Evolution of the Targeted Therapy Landscape for Cholangiocarcinoma: Is Cholangiocarcinoma the 'NSCLC' of GI Oncology?

Genomic landscape of biliary tract cancer and corresponding targeted treatment strategies

Biliary tract cancers (BTCs) are classified on the basis of their anatomical origin, and the feasibility of surgical resection depends on the tumor location and extent of progression. However, for unresectable BTCs, systemic therapy has been uniformly applied. Gemcitabine and cisplatin (GC) therapy and GC-based therapies were established as the first-line standard BTC treatment. However, no highly effective second-line therapy has been established, and the prognosis remains poor, highlighting the need for further therapeutic advancements. Meanwhile, the era of precision medicine has expanded the use of genetic testing, leading to the identification of actionable molecular targets in BTC. Several targeted therapies, including FGFR inhibitors and IDH1 inhibitors, have been developed, offering new second-line treatment options and the potential for first-line use in appropriate cases. Notably, the frequency of these genetic alterations varies depending on the tumor location, demonstrating the molecular heterogeneity of BTC. Therefore, it has been recognized that a tailored treatment approach for each BTC patient may be more effective than uniform systemic therapy. Consequently, although routine genetic testing before initiating systemic treatment is currently limited by the medical environment (e.g., cost, accessibility, regional differences), it is recommended in ESMO guideline and might be increasingly advocated. However, BTC harbors a wide range of genetic alterations, and numerous targeted therapies are being developed accordingly. This review provides an overview of the reported genetic alterations in BTC, the frequencies of these alterations, and the corresponding targeted therapies, emphasizing the evolving role of precision medicine in BTC treatment.

A Comprehensive Analysis of FGF/FGFR Signaling Alteration in NSCLC: Implications in Prognosis and Microenvironment

Fibroblast Growth Factor (FGF) ligands and their receptor have been identified as the potent target in non-small cell lung cancer (NSCLC). However, the clinicopathological and microenvironmental characteristics of FGF/FGFR in NSCLC remain poorly elucidated. Here, we summarize 4656 NSCLCs and analyze clinicopathological features in 478 FGF/FGFR altered cases. AI analysis and multiplex immunofluorescence staining are used to reveal microenvironment features. First, around 10.27% NSCLC carry FGF/FGFR variant. Squamous cell carcinoma (41.95%) is much more than adenocarcinoma (8.32%). In 118 pathogenic variant (PV) cases, the most frequent variant is FGF/FGFR copy number increase (83.05%), the second is FGFR gene fusion (11.86%). Surprisingly, CCND1 always co-amplifies with FGF19 (100.00%). Furthermore, FGF PV is an independent risk factor for poor outcomes (overall survival: HR = 3.781, disease-free survival: HR = 3.340). And one-third of FGFR3-TACC3 fusion cases show clear cytoplasm in histology. Either CCND1/FGF19 co-amplification or KRAS co-mutation is closely related to cigarette exposure, and KRAS co-mutation acts as an independent factor of poor prognosis. Finally, the FGF/FGFR1/NOTCH1 within RB1 variant group has a remarkably high ratio of inner-tumor CD8+ T cell infiltration, non-exhausted T cells, exhausted TCD8+PD-1+LAG3- cells, and TRM CD8+CD69+CD103+cells. Overall, this study provides a comprehensive analysis of FGF/FGFR alteration in NSCLC. The FGF/FGFR alteration mainly arises in squamous cell carcinoma. Both FGF PV and KRAS are the independent factors for poor prognosis. To our knowledge, this is the first report to describe an inflamed microenvironment recruited by NOTCH1/RB1 co-mutation, indicating potential benefit from immunotherapy.

Liver transplantation for tumor entities

PURPOSE OF REVIEW

Tumor entities represent an increasing indication for liver transplantation (LT). This review addresses the most contentious indications of LT in transplant oncology.

RECENT FINDINGS

Patient selection based on tumor biology in LT for colorectal cancer liver metastases (CRLM) demonstrated promising long-term outcomes and preserved quality of life despite high recurrence rates. In selected cases, LT for intrahepatic cholangiocarcinoma (iCCA) is feasible, with acceptable survival even in high-burden cases responsive to chemotherapy. LT following a strict neoadjuvant protocol for perihilar cholangiocarcinoma (pCCA) resulted in long-term outcomes consistently surpassing benchmark values, and potentially outperforming liver resection.

SUMMARY

While preliminary results are promising, prospective trials are crucial to define applications in routine clinical practice. Molecular profiling and targeted therapies pave the way for personalized approaches, requiring evolving allocation systems for equitable LT access.

