Thorotrast-induced liver neoplasia: a collective review

Cholangiocarcinoma: Recent Advances in Molecular Pathobiology and Therapeutic Approaches

Cholangiocarcinomas (CCA) pose a complex challenge in oncology due to diverse etiologies, necessitating tailored therapeutic approaches. This review discusses the risk factors, molecular pathology, and current therapeutic options for CCA and explores the emerging strategies encompassing targeted therapies, immunotherapy, novel compounds from natural sources, and modulation of gut microbiota. CCA are driven by an intricate landscape of genetic mutations, epigenetic dysregulation, and post-transcriptional modification, which differs based on geography (e.g., for liver fluke versus non-liver fluke-driven CCA) and exposure to environmental carcinogens (e.g., exposure to aristolochic acid). Liquid biopsy, including circulating cell-free DNA, is a potential diagnostic tool for CCA, which warrants further investigations. Currently, surgical resection is the primary curative treatment for CCA despite the technical challenges. Adjuvant chemotherapy, including cisplatin and gemcitabine, is standard for advanced, unresectable, or recurrent CCA. Second-line therapy options, such as FOLFOX (oxaliplatin and 5-FU), and the significance of radiation therapy in adjuvant, neoadjuvant, and palliative settings are also discussed. This review underscores the need for personalized therapies and demonstrates the shift towards precision medicine in CCA treatment. The development of targeted therapies, including FDA-approved drugs inhibiting FGFR2 gene fusions and IDH1 mutations, is of major research focus. Investigations into immune checkpoint inhibitors have also revealed potential clinical benefits, although improvements in survival remain elusive, especially across patient demographics. Novel compounds from natural sources exhibit anti-CCA activity, while microbiota dysbiosis emerges as a potential contributor to CCA progression, necessitating further exploration of their direct impact and mechanisms through in-depth research and clinical studies. In the future, extensive translational research efforts are imperative to bridge existing gaps and optimize therapeutic strategies to improve therapeutic outcomes for this complex malignancy.

Role of calcium ion channels and cytoskeletal proteins in Thorium-232 induced toxicity in normal human liver cells (WRL 68) and its validation in swiss mice

Hepatic disorders reported in humans exposed to Thorium-232 (Th-232) rationalizes the present study investigating the toxicological response of normal human liver cells (WRL 68) and its validation in Swiss mice. Cell count analysis of WRL 68 cells-treated with Th-nitrate (1-200 μM) estimated IC50 of ∼24 μM (at 24 h) and 35 μM (at 48 h). Analysis of cell viability (trypan blue assay) showed the IC50 of ∼172 μM. Phase contrast bright-field microscopy revealed Th-induced morphological changes and cell-released microvesicle-like structures in extracellular space. Th-estimation by ICP-MS (Inductively-coupled plasma mass-spectrometry) showed uptake of Th by cells as a function of concentration and incubation time. Employing DTPA as a chelating agent in cell harvesting solution, cell-internalized/strongly-bound Th was estimated to be ∼42% of total incubated Th. Th-uptake studies in the presence of ion-channel specific inhibitors (e.g. nifedipine, thapsigargin) revealed the role of plasma membrane calcium channels and cytoplasmic calcium in modulating the Th-uptake. Transmission electron microscopy of Th-treated cells showed cell-derived extracellular vesicles, alterations in the shape and size of nucleus and mitochondria as well as cytoplasmic inclusions. The order of Th accumulation in various sub-cellular protein fractions was found to be as cytoskeleton (43%) > cytoplasmic (15%) > chromatin (7%) > nuclear (5%) & membrane (5%). Immunofluorescence analysis of WRL 68 cells showed that Th significantly altered the expression of cytoskeleton proteins (F-actin and keratin), which was further validated in liver tissues of Swiss mice administered with Th-232. Findings herein highlight the role of calcium channels and cytoskeleton in Th-induced toxicity. Keywords: Thorium toxicity; Liver cells; Calcium channels; Sub-cellular targets, Cytoskeleton; Swiss Mice.

Mechanism of thorium-nitrate and thorium-dioxide induced cytotoxicity in normal human lung epithelial cells (WI26): Role of oxidative stress, HSPs and DNA damage

Inhalation represents the most prevalent route of exposure with Thorium-232 compounds (Th-nitrate/Th-dioxide)/Th-containing dust in real occupational scenario. The present study investigated the mechanism of Th response in normal human alveolar epithelial cells (WI26), exposed to Th-nitrate or colloidal Th-dioxide (1-100 μg/ml, 24-72 h). Assessment in terms of changes in cell morphology, cell proliferation (cell count), plasma membrane integrity (lactate dehydrogenase leakage) and mitochondrial metabolic activity (MTT reduction) showed that Th-dioxide was quantitatively more deleterious than Th-nitrate to WI26 cells. TEM and immunofluorescence analysis suggested that Th-dioxide followed a clathrin/caveolin-mediated endocytosis, however, membrane perforation/non-endocytosis seemed to be the mode of Th internalization in cells exposed to Th-nitrate. Th-estimation by ICP-MS showed significantly higher uptake of Th in cells treated with Th-dioxide than with Th-nitrate at a given concentration. Both Th-dioxide and nitrate were found to increase the level of reactive oxygen species, which seemed to be responsible for lipid peroxidation, alteration in mitochondrial membrane potential and DNA-damage. Amongst HSPs, the protein levels of HSP70 and HSP90 were affected differentially by Th-nitrate/dioxide. Specific inhibitors of ATM (KU55933) or HSP90 (17AAG) were found to increase the Th- cytotoxicity suggesting prosurvival role of these signaling molecules in rescuing the cells from Th-toxicity.

