Hepatocellular Carcinoma Related to Schistosoma mansoni Infection: Case Series and Literature Review

From the discovery of helminths to the discovery of their carcinogenic potential

Cancer involves a major aberration in the normal behaviour of cells, making them divide continuously, which interferes with the normal physiology of the body. The link between helminths and their cancer-inducing potential has been proposed in the last century. The exact pathway is still not clear but chronic inflammation in response to the deposited eggs, immune response against soluble egg antigens, and co-infection with a third party (a bacteria, a virus, or infection leading to a change in microbiome) seems to be the reasons for cancer induction. This review looks into the historical outlook on helminths along with their epidemiology, morphology, and life cycle. It then focuses on providing correlations between helminth infection and molecular mechanism of carcinogenesis by elaborating upon epidemiological, clinical, and surgical studies. While the cancer-inducing potential has been convincingly established only for a few helminths and studies point out towards possible cancer-inducing ability of the rest of the helminths elucidated in this work, however, more insights into the immunobiology of helminths as well as infected patients are required to conclusively comment upon this ability of the latter.

HEPATOSPLENIC SCHISTOSOMIASIS-ASSOCIATED CHRONIC PORTAL VEIN THROMBOSIS: RISK FACTOR FOR HEPATOCELLULAR CARCINOMA?

BACKGROUND

Hepatosplenic schistosomiasis is an endemic disease prevalent in tropical countries and is associated with a high incidence of portal vein thrombosis. Inflammatory changes caused by both parasitic infection and portal thrombosis can lead to the development of chronic liver disease with potential carcinogenesis.

AIMS

To assess the incidence of portal vein thrombosis and hepatocellular carcinoma in patients with schistosomiasis during long-term follow-up.

METHODS

A retrospective study was conducted involving patients with schistosomiasis followed up at our institution between 1990 and 2021.

RESULTS

A total of 126 patients with schistosomiasis were evaluated in the study. The mean follow-up time was 16 years (range 5-31). Of the total, 73 (57.9%) patients presented portal vein thrombosis during follow-up. Six (8.1%) of them were diagnosed with hepatocellular carcinoma, all with portal vein thrombosis diagnosed more than ten years before.

CONCLUSIONS

The incidence of hepatocellular carcinoma in patients with schistosomiasis and chronic portal vein thrombosis highlights the importance of a systematic long-term follow-up in this group of patients.

Liver Disease Outcomes after Sustained Virological Response in Patients with Chronic Hepatitis C Infection Treated with Generic Direct-Acting Antivirals

The introduction of generic direct-acting antivirals (DAAs) in Egypt is associated with a superior cure rate of hepatitis C virus (HCV) infection. However, the course of progressive liver damage and developing liver related complications in patients with sustained virologic response (SVR) remain unclear. This study was designed to examine the long-term outcomes of generic DAA-induced virological cure in a real-life cohort of HCV patients with or without comorbid schistosomiasis. We prospectively enrolled a cohort of 506 recently cured HCV patients (437 Child-Pugh class A [Child-A] and 69 Child-Pugh class B [Child-B]). All patients were clinically evaluated at different time points during a 2-year follow-up (November 2018 to February 2021). Over the course of treatment and follow-up, 77 (15.2%) patients (42 [9.6%] Child-A and 35 [50.7%] Child-B) experienced complications at different time points. The overall mortality rate was approximately 1/1,000 person-years. The incidence of hepatic insufficiency was approximately 5.5/1,000 person-years, and that of de novo hepatocellular carcinoma (HCC) was approximately 8.3/1,000 person-years. A sustained improvement in liver indices up to 2 years of follow-up was observed. In the Cox regression model, pretreatment decompensated cirrhosis predicted the occurrence of adverse liver events and HCC after therapy. In conclusion, in HCV patients with advanced cirrhosis or coexisting hepatic schistosomiasis, generic DAA-induced SVR remains robust with favorable clinical outcomes although the risk of hepatocarcinogenesis cannot be eliminated. Surveillance of patients with treated HCV infection is an important aspect of postcure care for early detection and management of liver disease-related adverse events.