Practical considerations for pathological diagnosis and molecular profiling of cholangiocarcinoma: an expert review for best practices

INTRODUCTION

Advances in precision medicine have expanded access to targeted therapies and demand for molecular profiling of cholangiocarcinoma (CCA) patients in routine clinical practice. However, pathologists face challenges in establishing a definitive intrahepatic CCA (iCCA) diagnosis while preserving sufficient tissue for molecular profiling. Additionally, they frequently face challenges in optimal tissue handling to preserve nucleic acid integrity.

AREAS COVERED

This article first identifies the challenges in establishing a definitive diagnosis of iCCA in a lesional liver biopsy while preserving sufficient tissue for molecular profiling. Then, the authors explore the clinical value of molecular profiling, the basic principles of single gene and next-generation sequencing (NGS) techniques, and the challenges in tissue sampling for genomic testing. They also propose an algorithm for best practice in tissue management for molecular profiling of CCA.

EXPERT OPINION

Several practical challenges face pathologists during tissue sampling and processing for molecular profiling. Optimized tissue processing, careful tissue handling, and selection of appropriate approaches to molecular testing are essential to ensure that the highest possible quality of diagnostic information is provided in the greatest proportion of cases.

Navigating uncharted territory: a case report and literature review on the remarkable response to personalized crizotinib containing combinational therapy in a pazopanib refractory patient with novel alterations

This paper presents a patient with a novel Ig-like-III domain fibroblast growth factor receptor (FGFR2) alteration (W290_P307>C) along with CDKN2A/B alterations and a cadherin 1 (CDH1) alteration. Initial responsiveness to pazopanib monotherapy was encouraging, yet progression occurred after 7.5 months. Following progression, the molecular tumor board recommended a combination therapy approach comprising pazopanib, crizotinib, and palbociclib to target all of the changed pathways at the same time. Pazopanib was chosen to specifically target the FGFR2 alteration, while crizotinib was selected due to its potential synthetic lethality with the CDH1 alteration. In addition, the CDK4/6 inhibitor palbociclib was administered to address the CDKN2A/B alterations. The patient exhibited a remarkable and sustained response to this innovative combination. This case not only underscores the potential of tyrosine kinase inhibitors, exemplified by pazopanib, as a viable alternative for patients without access to pan-FGFR inhibitors, but it also emphasizes their efficacy beyond commonly detected point mutations and rearrangements. Notably, the outstanding response to combination therapy, including crizotinib, in a patient with a CDH1 alteration, further substantiates the preclinical evidence of synthetic lethality between crizotinib and CDH1 alterations. To our knowledge, this represents the first clinical evidence demonstrating the efficacy of crizotinib in a patient with a CDH1 alteration. Through careful dosage adjustments and consideration of individualized genomic information, this case exemplifies the power of personalized medicine in achieving favorable treatment outcomes.

Recent Advances in Pathology of Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICCA) is a malignant epithelial neoplasm characterized by biliary differentiation within the liver. ICCA is molecularly heterogeneous and exhibits a broad spectrum of histopathological features. It is a highly aggressive carcinoma with high mortality and poor survival rates. ICCAs are classified into two main subtypes: the small-duct type and large-duct types. These two tumor types have different cell origins and clinicopathological features. ICCAs are characterized by numerous molecular alterations, including mutations in KRAS, TP53, IDH1/2, ARID1A, BAP1, BRAF, SAMD4, and EGFR, and FGFR2 fusion. Two main molecular subtypes-inflammation and proliferation-have been proposed. Recent advances in high-throughput assays using next-generation sequencing have improved our understanding of ICCA pathogenesis and molecular genetics. The diagnosis of ICCA poses a significant challenge for pathologists because of its varied morphologies and phenotypes. Accurate diagnosis of ICCA is essential for effective patient management and prognostic determination. This article provides an updated overview of ICCA pathology, focusing particularly on molecular features, histological subtypes, and diagnostic approaches.