All for one, though not one for all: team players in normal tissue radiobiology

PURPOSE

As part of the special issue on 'Women in Science', this review offers a perspective on past and ongoing work in the field of normal (non-cancer) tissue radiation biology, highlighting the work of many of the leading contributors to this field of research. We discuss some of the hypotheses that have guided investigations, with a focus on some of the critical organs considered dose-limiting with respect to radiation therapy, and speculate on where the field needs to go in the future.

CONCLUSIONS

The scope of work that makes up normal tissue radiation biology has and continues to play a pivotal role in the radiation sciences, ensuring the most effective application of radiation in imaging and therapy, as well as contributing to radiation protection efforts. However, despite the proven historical value of preclinical findings, recent decades have seen clinical practice move ahead with altered fractionation scheduling based on empirical observations, with little to no (or even negative) supporting scientific data. Given our current appreciation of the complexity of normal tissue radiation responses and their temporal variability, with tissue- and/or organ-specific mechanisms that include intra-, inter- and extracellular messaging, as well as contributions from systemic compartments, such as the immune system, the need to maintain a positive therapeutic ratio has never been more urgent. Importantly, mitigation and treatment strategies, whether for the clinic, emergency use following accidental or deliberate releases, or reducing occupational risk, will likely require multi-targeted approaches that involve both local and systemic intervention. From our personal perspective as five 'Women in Science', we would like to acknowledge and applaud the role that many female scientists have played in this field. We stand on the shoulders of those who have gone before, some of whom are fellow contributors to this special issue.

"Turn-on" fluorescent sensor for Th4+ in aqueous media based on a combination of PET-AIE effect

Previously reported fluorescent sensors for Th⁴⁺ experienced emission quenching or generated false positive signal upon aggregate formation in aqueous media. Herein, a simple and novel thorium sensor (CDB-BA) based on cyanodistyrene structure was designed and synthesized, which integrated the highly emitting characteristic of AIE effect and off-on response of PET modulation for the first time to construct the "turn-on" fluorescent probe for Th⁴⁺. Besides excellent selectivity, CDB-BA exhibited remarkable fluorescent enhancement which was linearly related to the concentration of Th⁴⁺ in the range of 0.25-8 μM. The detection limit was attained 0.074 μM, which was lower than that of most previously reported sensors. The mechanism of tris-chelate complex of CDB-BA with Th⁴⁺ was confirmed by mass spectra, IR spectra and DFT calculation. The excellent Th⁴⁺ sensing ability of CDB-BA was successfully applied to detecting Th⁴⁺ on TLC plates, in real water samples and living-cell imaging. This work suggested that the combination of AIE and PET photophysical mechanism could offer the merits of minimized background and enhanced signal fidelity to develop novel "turn-on" fluorescent probe in complicated aqueous environment and biological research.

Impact of diseased liver parenchyma on perioperative outcome among patients with hepatocellular carcinoma undergoing hepatectomy: Experience from a developing country

INTRODUCTION

Limited data can be found about surgical outcome of patients with hepatocellular carcinoma (HCC) arising in non-diseased liver. The study aim was to compare short- and long-term outcomes among HCC patients with normal and diseased liver parenchyma, undergoing potentially curative liver resection in a developing country.

MATERIALS AND METHODS

From November 2001 until January 2017, 228 patients with HCC underwent curative-intent hepatectomy at the University Clinic for Digestive Surgery. From that number, 190 patients were eligible for analysis. Diseased liver (DL) was present in 112 patients while 78 patients had HCC in non-diseased liver (NDL).

RESULTS

Median age, sex, ASA score, the presence of extrahepatic disease and lobar distribution of tumors were similar in both groups. The number of tumors was higher in DL group, while tumor diameter was higher in NDL group. Anatomic liver resection and major liver resections were performed more commonly in NDL than in DL group (66.7 vs 47.4%, p = 0.008; 33.3 vs. 15.2%, p = 0.003). Postoperative morbidity was significantly higher in DL group (p = 0.004). Overall survival was statistically longer in NDL group (p = 0.024). By univariate analysis potential prognostic factors for long-term survival were identified: presence of chronic HCV infection, presence of cirrhosis, Child-Pugh score B and operative time longer than 240 min. The last two were confirmed by multivariate analysis as independent negative prognostic factors for overall survival.

