdominal cancers, as well as in advanced and metastatic cancers. In this case report, there was a 45-year-old male patient diagnosed with advanced gallbladder adenocarcinoma UICC stage IVB with a TNM stage of T2b, N0, M1 with liver metastases who experienced pain and swelling in both lower limbs after undergoing a VI-A cycle of chemotherapy with gemcitabine capecitabine. The risk of thrombosis was calculated using the modified Khorana-Vienna CAT scores, which increased during every chemotherapy session. In this case, the Khorana-Vienna CAT score was calculated during two latest cycle of chemotherapy that somewhat considered delayed as the patient had already shown hypercoagulopathy symptoms and developed a poorer prognosis. Early CAT scoring, ideally before starting chemotherapy session, potentially improves thrombosis prognosis. The patient's condition improved after administration of antithrombotic agents. Chemotherapy agents and other factors, including the cancer site and presence of metastatic cancer, influence the risk of CAT. Risk predictor scores are required to assess the risk of CAT and benefits of prophylactic treatment. Prophylactic therapy can be initiated in patients with high-risk CAT, calculated using the modified Khorana and Vienna CAT scores, to prevent thrombosis and improve patient outcomes.

Super-Enhancer Reprograming Driven by SOX9 and TCF7L2 Represents Transcription-Targeted Therapeutic Vulnerability for Treating Gallbladder Cancer

Gallbladder cancer (GBC) is a highly aggressive malignancy lacking clinically available targeted therapeutic agents. Super-enhancers (SEs) are crucial epigenetic cis-regulatory elements whose extensive reprogramming drives aberrant transcription in cancers. To study SE in GBC, the genomic distribution of H3K27ac is profiled in multiple GBC tissue and cell line samples to establish the SE landscape and its associated core regulatory circuitry (CRC). The biliary lineage factor SOX9 and Wnt pathway effector TCF7L2, two master transcription factor (TF) candidates identified by CRC analysis, are verified to co-occupy each other's SE region, forming a mutually autoregulatory loop to drive oncogenic SE reprogramming in a subset of GBC. The SOX9/TCF7L2 double-high GBC cells are highly dependent on the two TFs and enriched of SE-associated gene signatures related to stemness, ErbB and Wnt pathways. Patients with more such GBC cells exhibited significantly worse prognosis. Furthermore, SOX9/TCF7L2 double-high GBC preclinical models are found to be susceptible to SE-targeted CDK7 inhibition therapy in vitro and in vivo. Together, this study provides novel insights into the epigenetic mechanisms underlying the oncogenesis of a subset of GBCs with poorer prognosis and illustrates promising prognostic stratification and therapeutic strategies for treating those GBC patients in future clinical trials.

Newer Biomarkers in Gallbladder Carcinoma: A Scoping Review

Biomarkers have the potential to play a crucial role in managing gallbladder cancer post-surgery. They can identify patients more likely to experience a recurrence, allowing oncologists to tailor a more intensive surveillance plan and consider additional therapies. Some biomarkers can even predict how well a patient will respond to specific chemotherapy or targeted treatments. By monitoring these biomarkers, clinicians can track how effective the ongoing treatment is and detect any signs of early recurrence. Various biomarkers, like tumor markers, genetic markers, and genomic and epigenetic markers, are being investigated. The goal is to find the most reliable and accurate biomarkers to enhance patient care and outcomes. Integrating biomarker data into treatment plans can help personalize therapy and make better informed decisions. By identifying which patients are likely to benefit from specific treatments, biomarkers have the potential to improve long-term survival rates significantly. This scoping review discusses newer biomarkers in gallbladder carcinoma; some of them are in clinical use, while most of them are used in research settings. This provides a broad insight to practicing clinicians about the present biomarkers and the futuristic biomarkers.

A Case of Advanced Biliary Tract Cancer With EGFR Amplification That Responded to Necitumumab

BACKGROUND

Recent advances in cancer genome analysis and the practice of precision medicine have made it possible to identify fractions with rare genetic alterations. Among biliary tract cancers, EGFR-amplified cancers are known to be rare fractions across organs and have a poor prognosis. The use of anti-EGFR antibody for EGFR-amplified cancers has been promising; however, the evidence is not yet clear.