ETV6::NTRK3 Fusion-Positive Wild-Type Gastrointestinal Stromal Tumor (GIST) with Abundant Lymphoid Infiltration (TILs and Tertiary Lymphoid Structures): A Report on a New Case with Therapeutic Implications and a Literature Review

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract, with proto-oncogene, receptor tyrosine kinase (c-kit), or PDGFRα mutations detected in around 85% of cases. GISTs without c-kit or platelet-derived growth factor receptor alpha (PDGFRα) mutations are considered wild-type (WT), and their diverse molecular alterations and biological behaviors remain uncertain. They are usually not sensitive to tyrosine kinase inhibitors (TKIs). Recently, some molecular alterations, including neurotrophic tyrosine receptor kinase (NTRK) fusions, have been reported in very few cases of WT GISTs. This novel finding opens the window for the use of tropomyosin receptor kinase (TRK) inhibitor therapy in these subtypes of GIST. Herein, we report a new case of NTRK-fused WT high-risk GIST in a female patient with a large pelvic mass (large dimension of 20 cm). The tumor was removed, and the histopathology displayed spindle-predominant morphology with focal epithelioid areas, myxoid stromal tissue, and notable lymphoid infiltration with tertiary lymphoid structures. Ten mitoses were quantified in 50 high-power fields without nuclear pleomorphism. DOG1 showed strong and diffuse positivity, and CD117 showed moderate positivity. Succinate dehydrogenase subunit B (SDHB) was retained, Pan-TRK was focal positive (nuclear pattern), and the proliferation index Ki-67 was 7%. Next-generation sequencing (NGS) detected an ETV6::NTRK3 fusion, and this finding was confirmed by fluorescence in situ hybridization (FISH), which showed NTRK3 rearrangement. In addition, an RB1 mutation was found by NGS. The follow-up CT scan revealed peritoneal nodules suggestive of peritoneal dissemination, and Entrectinib (a TRK inhibitor) was administered. After 3 months of follow-up, a new CT scan showed a complete response. Based on our results and the cases from the literature, GISTs with NTRK fusions are very uncommon so far; hence, further screening studies, including more WT GIST cases, may increase the possibility of finding additional cases. The present case may offer new insights into the potential introduction of TRK inhibitors as treatments for GISTs with NTRK fusions. Additionally, the presence of abundant lymphoid infiltration in the present case may prompt further research into immunotherapy as a possible additional therapeutic option.

The contribution of new methods in cytology for increasing sensitivity in the diagnosis of extrahepatic bile duct lesions

The aim of this review is to provide a comprehensive analysis of the existing literature pertaining to cytology of extrahepatic bile ducts. A search using the keywords "biliary brush cytology" was conducted in the PubMed database, with a focus on recent articles. The inclusion criteria primarily encompassed publications addressing problematic biliary stenosis. Emphasis was placed on identifying articles that explored innovative or less-utilized examination techniques aimed at enhancing the sensitivity of cytological examination. This review presents a comprehensive overview of the various types of materials used in sampling and the corresponding sampling methods. Additionally, it explores cytological and cytogenetic techniques, such as fluorescence in situ hybridization (FISH) and genetic methods (miRNA, NGS, cfDNA). These techniques possess the potential to improve the accuracy of diagnosing bile duct tumors, although their sensitivity varies. Furthermore, their utilization can facilitate early therapy, which plays a crucial role in patient prognosis. Each examination is always dependent on the quality and quantity of material delivered. A higher sensitivity of these examinations can be achieved by combining biliary cytology and other complementary methods.

Don't Judge a Book by Its Cover: The Role of Statins in Liver Cancer

Statins, which are inhibitors of 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase, are an effective pharmacological tool for lowering blood cholesterol levels. This property makes statins one of the most popular drugs used primarily to prevent cardiovascular diseases, where hyperlipidemia is a significant risk factor that increases mortality. Nevertheless, studies conducted mainly in the last decade have shown that statins might prevent and treat liver cancer, one of the leading causes of cancer-related mortality worldwide. This narrative review summarizes the scientific achievements to date regarding the role of statins in liver tumors. Molecular biology tools have revealed that cell growth and proliferation can be inhibited by statins, which further inhibit angiogenesis. Clinical studies, supported by meta-analysis, confirm that statins are highly effective in preventing and treating hepatocellular carcinoma and cholangiocarcinoma. However, this effect may depend on the statin's type and dose, and more clinical trials are required to evaluate clinical effects. Moreover, their potential hepatotoxicity is a significant caveat for using statins in clinical practice. Nevertheless, this group of drugs, initially developed to prevent cardiovascular diseases, is now a key candidate in hepato-oncology patient management. The description of new drug-statin-like structures, e.g., with low toxicity to liver cells, may bring another clinically significant improvement to current cancer therapies.