CONCLUSION

Liver resection in patients with HCC arising in non-diseased livers, despite of need for extended hepatectomies, provides favorable long-term prognosis.

Colonic Angiosarcoma Arising in Association with Amyloid Deposits

Angiosarcoma of the colon is rare, as is colonic amyloidosis. To our knowledge, there have been no reported cases of angiosarcoma arising in association with amyloid deposition. Herein, we described a case of 77-year-old man who presented with hematochezia, and a sigmoid mass was found on colonoscopy. Histologic examination of the resected specimen showed extensive nodular deposition of AL-lambda amyloid material in the colonic wall, as well as high-grade angiosarcoma which was closely intermingled with the amyloid deposits. While the occurrence of both colonic amyloidosis and angiosarcoma in this patient may represent pure coincidence, given the intimate association of the angiosarcoma and the amyloid deposition and the rarity of both of these lesions, we hypothesize that angiosarcoma could be secondary to amyloid deposition.

Somatic mutation signatures in primary liver tumors of workers exposed to ionizing radiation

Liver cancer is associated with genetic mutations caused by environmental exposures, including occupational exposure to alpha radiation emitted by plutonium. We used whole exome sequencing (WES) to characterize somatic mutations in 3 histologically distinct primary liver tumors (angiosarcoma of the liver (ASL), cholangiocarcinoma (CCA) and hepatocellular carcinoma (HCC)) from Mayak worker subjects occupationally exposed to ionizing radiation (IR) to investigate the contribution of IR to the mutational landscape of liver cancer. DNA sequence analysis revealed these tumors harbor an excess of deletions, with a deletions:substitutions ratio similar to that previously reported in radiation-associated tumors. These tumors were also enriched for clustered mutations, a signature of radiation exposure. Multiple tumors displayed similarities in abrogated gene pathways including actin cytoskeletal signaling and DNA double-strand break (DSB) repair. WES identified novel candidate driver genes in ASL involved in angiogenesis and PIK3CA/AKT/mTOR signaling. We confirmed known driver genes of CCA, and identified candidate driver genes involved in chromatin remodeling. In HCC tumors we validated known driver genes, and identified novel putative driver genes involved in Wnt/β-catenin signaling, chromatin remodeling, PIK3CA/AKT/mTOR signaling, and angiogenesis. This pilot study identifies several novel candidate driver mutations that are likely to be caused by IR exposure, and provides the first data on the mutational landscape of liver cancer after IR exposure.

Thorium decorporation efficacy of rationally-selected biocompatible compounds with relevance to human application

During civil, nuclear or defense activities, internal contamination of actinides in humans and mitigation of their toxic impacts are of serious concern. Considering the health hazards of thorium (Th) internalization, an attempt was made to examine the potential of ten rationally-selected compounds/formulations to decorporate Th ions from physiological systems. The Th-induced hemolysis assay with human erythrocytes revealed good potential of tiron, silibin (SLB), phytic acid (PA) and Liv.52^® (L52) for Th decorporation, in comparison to diethylenetriaminepentaacetic acid, an FDA-approved decorporation drug. This was further validated by decorporation experiments with relevant human cell models (erythrocytes and liver cells) and biological fluid (blood) under pre-/post-treatment conditions, using inductively coupled plasma mass spectrometry (ICP-MS) and transmission electron microscopy (TEM). Furthermore, density functional theory-based calculations and extended X-ray absorption fine structure (EXAFS) spectroscopy confirmed the formation of Th complex by these agents. Amongst the chosen biocompatible agents, tiron, SLB, PA and L52 hold promise to enhance Th decorporation for human application.

Case Report: Two Cases of Cholangiocarcinoma in Patients with Opisthorchis felineus Infection in Western Siberia, Russian Federation

Cholangiocarcinoma (CCA) is a cancer with high mortality owing to its aggressiveness and resistance to therapy. The liver flukes of the Opisthorchiidae family have been recognized as risk factors of CCA. Opisthorchis felineus infection occurs in Western Siberia, the biggest endemic area in the Russian Federation, and is associated with chronic inflammation of the bile ducts, which may be linked to severe hepatobiliary morbidity. We report two cases of confirmed CCA who had a chronic O. felineus infection. Both cases presented unspecific symptoms at the onset of the disease, a stage when severe pathological changes already had occurred. Both patients were living in endemic areas but did not receive any antihelminthic treatment. This report underlines the need for assessment of O. felineus infection as a causative factor of CCA. The results will provide further arguments for control of O. felineus in the Russian Federation.

Molecular Pathogenesis of Cholangiocarcinoma

BACKGROUND

Cholangiocarcinomas are a heterogeneous group of malignancies arising from a number of cells of origin along the biliary tree. Although most cases in Western countries are sporadic, large population-based studies have identified a number of risk factors. This review summarises the evidence behind reported risk factors and current understanding of the molecular pathogenesis of cholangiocarcinoma, with a focus on inflammation and cholestasis as the driving forces in cholangiocarcinoma development.