CASE

In this report, we describe the case of a 48-year-old man diagnosed with advanced gallbladder cancer. The patient was administered gemcitabine plus cisplatin, followed by S-1 monotherapy; however, disease progression was observed after two cycles of each regimen. Comprehensive genomic profiling test revealed EGFR-amplification, and the patient was treated with combination therapy with the anti-EGFR antibody necitumumab, gemcitabine, and cisplatin. After two cycles of treatment, tumor size reduced, and the treatment response was evaluated as partial response. On Day 90, after five cycles of treatment, tumor progression was confirmed. In addition, after disease progression, liquid biopsy revealed acquired pathogenic gene alterations suggesting anti-EGFR antibody resistance.

CONCLUSION

This report supports the clinical benefit of anti-EGFR antibodies for EGFR-amplified biliary tract cancers and the importance of genomic analysis in personalized therapy and drug resistance research.

The Epidemiology of Biliary Tract Cancer and Associated Prevalence of MDM2 Amplification: A Targeted Literature Review

Biliary tract cancer (BTC) is a rare and aggressive malignancy that is anatomically classified as gallbladder cancer (GBC), extra- and intra-hepatic cholangiocarcinoma (eCCA and iCCA) and ampullary cancer (AC). BTC is often diagnosed at an advanced stage when treatment options are limited and patients have a poor prognosis, so the identification of new drug targets is of critical importance. BTC is molecularly diverse and harbours different therapeutically actionable biomarkers, including mouse double minute 2 homolog (MDM2), which is currently being investigated as a drug target. The aim of this targeted review was to evaluate and synthesise evidence on the epidemiology of BTC and its subtypes in different geographic regions and on the frequency of MDM2 amplifications in BTC tumours. Epidemiological studies (N = 33) consistently demonstrated high incidence rates in South and Central Asia for BTC overall (up to 9.00/100,000) and for all subtypes, with much lower rates in Europe and the US. Among the different types of BTC, the highest global incidence was observed for CCA, mainly driven by iCCA (1.4/100,000), followed by GBC (1.2/100,000) and AC (0.18-0.93 per 100,000). Studies of MDM2 in BTC (N = 19) demonstrated variable frequency of MDM2 amplification according to subtype, with consistently high MDM2 amplification rates in GBC (up to 17.5%), and lower rates in CCA (up to 4.4%). The results from this literature review highlight the geographic heterogeneity of BTC and the need for standardised clinicopathologic assessment and reporting to allow cross-study comparisons.

CircRNome-wide characterisation reveals the promoting role of circAATF in anti-PD-L1 immunotherapy of gallbladder carcinoma

Circular RNAs (circRNAs) have been shown to play important roles in tumour development and tumour immunology. However, genome-wide characterisation of circRNAs and their roles in the immunology and immunotherapy of gallbladder carcinoma (GBC) has been lacking. We present a comprehensive characterisation of the circRNA landscape in GBC, revealing GBC-specific circRNAs. Our analysis found that circRNAs are significantly enriched in cell proliferation and are involved in cancer-related hallmarks. In particular, circAATF was upregulated in GBC, which was positively correlated with AATF mRNA expression, and promoted GBC cell growth. Through integrating computational and experimental approaches, we revealed that circAATF is positively associated with the CD4+ T cell abundance and PD-L1 level, and enhances the clinical benefits of anti-PD-L1 immunotherapy for GBC. We further demonstrate that circAATF elevates the PD-L1 level by activating phosphorylated AKT and acting as a sponge for miR-142-5p. CircAATF is positively associated with CD4+ T cells and PD-L1 levels and shows potential to aid anti-PD-L1 immunotherapy for GBC. Our study provides insights into roles of circAATF in the tumour development and immunology of GBC and accelerates the development of therapeutic strategies for GBC immunotherapy. HIGHLIGHTS: We present a comprehensive characterisation of circRNA landscape in gallbladder carcinoma (GBC). CircAATF is positively associated with CD4+ T cell abundance and PD-L1 expression and is shown to promote PD-L1 treatment in mouse model. CircAATF can elevate PD-L1 level through phosphorylated AKT and linear AATF, which upregulates PD-L1 by acting as a sponge of miR-142-5p.