A Novel Mouse Model of Intrahepatic Cholangiocarcinoma Induced by Azoxymethane

Cholangiocarcinoma is the second most common primary cancer of the liver and has a poor prognosis. Various animal models, including carcinogen-induced and genetically engineered rodent models, have been established to clarify the mechanisms underlying cholangiocarcinoma development. In the present study, we developed a novel mouse model of malignant lesions in the biliary ducts induced by the administration of the carcinogen azoxymethane to obese C57BLKS/J-db/db mice. A histopathological analysis revealed that the biliary tract lesions in the liver appeared to be an intrahepatic cholangiocarcinoma with higher tumor incidence, shorter experimental duration, and a markedly increased incidence in obese mice. Molecular markers analyzed using a microarray and a qPCR indicated that the cancerous lesions originated from the cholangiocytes and developed in the inflamed livers. These findings indicated that this is a novel mouse model of intrahepatic cholangiocarcinoma in the context of steatohepatitis. This model can be used to provide a better understanding of the pathogenic mechanisms of cholangiocarcinoma and to develop novel therapeutic strategies for this malignancy.

Past, present, and future of FGFR inhibitors in cholangiocarcinoma: from biological mechanisms to clinical applications

INTRODUCTION

Biliary tract carcinoma (BTC) is a heterogenous group of aggressive hepatic malignancies, second to hepatocellular carcinoma per prevalence. Despite clinical research advancement, the overall 5-year survival rate is just above 2%. With the identification of somatic core mutations in half of cholangiocarcinomas. In the intrahepatic subtype (iCCA), it is possible to target mutational pathways of pharmacological interest.

AREAS COVERED

Major attention has been drawn to fibroblast growth factor receptor (FGFR), especially the type 2 (FGFR2), found mutated in 10-15% of iCCAs. FGFR2 fusions became the target of novel tyrosine-kinase inhibitors investigated in clinical studies, showing promising results so as to gain regulatory approval by American and European committees in recent years. Such drugs demonstrated a better impact on the quality of life compared to standard chemotherapy; however, side effects including hyperphosphatemia, gastrointestinal, eye, and nail disorders are common although mostly manageable.

EXPERT OPINION

As FGFR inhibitors may soon become the new alternative to standard chemotherapy in FGFR-mutated cholangiocarcinoma, accurate molecular testing and monitoring of acquired resistance mechanisms will be essential. The possible application of FGFR inhibitors in first-line treatment, as well as in combination with current standard treatments, remains the next step to be taken.

Unraveling the Significance of EPH/Ephrin Signaling in Liver Cancer: Insights into Tumor Progression and Therapeutic Implications

Liver cancer is a complex and challenging disease with limited treatment options and dismal prognosis. Understanding the underlying molecular mechanisms driving liver cancer progression and metastasis is crucial for developing effective therapeutic strategies. The EPH/ephrin system, which comprises a family of cell surface receptors and their corresponding ligands, has been implicated in the pathogenesis of HCC. This review paper aims to provide an overview of the current understanding of the role of the EPH/ephrin system in HCC. Specifically, we discuss the dysregulation of EPH/ephrin signaling in HCC and its impact on various cellular processes, including cell proliferation, migration, and invasion. Overall, the EPH/ephrin signaling system emerges as a compelling and multifaceted player in liver cancer biology. Elucidating its precise mechanisms and understanding its implications in disease progression and therapeutic responses may pave the way for novel targeted therapies and personalized treatment approaches for liver cancer patients. Further research is warranted to unravel the full potential of the EPH/ephrin system in liver cancer and its clinical translation.

The Role of TLR4 in the Immunotherapy of Hepatocellular Carcinoma: Can We Teach an Old Dog New Tricks?

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and is a leading cause of cancer-related death worldwide. Immunotherapy has emerged as the mainstay treatment option for unresectable HCC. Toll-like receptor 4 (TLR4) plays a crucial role in the innate immune response by recognizing and responding primarily to bacterial lipopolysaccharides. In addition to its role in the innate immune system, TLR4 has also been implicated in adaptive immunity, including specific anti-tumor immune responses. In particular, the TLR4 signaling pathway seems to be involved in the regulation of several cancer hallmarks, such as the continuous activation of cellular pathways that promote cell division and growth, the inhibition of programmed cell death, the promotion of several invasion and metastatic mechanisms, epithelial-to-mesenchymal transition, angiogenesis, drug resistance, and epigenetic modifications. Emerging evidence further suggests that TLR4 signaling holds promise as a potential immunotherapeutic target in HCC. The aim of this review was to explore the multilayer aspects of the TLR4 signaling pathway, regarding its role in liver diseases and HCC, as well as its potential utilization as an immunotherapy target for HCC.