RISK FACTORS FOR CHOLANGIOCARCINOGENESIS

Cholestatic liver diseases (e.g. primary sclerosing cholangitis and fibropolycystic liver diseases), liver cirrhosis, and biliary stone disease all increase the risk of cholangiocarcinoma. Certain bacterial, viral or parasitic infections such as hepatitis B and C and liver flukes also increase cholangiocarcinoma risk. Other risk factors include inflammatory disorders (such as inflammatory bowel disease and chronic pancreatitis), toxins (e.g. alcohol and tobacco), metabolic conditions (diabetes, obesity and non-alcoholic fatty liver disease) and a number of genetic disorders.

MOLECULAR PATHOGENESIS OF CHOLANGIOCARCINOMA

Regardless of aetiology, most risk factors cause chronic inflammation or cholestasis. Chronic inflammation leads to increased exposure of cholangiocytes to the inflammatory mediators interleukin-6, Tumour Necrosis Factor-ɑ, Cyclo-oxygenase-2 and Wnt, resulting in progressive mutations in tumour suppressor genes, proto-oncogenes and DNA mismatch-repair genes. Accumulating bile acids from cholestasis lead to reduced pH, increased apoptosis and activation of ERK1/2, Akt and NF-κB pathways that encourage cell proliferation, migration and survival. Other mediators upregulated in cholangiocarcinoma include Transforming Growth Factor-β, Vascular Endothelial Growth Factor, Hepatocyte Growth Factor and several microRNAs. Increased expression of the cell surface receptor c-Met, the glucose transporter GLUT-1 and the sodium iodide symporter lead to tumour growth, angiogenesis and cell migration. Stromal changes are also observed, resulting in alterations to the extracellular matrix composition and recruitment of fibroblasts and macrophages that create a microenvironment promoting cell survival, invasion and metastasis.

CONCLUSION

Regardless of aetiology, most risk factors for cholangiocarcinoma cause chronic inflammation and/or cholestasis, leading to the activation of common intracellular pathways that result in reactive cell proliferation, genetic/epigenetic mutations and cholangiocarcinogenesis. An understanding of the molecular pathogenesis of cholangiocarcinoma is vital when developing new diagnostic biomarkers and targeted therapies for this disease.

Historical Perspective of Imaging Contrast Agents

Contrast agents were introduced early in the history of medical imaging. Iodine-based intravascular agents became the radiographic compounds of choice and refinements of their chemical structures led to the highly tolerated low-osmolarity agents in use today. Gadolinium became the most popular compound for MR imaging; however, recognition of nephrogenic systemic fibrosis and in vivo dechelation intensified research on their safety profile. Ultrasonography contrast media evolved from manual injections of air through agitated saline solutions to microbubbles with different gases. Research has concentrated on bubble stabilization and development of small but sufficiently echogenic particles.

Why Do Promising Therapies Stall in Development and How Can We Move Them Forward?

There are many reasons that molecules fail to progress to market and various principles of risk-benefit decisions that can help drive the molecule through development. This symposium included discussions on global strategies involved in pushing promising molecules to market, what to do when a molecule stalls in its progress to market, and options for rescuing the molecule and pushing it forward again. Innovative partnerships that bring stalled drugs back into clinical development were also addressed. A regulatory perspective on common reasons for a molecule to fail in its forward progress was presented. In addition, situations arise when a third-party advisory committee can provide input to help overcome issues identified by a regulatory agency. Using examples from the private and public domain, presentations centered on how to repurpose a molecule and when more science is needed.

Comprehensive analysis of transcriptome and metabolome analysis in Intrahepatic Cholangiocarcinoma and Hepatocellular Carcinoma

Intrahepatic cholangiocarcinoma (ICC) and hepatocellular carcinoma (HCC) are liver originated malignant tumors. Of the two, ICC has the worse prognosis because it has no reliable diagnostic markers and its carcinogenic mechanism is not fully understood. The aim of this study was to integrate metabolomics and transcriptomics datasets to identify variances if any in the carcinogenic mechanism of ICC and HCC. Ten ICC and 6 HCC who were resected surgically, were enrolled. miRNA and mRNA expression analysis were performed by microarray on ICC and HCC and their corresponding non-tumor tissues (ICC_NT and HCC_NT). Compound analysis was performed using capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS). Principle component analysis (PCA) revealed that among the four sample groups (ICC, ICC_NT, HCC, and HCC_NT) there were 14 compounds, 62 mRNAs and 17 miRNAs with two distinct patterns: tumor and non-tumor, and ICC and non-ICC. We accurately (84.38%) distinguished ICC by the distinct pattern of its compounds. Pathway analysis using transcriptome and metabolome showed that several pathways varied between tumor and non-tumor samples. Based on the results of the PCA, we believe that ICC and HCC have different carcinogenic mechanism therefore knowing the specific profile of genes and compounds can be useful in diagnosing ICC.