Recent Advancement in Diagnosis of Biliary Tract Cancer through Pathological and Molecular Classifications

Biliary tract cancers (BTCs), including intrahepatic, perihilar, and distal cholangiocarcinomas, as well as gallbladder cancer, are a diverse group of cancers that exhibit unique molecular characteristics in each of their anatomic and pathological subtypes. The pathological classification of BTCs compromises distinct growth patterns, including mass forming, periductal infiltrating, and intraductal growing types, which can be identified through gross examination. The small-duct and large-duct types of intrahepatic cholangiocarcinoma have been recently introduced into the WHO classification. The presentation of typical clinical symptoms, as well as the extensive utilization of radiological, endoscopic, and molecular diagnostic methods, is thoroughly detailed in the description. To overcome the limitations of traditional tissue acquisition methods, new diagnostic modalities are being explored. The treatment landscape is also rapidly evolving owing to the emergence of distinct subgroups with unique molecular alterations and corresponding targeted therapies. Furthermore, we emphasize the crucial aspects of diagnosing BTC in practical clinical settings.

MicroRNA-34a-5p: A pivotal therapeutic target in gallbladder cancer

Gallbladder cancer incidence has been increasing globally, and it remains challenging to expect long prognosis with the current systemic chemotherapy. We identified a novel nucleic acid-mediated therapeutic target against gallbladder cancer by using innovative organoid-based gallbladder cancer models generated from KrasLSL-G12D/+; Trp53f/f mice. Using comprehensive microRNA expression analyses and a bioinformatics approach, we identified significant microRNA-34a-5p downregulation in both murine gallbladder cancer organoids and resected human gallbladder cancer specimens. In three different human gallbladder cancer cell lines, forced microRNA-34a-5p expression inhibited cell proliferation and induced cell-cycle arrest at the G1 phase by suppressing direct target (CDK6) expression. Furthermore, comprehensive RNA sequencing revealed the significant enrichment of gene sets related to the cell-cycle regulators after microRNA-34a-5p expression in gallbladder cancer cells. In a murine xenograft model, locally injected microRNA-34a-5p mimics significantly inhibited gallbladder cancer progression and downregulated CDK6 expression. These results provide a rationale for promising therapeutics against gallbladder cancer by microRNA-34a-5p injection, as well as a strategy to explore therapeutic targets against cancers using organoid-based models, especially for those lacking useful genetically engineered murine models, such as gallbladder cancer.

HER2-targeted therapies in cancer: a systematic review

Abnormal alterations in human epidermal growth factor receptor 2 (HER2, neu, and erbB2) are associated with the development of many tumors. It is currently a crucial treatment for multiple cancers. Advanced in molecular biology and further exploration of the HER2-mediated pathway have promoted the development of medicine design and combination drug regimens. An increasing number of HER2-targeted drugs including specific monoclonal antibodies, tyrosine kinase inhibitors (TKIs), and antibody-drug conjugates (ADCs) have been approved by the U.S. Food and Drug Administration. The emergence of ADCs, has significantly transformed the treatment landscape for various tumors, such as breast, gastric, and bladder cancer. Classic monoclonal antibodies and novel TKIs have not only demonstrated remarkable efficacy, but also expanded their indications, with ADCs in particular exhibiting profound clinical applications. Moreover the concept of low HER2 expression signifies a breakthrough in HER2-targeted therapy, indicating that an increasing number of tumors and patients will benefit from this approach. This article, provides a comprehensive review of the underlying mechanism of action, representative drugs, corresponding clinical trials, recent advancements, and future research directions pertaining to HER2-targeted therapy.