Bacterial and Parasitic Pathogens as Risk Factors for Cancers in the Gastrointestinal Tract: A Review of Current Epidemiological Knowledge

The oncogenic potential of viral infections is well established and documented for many years already. However, the contribution of (commensal) bacteria and parasites to the development and progression of cancers has only recently gained momentum, resulting in a rapid growth of publications on the topic. Indeed, various bacteria and parasites have been suggested to play a role in the development of gastrointestinal cancer in particular. Therefore, an overview of the current epidemiological knowledge on the association between infections with bacteria and parasites and cancers of the gastrointestinal tract is needed. In this review, we summarized the methodological characteristics and main results of epidemiological studies investigating the association of 10 different bacteria (Bacteroides fragilis, Campylobacter spp., Clostridium spp., Enterococcus faecalis, Escherichia coli, Fusobacterium nucleatum, Porphyromonas gingivalis, non-typhoidal Salmonella, Salmonella Typhi, and Streptococcus spp.) and three parasites (Cryptosporidium spp., Schistosoma spp., and Strongyloides stercoralis) with gastrointestinal cancer. While the large body of studies based on microbiome sequencing provides valuable insights into the relative abundance of different bacterial taxa in cancer patients as compared to individuals with pre-malignant conditions or healthy controls, more research is needed to fulfill Koch's postulates, possibly making use of follow-up data, to assess the complex role of bacterial and parasitic infections in cancer epidemiology. Studies incorporating follow-up time between detection of the bacterium or parasite and cancer diagnosis remain valuable as these allow for estimation of cause-effect relationships.

Schistosoma mansoni infection and the occurrence, characteristics, and survival of patients with hepatocellular carcinoma: an observational study over a decade

Schistosoma mansoni infection (SMI) is suspected to be directly and indirectly involved in hepato-carcinogenesis. This study evaluated the association of a previous SMI with hepatocellular carcinoma (HCC) development, patients, tumor characteristics, treatment outcomes, and survival. This observational study included patients with HCC with and without previous SMI who presented to the multidisciplinary HCC clinic, Kasr-Alainy hospital (November 2009 to December 2019). It also included 313 patients with liver cirrhosis without HCC. Clinical and laboratory features of the patients (complete blood count, liver/renal functions , alpha-fetoprotein, and hepatitis B/C status), tumor characteristics (Triphasic CT and/or dynamic MRI), liver stiffness (transient elastography), HCC treatment outcome, and overall survival were studied. This study included 1446 patients with HCC; 688(47.6%) composed group-1, defined by patients having a history of SMI, and 758(52.4%) were in group-2 and without history of SMI. Male sex, smoking, diabetes mellitus, splenomegaly, deteriorated performance status, synthetic liver functions, and platelet count were significantly higher in group-1. The groups did not differ with regard to liver stiffness, tumor characteristics, or the occurrence of post-HCC treatment hepatic decompensation or recurrence. HCC treatment response was better in group-2. Group-1 showed lower sustained virological response to hepatitis C direct-acting antivirals (DAAs) compared with group-2 (60% versus 84.3%, respectively, P = 0.027). Prior SMI was associated with HCC (adjusted odds ratio = 1.589, 95% confidence interval = 1.187-2.127), and it was concluded that it increases the risk of HCC. In addition, it significantly affects the performance status, laboratory characteristics, response to DAAs, and overall survival.

Does Schistosoma Mansoni Facilitate Carcinogenesis?

Schistosomiasis is one of the most prominent parasite-induced infectious diseases, causing tremendous medical and socioeconomic problems. Current studies have reported on the spread of endemic regions and the fear of development of resistance against praziquantel, the only effective drug available. Among the Schistosoma species, only S. haematobium is classified as a Group 1 carcinogen (definitely cancerogenic to humans), causing squamous cell carcinoma of the bladder, whereas infection with S. mansoni is included in Group 3 of carcinogenic hazards to humans by the International Agency for Research on Cancer (IARC), indicating insufficient evidence to determine its carcinogenicity. Nevertheless, although S. mansoni has not been discussed as an organic carcinogen, the multiplicity of case reports, together with recent data from animal models and cell culture experiments, suggests that this parasite can predispose patients to or promote hepatic and colorectal cancer. In this review, we discuss the current data, with a focus on new developments regarding the association of S. mansoni infection with human cancer and the recently discovered biomolecular mechanisms by which S. mansoni may predispose patients to cancer development and carcinogenesis.