Morphological subclassification of intrahepatic cholangiocarcinoma: etiological, clinicopathological, and molecular features

On the basis of morphological features, we subclassified 189 intrahepatic cholangiocarcinomas into two subtypes: bile duct and cholangiolar. The cholangiolar type is composed of cuboidal to low columnar tumor cells that contain scanty cytoplasm. The bile duct type is composed of tall columnar tumor cells arranged in a large glandular pattern. In this study, 77 (41%) tumors were classified as the cholangiolar type and 112 (59%) tumors were classified as the bile duct type. The cholangiolar-type intrahepatic cholangiocarcinoma was more frequently associated with viral hepatitis, whereas all but one intrahepatic cholangiocarcinoma associated with intrahepatic lithiasis were classified as the bile duct type. Biliary intraepithelial neoplasm or intraductal papillary neoplasm of the bile duct could be identified in 50 bile duct-type intrahepatic cholangiocarcinomas (45%), but in only 3 cholangiolar-type intrahepatic cholangiocarcinomas (4%). Cholangiolar-type intrahepatic cholangiocarcinomas frequently expressed N-cadherin, whereas bile duct intrahepatic cholangiocarcinomas were more likely to express S100P, Trefoil factor 1, and anterior gradient 2. KRAS is mutated in 23 of 98 (23%) bile duct-type intrahepatic cholangiocarcinomas and in only 1 of 76 (1%) cholangiolar-type intrahepatic cholangiocarcinomas. Cholangiolar-type intrahepatic cholangiocarcinomas had a higher frequency of IDH1 or 2 mutations than did the bile duct-type intrahepatic cholangiocarcinomas. The molecular features of the bile duct-type intrahepatic cholangiocarcinoma were similar to those of hilar cholangiocarcinoma. Patients with the cholangiolar-type intrahepatic cholangiocarcinoma had higher 5-year survival rates than those of patients with the bile duct-type intrahepatic cholangiocarcinoma. Our results indicated that intrahepatic cholangiocarcinoma was a heterogeneous tumor. Subclassification of intrahepatic cholangiocarcinomas based on cholangiocytic differentiation divides them into two groups with different etiologies, clinical manifestations, and molecular pathogeneses.

Key roles for MYC, KIT and RET signaling in secondary angiosarcomas

Background:

Angiosarcomas may develop as primary tumours of unknown cause or as secondary tumours, most commonly following radiotherapy to the involved field. The different causative agents may be linked to alternate tumorigenesis, which led us to investigate the genetic profiles of morphologically indistinguishable primary and secondary angiosarcomas.

Methods:

Whole-genome (18k) c-DNA-mediated annealing, selection, extension and ligation analysis was used to genetically profile 26 primary and 29 secondary angiosarcomas. Key findings were thereafter validated using RT–qPCR, immunohistochemistry and validation of the gene signature to an external data set.

Results:

In total, 103 genes were significantly deregulated between primary and secondary angiosarcomas. Secondary angiosarcomas showed upregulation of MYC, KIT and RET and downregulation of CDKN2C. Functional annotation analysis identified multiple target genes in the receptor protein tyrosine kinase pathway. The results were validated using RT–qPCR and immunohistochemistry. Further, the gene signature was applied to an external data set and, herein, distinguished primary from secondary angiosarcomas.

Conclusions:

Upregulation of MYC, KIT and RET and downregulation of CDKN2C characterise secondary angiosarcoma, which implies possibilities for diagnostic application and a mechanistic basis for therapeutic evaluation of RET-kinase-inhibitors in these highly aggressive tumours.

Challenges in the treatment of angiosarcoma: a single institution experience

BACKGROUND

Angiosarcomas are rare tumors that carry poor prognosis. Because of insidious growth rate, the diagnosis is often difficult and delayed.

METHODS

Between 1990 and 2011, 72 (41 female, 31 male) patients were treated at our institution. Pathologic confirmation was obtained and multiple prognostic factors were evaluated for survival.

RESULTS

Forty-four cases were sporadic and 28 cases were secondary. In the sporadic group, 16 (36%) patients had increased sun exposure, while in the secondary group, the majority (n = 23, 82%) of patients had prior exposure to radiation. The latent period between radiation exposure and diagnosis was predictive of survival (P = .037). Presentation was delayed by more than 3 months in 41% of patients. The majority of men developed head and neck angiosarcomas (n = 15, 48.5%), while women developed breast angiosarcomas (n = 21, 51%). Median survival was prolonged in patients treated initially with surgery.

CONCLUSIONS

A delay in the diagnosis of angiosarcoma can affect survival. Clinical suspicion and prompt diagnosis are essential for successful multimodal therapy. Initial surgical resection with adjuvant chemotherapy provides survival advantage.