Current Standards, Multidisciplinary Approaches, and Future Directions in the Management of Extrahepatic Cholangiocarcinoma

OPINION STATEMENT

Biliary tract cancers are molecularly and anatomically diverse cancers which include intrahepatic cholangiocarcinoma, extrahepatic (perihilar and distal) cholangiocarcinoma, and gallbladder cancer. While recognized as distinct entities, the rarer incidence of these cancers combined with diagnostic challenges in classifying anatomic origin has resulted in clinical trials and guideline recommended strategies being generalized patients with all types of biliary tract cancer. In this review, we delve into the unique aspects, subtype-specific clinical trial outcomes, and multidisciplinary management of patients with extrahepatic cholangiocarcinoma. When resectable, definitive surgery followed by adjuvant chemotherapy (sometimes with selective radiation/chemoradiation) is current standard of care. Due to high recurrence rates, there is growing interest in the use of upfront/neoadjuvant therapy to improve surgical outcomes and to downstage patients who may not initially be resectable. Select patients with perihilar cholangiocarcinoma are being successfully treated with novel approaches such as liver transplant. In the advanced disease setting, combination gemcitabine and cisplatin remains the standard base for systemic therapy and was recently improved upon with the addition of immune checkpoint blockade to the chemotherapy doublet in the recently reported TOPAZ-1 and KEYNOTE-966 trials. Second-line all-comer treatments for these patients remain limited in both options and efficacy, so clinical trial participation should be strongly considered. With increased use of molecular testing, detection of actionable mutations and opportunities to receive indicated targeted therapies are on the rise and are the most significant driver of improved survival for patients with advanced stage disease. Though these targeted therapies are currently reserved for the second or later line, future trials are looking at moving these to earlier treatment settings and use in combination with chemotherapy and immunotherapy. In addition to cross-disciplinary management with surgical, medical, and radiation oncology, patient-centered care should also include collaboration with advanced endoscopists, palliative care specialists, and nutritionists to improve global patient outcomes.

Laparoscopic vs open radical resection in management of gallbladder carcinoma: A systematic review and meta-analysis

BACKGROUND

Radical resection offers the only hope for the long-term survival of patients with gallbladder carcinoma (GBC) above the T1b stage. However, whether it should be performed under laparoscopy for GBC is still controversial.

AIM

To compare laparoscopic radical resection (LRR) with traditional open radical resection (ORR) in managing GBC.

METHODS

A comprehensive search of online databases, including Medline (PubMed), Cochrane Library, and Web of Science, was conducted to identify comparative studies involving LRR and ORR in GBCs till March 2023. A meta-analysis was subsequently performed.

RESULTS

A total of 18 retrospective studies were identified. In the long-term prognosis, the LRR group was comparable with the ORR group in terms of overall survival and tumor-free survival (TFS). LRR showed superiority in terms of TFS in the T2/tumor-node-metastasis (TNM) Ⅱ stage subgroup vs the ORR group (P = 0.04). In the short-term prognosis, the LRR group had superiority over the ORR group in the postoperative length of stay (POLS) (P < 0.001). The sensitivity analysis showed that all pooled results were robust.

CONCLUSION

The meta-analysis results show that LRR is not inferior to ORR in all measured outcomes and is even superior in the TFS of patients with stage T2/TNM Ⅱ disease and POLS. Surgeons with sufficient laparoscopic experience can perform LRR as an alternative surgical strategy to ORR.

Precision Oncology Targets in Biliary Tract Cancer

Targeted therapies in biliary tract cancer (BTC) are emerging as options for patients not who do not respond to first-line treatment. Agents acting on tumor-specific oncogenes in BTC may target fibroblast growth factor receptor 2 (FGFR2), isocitrate dehydrogenase (IDH), B-raf kinase (BRAF), and human epidermal growth factor receptor 2 (HER-2). Additionally, given the heterogeneous genetic landscape of advanced BTCs, many harbor genetic aberrations that are common among solid tumors, including RET fusions, tropomyosin receptor kinase (TRK) fusions, and high tumor mutational burden (TMB). This review aims to provide updates on the evolving array of therapeutics available, and to summarize promising works on the horizon.