Imaging Spectrum of Granulomatous Diseases of the Abdomen and Pelvis

A granuloma is a compact organization of mature macrophages that forms because of persistent antigenic stimulation. At the microscopic level, granulomas can undergo various morphologic changes, ranging from necrosis to fibrosis, which along with other specialized immune cells define the appearance of the granulomatous process. Accordingly, the imaging features of granulomatous diseases vary and can overlap with those of other diseases, such as malignancy, and lead to surgical excisions and biopsy. However, given the heterogeneity of granulomas as a disease group, it is often hard to make a diagnosis on the basis of the histopathologic features of granulomatous diseases alone owing to overlapping microscopic features. Instead, a multidisciplinary approach is often helpful. Radiologists need to be familiar with the salient clinical manifestations and imaging findings of granulomatous diseases to generate an appropriate differential diagnosis. ^©RSNA, 2021.

Other types of diffuse liver disease: is there a way to do it?

There are a variety of less common diffuse liver diseases that can be asymptomatic or cause severe liver dysfunction. For the majority of them, the association of clinical, laboratory, and imaging findings are needed to narrow the differential diagnosis. In this article, we will review and describe the rarer diffuse liver diseases including drug-related liver disease, inflammatory and infectious diseases, and deposition disorders such as amyloidosis, glycogen storage disease, Wilson's disease, and alpha-1 antitrypsin deficiency. Abdominal radiologists should be familiar with the imaging features of different types of diffuse liver diseases to help the multidisciplinary team involved in the treatment of these patients. The data related to some of these conditions are scarce and sometimes experimental, but we want to demonstrate to the reader the value of imaging techniques in their analysis and introduce the potential of new imaging methods.

Schistosoma mansoni Egg-Secreted Antigens Activate Hepatocellular Carcinoma-Associated Transcription Factors c-Jun and STAT3 in Hamster and Human Hepatocytes

Clinical data have provided evidence that schistosomiasis can promote hepatocellular carcinogenesis. c-Jun and STAT3 are critical regulators of liver cancer development and progression. The aim of the present study was to investigate the hepatocellular activation of c-Jun and STAT3 by Schistosoma mansoni infection. Expression and function of c-Jun and STAT3 as well as proliferation and DNA repair were analyzed by western blotting, electrophoretic mobility-shift assay, and immunohistochemistry in liver of S. mansoni-infected hamsters, Huh7 cells, primary hepatocytes, and human liver biopsies. Hepatocellular activation of c-Jun was demonstrated by nuclear translocation of c-Jun, enhanced phosphorylation (Ser73), and AP-1/DNA-binding in response to S. mansoni infection. Nuclear c-Jun staining pattern around lodged eggs without ambient immune reaction, and directionally from granuloma to the central veins, suggested that substances released from schistosome eggs were responsible for the observed effects. In addition, hepatocytes with c-Jun activation show cell activation and DNA double-strand breaks. These findings from the hamster model were confirmed by analyses of human biopsies from patients with schistosomiasis. Cell culture experiments finally demonstrated that activation of c-Jun and STAT3 as well as DNA repair were induced by an extract from schistosome eggs (soluble egg antigens) and culture supernatants of live schistosome egg (egg-conditioned medium), and in particular by IPSE/alpha-1, the major component secreted by live schistosome eggs. The permanent activation of hepatocellular carcinoma-associated proto-oncogenes such as c-Jun and associated transcription factors including STAT3 by substances released from tissue-trapped schistosome eggs may be important factors contributing to the development of liver cancer in S. mansoni-infected patients. Therefore, identification and therapeutic targeting of the underlying pathways is a useful strategy to prevent schistosomiasis-associated carcinogenesis.