Malignant vascular tumors--an update

Although benign hemangiomas are among the most common diagnoses amid connective tissue tumors, sarcomas showing endothelial differentiation (ie, angiosarcoma and epithelioid hemangioendothelioma) represent under 1% of all sarcoma diagnoses, and thus it is likely that fewer than 500 people in the United States are affected each year. Differential diagnosis of malignant vascular tumors can be often quite challenging, either at the low end of the spectrum, distinguishing an epithelioid hemangioendothelioma from an epithelioid hemangioma, or at the high-grade end of the spectrum, between an angiosarcoma and a malignant epithelioid hemangioendothelioma. Within this differential diagnosis both clinico-radiological features (ie, size and multifocality) and immunohistochemical markers (ie, expression of endothelial markers) are often similar and cannot distinguish between benign and malignant vascular lesions. Molecular ancillary tests have long been needed for a more objective diagnosis and classification of malignant vascular tumors, particularly within the epithelioid phenotype. As significant advances have been recently made in understanding the genetic signatures of vascular tumors, this review will take the opportunity to provide a detailed update on these findings. Specifically, this article will focus on the following aspects: (1) pathological and molecular features of epithelioid hemangioendothelioma, including the more common WWTR1-CAMTA1 fusion, as well as the recently described YAP1-TFE3 fusion, identified in a morphological variant of epithelioid hemangioendothelioma; (2) discuss the heterogeneity of angiosarcoma clinical, morphological and genetic spectrum, with particular emphasis of MYC and FLT4 gene amplification in radiation-induced angiosarcoma; and (3) provide a practical guide in the differential diagnosis of epithelioid vascular tumors using molecular testing.

Angiosarcomas and other sarcomas of endothelial origin

Although benign hemangiomas are among the most common diagnoses among connective tissue tumors, angiosarcomas and other sarcomas arising from blood vessels are rare, even among sarcomas. Because endothelial tumors have unique embryonal derivation compared with other sarcomas, it is not surprising they have unique characteristics. Herein are reviewed some of these unique characteristics and therapeutic options for patients with some of these diagnoses, highlighting the potential of new agents for these tumors, which will in all likelihood also impact treatment on more common cancers.

Comprehensive clinical and pathological analysis of three rare vascular tumor cases

The histological boundary between benign and malignant vascular tumors is not clear. Thus, the discrepancies between clinical judgement and pathological diagnosis often lead to a difficult clinical decision, and may result in misdiagnosis. In order to develop more effective treatment methods, the clinical and pathological data concerning rare vascular tumors should be comprehensively analyzed. To clarify the important roles of clinical and pathological analyses in vascular tumors, three rare vascular tumor cases that we encountered in clinical practice are analyzed and reported in detail.

Inorganic nanoparticles based contrast agents for X-ray computed tomography

Nanomaterials have gained considerable attention and interest in the development of new and efficient molecular probes for medical diagnosis and imaging. Heavy metal nanoparticles as such are excellent absorber of X-rays and can offer excellent improvement in medical diagnosis and X-ray imaging. Substantial progress has been made in the synthesis protocol and characterization studies of these materials but a major challenge still lies in the toxicological studies, which are rather incomplete. The worst known cases were those associated with Thorotrast (suspension of ThO(2) nanoparticles) which resulted in many deaths over years. Properly protected nanomaterials conjugated or coated with biocompatible materials can be used for the fabrication of various functional systems with multimodality, targeting properties, reduced toxicity and proper removal from the body. This review aims mainly to provide the advances in the development of inorganic nanoparticle based X-ray contrasting agents with an overview of methods of their preparation, functionalization and applications in medical diagnosis.

Mode of action associated with development of hemangiosarcoma in mice given pregabalin and assessment of human relevance

Pregabalin increased the incidence of hemangiosarcomas in carcinogenicity studies of 2-year mice but was not tumorigenic in rats. Serum bicarbonate increased within 24 h of pregabalin administration in mice and rats. Rats compensated appropriately, but mice developed metabolic alkalosis and increased blood pH. Local tissue hypoxia and increased endothelial cell proliferation were also confirmed in mice alone. The combination of hypoxia and sustained increases in endothelial cell proliferation, angiogenic growth factors, dysregulated erythropoiesis, and macrophage activation is proposed as the key event in the mode of action (MOA) for hemangiosarcoma formation. Hemangiosarcomas occur spontaneously in untreated control mice but occur only rarely in humans. The International Programme on Chemical Safety and International Life Sciences Institute developed a Human Relevance Framework (HRF) analysis whereby presence or absence of key events can be used to assess human relevance. The HRF combines the MOA with an assessment of biologic plausibility in humans to assess human relevance. This manuscript compares the proposed MOA with Hill criteria, a component of the HRF, for strength, consistency, specificity, temporality, and dose response, with an assessment of key biomarkers in humans, species differences in response to disease conditions, and spontaneous incidence of hemangiosarcoma to evaluate human relevance. Lack of key biomarker events in the MOA in rats, monkeys, and humans supports a species-specific process and demonstrates that the tumor findings in mice are not relevant to humans at the clinical dose of pregabalin. Based on this collective dataset, clinical use of pregabalin would not pose an increased risk for hemangiosarcoma to humans.