Parasitic Liver Infections: Imaging Findings and Strategies for Timely Diagnosis

There are a number of parasitic infections that can affect the liver and biliary tree. These infections can be primarily related to the liver or can include secondary hepatic involvement. Imaging can narrow down the differential diagnosis in the appropriate clinical setting, and can even clinch the diagnosis with some pathognomonic findings. The various imaging modalities can also identify disease extent, help guide management, and demonstrate response to treatment. This pictorial essay will give an overview of parasitic liver infections, and will discuss the best imaging strategies and the key imaging features to help make a timely accurate diagnosis.

Schistosome Egg Migration: Mechanisms, Pathogenesis and Host Immune Responses

Many parasitic worms possess complex and intriguing life cycles, and schistosomes are no exception. To exit the human body and progress to their successive snail host, Schistosoma mansoni eggs must migrate from the mesenteric vessels, across the intestinal wall and into the feces. This process is complex and not always successful. A vast proportion of eggs fail to leave their definite host, instead becoming lodged within intestinal or hepatic tissue, where they can evoke potentially life-threatening pathology. Thus, to maximize the likelihood of successful egg passage whilst minimizing host pathology, intriguing egg exit strategies have evolved. Notably, schistosomes actively exert counter-inflammatory influences on the host immune system, discreetly compromise endothelial and epithelial barriers, and modulate granuloma formation around transiting eggs, which is instrumental to their migration. In this review, we discuss new developments in our understanding of schistosome egg migration, with an emphasis on S. mansoni and the intestine, and outline the host-parasite interactions that are thought to make this process possible. In addition, we explore the potential immune implications of egg penetration and discuss the long-term consequences for the host of unsuccessful egg transit, such as fibrosis, co-infection and cancer development.

Schistosomal liver fibrosis and hepatocellular carcinoma - case series of patients submitted to liver transplantation

Schistosomiasis affects approximately 207 million people in 76 countries. The association between hepatocellular carcinoma and Schistosoma mansoni infection has been investigated. Studies using animal models suggest that the parasite may accelerate the oncogenic process when combined with other factors, such as hepatitis C virus infection or exposure to a carcinogen. Herein, we report a case series of six hepatocellular carcinoma patients from Northeast Brazil, with negative serology for both hepatitis B and C virus, submitted to liver transplantation, whose explant showed evidence of schistosomal liver fibrosis. Since all patients enrolled in this study were submitted to liver transplantation, we were able to access the whole explanted liver and perform histopathological analysis, which is often not possible in other situations. Although 50% of them showed signs of liver failure, no cirrhosis or any liver disease other than schistosomal fibrosis had been detected. These uncommon findings suggest that Schistosoma mansoni infection might predispose to hepatocellular carcinoma development, regardless of the absence of other risk factors.

Metabolomic applications in hepatocellular carcinoma: toward the exploration of therapeutics and diagnosis through small molecules

Hepatocellular carcinoma (HCC), a complex public health issue that is the most common primary hepatic malignancy, remains the highest incidence in developing countries and is showing sustained growth across the developed world.

Unexpected hosts: imaging parasitic diseases

Radiologists seldom encounter parasitic diseases in their daily practice in most of Europe, although the incidence of these diseases is increasing due to migration and tourism from/to endemic areas. Moreover, some parasitic diseases are still endemic in certain European regions, and immunocompromised individuals also pose a higher risk of developing these conditions. This article reviews and summarises the imaging findings of some of the most important and frequent human parasitic diseases, including information about the parasite's life cycle, pathophysiology, clinical findings, diagnosis, and treatment. We include malaria, amoebiasis, toxoplasmosis, trypanosomiasis, leishmaniasis, echinococcosis, cysticercosis, clonorchiasis, schistosomiasis, fascioliasis, ascariasis, anisakiasis, dracunculiasis, and strongyloidiasis. The aim of this review is to help radiologists when dealing with these diseases or in cases where they are suspected. Teaching Points • Incidence of parasitic diseases is increasing due to migratory movements and travelling. • Some parasitic diseases are still endemic in certain regions in Europe. • Parasitic diseases can have complex life cycles often involving different hosts. • Prompt diagnosis and treatment is essential for patient management in parasitic diseases. • Radiologists should be able to recognise and suspect the most relevant parasitic diseases.