Hemangiosarcoma in mice administered pregabalin: analysis of genotoxicity, tumor incidence, and tumor genetics

Pregabalin, (S)-3-(aminomethyl)-5-methylhexanoic acid, binds with high affinity to the α(2)δ subunit of voltage-gated calcium channels and exerts analgesic, anxiolytic, and antiseizure activities. Two-year carcinogenicity studies were completed in B6C3F1 and CD-1 mice and two separate studies in Wistar rats. Doses in mice were 200, 1000, and 5000 mg/kg/day, with systemic exposures (AUC(0-24 h)) up to 31 times the mean exposure in humans, given the maximum recommended clinical dose. In rats, doses were 50, 150, and 450 mg/kg/day in males and 100, 300, and 900 mg/kg/day in females; systemic exposures up to 24 times were achieved in clinical trials. In both strains of mice, pregabalin treatment was associated with an increased incidence of hemangiosarcoma primarily in liver, spleen, and bone marrow. The incidence of hemangiosarcoma was higher in B6C3F1 mice than in CD-1 mice, consistent with its spontaneous incidence. Pregabalin did not increase the incidence of any other tumor type in rats and was not genotoxic, based on an extensive battery of in vivo and in vitro tests in bacterial and mammalian systems. Thus, pregabalin is a single-species, single tumor-type, nongenotoxic mouse carcinogen. Hemangiosarcomas occurring in mice treated with pregabalin were genotypically distinct from hemangiosarcomas induced by genotoxic carcinogens in humans with respect to ras and p53 mutation patterns and were similar to spontaneous tumors. Furthermore, there was a strong association between pregabalin treatment and bone marrow changes in these studies in mice, suggesting a possible link between the effects observed in bone marrow and the increase in tumor incidence in pregabalin-treated mice.

Risk factors for cholangiocarcinoma

Cholangiocarcinoma (CC) is the second most common primary hepatic malignancy after hepatocellular cancer. CC accounts for approximately 10%-25% of all hepatobiliary malignancies. There are considerable geographic and demographic variations in the incidence of CC. There are several established risk factors for CC, including parasitic infections, primary sclerosing cholangitis, biliary-duct cysts, hepatolithiasis, and toxins. Other less-established potential risk factors include inflammatory bowel disease, hepatitis C virus, hepatitis B virus, cirrhosis, diabetes, obesity, alcohol drinking, tobacco smoking, and host genetic polymorphisms. In studies where the distinction between intra- and extrahepatic CC was used, some potential risk factors seem to have a differential effect on CC, depending on the site. Therefore, the consistent use of a more refined classification would allow a better understanding of risk factors for CC.

Viral hepatitis is associated with intrahepatic cholangiocarcinoma with cholangiolar differentiation and N-cadherin expression

Viral hepatitis-associated intrahepatic cholangiocarcinoma is thought to have common disease processes with hepatocellular carcinoma, but until now the histomorphological and genetic features of viral hepatitis-associated intrahepatic cholangiocarcinoma is still unknown. From 2000 to 2010, 170 patients with intrahepatic cholangiocarcinoma who received detailed pathological assessment and regular follow-up at the National Taiwan University Hospital were selected for this study. Of 170 patients, 69 (41%) were positive for hepatitis B and/or C virus. These patients were younger, were more frequently male, and had elevated serum α-fetoprotein levels as compared with seronegative intrahepatic cholangiocarcinoma patients. Grossly these tumors were mostly of the mass-forming type, and histologically, cholangiolar differentiation was more frequently seen. We identified N-cadherin as an immunohistochemical marker strongly associated with hepatitis virus infection. The prevalence of viral hepatitis in patients with N-cadherin-positive intrahepatic cholangiocarcinoma was 75%, and that in N-cadherin-negative patients was only 37%. N-cadherin-positive patients were younger, had elevated α-fetoprotein, and had no hepatolithiasis. All N-cadherin-positive intrahepatic cholangiocarcinomas were of the mass-forming type. N-cadherin positivity was strongly associated with cholangiolar morphology and lack of carcinoembryonic antigen and MUC2 expression, whereas K-RAS mutations were less frequent. Our results indicate that a subgroup of intrahepatic cholangiocarcinoma characterized by cholangiolar differentiation and N-cadherin expression is strongly associated with viral hepatitis.

Hepatocellular carcinoma in non-cirrhotic liver: a reappraisal

Although not frequently, hepatocellular carcinoma (HCC) can ensue in a non-cirrhotic liver. As compared to cirrhotic HCC, this kind of tumour has some peculiarities, such as: (a) a lower male preponderance and a bimodal age distribution; (b) a lower prevalence of the three main risk factors (hepatitis B and C virus infections and alcohol abuse), with an increased prevalence of other etiologic factors, such as exposure to genotoxic substances and sex hormones, inherited diseases, genetic mutations; (c) a more advanced tumour stage at the time of diagnosis, as it is usually detected due to the occurrence of cancer-related symptoms, outside any scheduled surveillance program; (d) a much higher amenability to hepatic resection, due to the low risk of liver failure even after extended parenchymal mutilation; (e) overall and disease-free survivals after resection of non-advanced tumours (meeting the Milano criteria) comparable to that obtained with liver transplantation in cirrhotic patients carrying an early tumour; (f) overall survival strictly dependent on tumour burden (and its recurrence) and barely influenced by liver function.

Cholangiocarcinoma: update and future perspectives

Cholangiocarcinoma is commonly considered a rare cancer. However, if we consider the hepato-biliary system a single entity, cancers of the gallbladder, intra-hepatic and extra-hepatic biliary tree altogether represent approximately 30% of the total with incidence rates close to that of hepatocellular carcinoma, which is the third most common cause of cancer-related death worldwide. In addition, cholangiocarcinoma is characterized by a very poor prognosis and virtually no response to chemotherapeutics; radical surgery, the only effective treatment, is not frequently applicable because late diagnosis. Biomarkers for screening programs and for follow-up of categories at risk are under investigation, however, currently none of the proposed markers has reached clinical application. For all these considerations, cancers of the biliary tree system should merit much more scientific attention also because a progressive increase in incidence and mortality for these cancers has been reported worldwide. This manuscript deals with the most recent advances in the epidemiology, biology and clinical presentation of cholangiocarcinoma.

Advances in diagnosis, treatment and palliation of cholangiocarcinoma: 1990-2009

Several advances in diagnosis, treatment and palliation of cholangiocarcinoma (CC) have occurred in the last decades. A multidisciplinary approach to this disease is therefore recommended. CC is a relatively rare tumor and the main risk factors are: chronic inflammation, genetic predisposition and congenital abnormalities of the biliary tree. While the incidence of intra-hepatic CC is increasing, the incidence of extra-hepatic CC is trending down. The only curative treatment for CC is surgical resection with negative margins. Liver transplantation has been proposed only for selected patients with hilar CC that cannot be resected who have no metastatic disease after a period of neoadjuvant chemo-radiation therapy. Magnetic resonance imaging/magnetic resonance cholangiopancreatography, positron emission tomography scan, endoscopic ultrasound and computed tomography scans are the most frequently used modalities for diagnosis and tumor staging. Adjuvant therapy, palliative chemotherapy and radiotherapy have been relatively ineffective for inoperable CC. For most of these patients biliary stenting provides effective palliation. Photodynamic therapy is an emerging palliative treatment that seems to provide pain relief, improve biliary patency and increase survival. The clinical utility of other emerging therapies such as transarterial chemoembolization, hepatic arterial chemoinfusion and high intensity intraductal ultrasound needs further study.

[Risks factors for pediatric malignant liver tumors]

OBJECTIVE

Pediatric Hepatic Malignancies (PHMs) are the result of the interaction between constitutional and environmental risk factors (RFs). We review the evidence on the main RFs associated to PHMs.

METHOD

Systematic review of the literature published in the last 25 years on Medline, Embase, Cancerlit, Lilacs and SciElo using the following key words: "etiology/risk factor/epidemiology" and "malignant liver tumors/hepatic cancer" or "hepatoblastoma/hepatocarcionoma".

RESULTS

PHMs account for 1 % of all pediatric malignancies. The main types, hepatoblastoma (HB) and hepatocarcionma (HCC) make up 98-99 % of PHM. The main constitutional RFs are: a) Beckwith-Wiedemann (BW) syndrome; b) isolated hemihyperplasia syndrome (IHS); c) adenomatous polyps of the colon; d) hemochromatosis; e) Hereditary Tyrosinemia Type 1; f) a -1-antitrypsin deficiency; g) porphyrias; h) cirrhosis; i) nonalcoholic steatosis; and j) primary sclerosing cholangitis. The main environmental RFs are: a) hepatitis B virus (HBV) and C virus (HCV); b) B1 aflatoxin (B1AF); c) ionizing radiation; d) alcohol; e) hormonal treatments; f) occupational exposure to pesticides, solvents, vinyl chloride and metals; g) smoking; h) arsenic; i) prematury and very low birth weight; and j) trematodes.

CONCLUSIONS

The clinical, analytical and ultrasound screening facilitate the early diagnosis of HB in the previously mentioned genetic syndromes, particularly BW and IHS during the first years of life. HBV universal vaccination of newborns provides the biggest opportunity to prevent a substantial proportion of PHMs. Also systematic monitoring of HBV and HCV in blood, hemoderivates, donated organs and drug addicts, are very useful. Other effective measures are: the reduction/elimination of B(1)AF in food, zero alcohol intake during childhood and adolescence as well decreasing prenatal exposure to the tobacco, solvents, pesticides, vinyl chloride, metals, ionizing radiation and hormonal treatments.

Anaphylactoid and adverse reactions to radiocontrast agents

Over the past 75 years, radiocontrast agents have provided numerous diagnostic and therapeutic advances. The benefits of these agents must be weighed against the potential risks for each individual undergoing radiologic tests. This summary is intended to be a guide for the allergy and immunology specialist to direct him or her to the current literature regarding adverse reactions to traditional and less commonly used radiologic contrast agents.