Chronic Hepatitis B Virus Infection Associated with Increased Colorectal Cancer Risk in Taiwanese Population

Sequential Treatment of Metastatic Colorectal Cancer in Taiwan: Real-World Evidence From Regorafenib and Trifluridine/Tipiracil Use

OBJECTIVE

This study aims to evaluate the real-world effectiveness and safety of sequential treatment with regorafenib and trifluridine/tipiracil (FTD-TPI) in patients with metastatic colorectal cancer (mCRC) in Taiwan.

METHODS

Data were obtained from Taiwan's National Health Insurance Research Database (NHIRD) to assess clinical outcomes in mCRC patients who were treated with both drugs in either sequential order from 2016 to 2019. Overall survival (OS) was analyzed using Kaplan-Meier curves and Cox's proportional hazard models, with adjustments made for age, gender, Quan-CCI score, presence of liver metastases, number of metastatic sites, and the use of anti-epidermal growth factor receptor medications. Additionally, age-stratified subgroups and sensitivity analyses were conducted to examine the robustness of our findings.

RESULTS

Five hundred and twenty-eight patients receiving both study drugs were included. The regorafenib/FTD-TPI group demonstrated a longer median OS of 14.1 months compared with 10.2 months in the FTD-TPI/regorafenib group (p = 0.007). The survival benefit for the regorafenib/FTD-TPI sequence remained significant after adjustment (adjusted HR, 1.49; p = 0.002). The mean treatment duration was also longer for regorafenib/FTD-TPI than FTD-TPI/regorafenib (337 vs. 214 days; p < 0.01). No significant difference between the sequential treatment groups was observed in any adverse event of interest. Both subgroup and sensitivity analyses yielded outcomes consistent with the main analysis.

CONCLUSION

The findings indicated that initiating treatment with regorafenib followed by FTD-TPI had superior clinical outcomes compared with the reverse sequence among mCRC patients. This study offers real-world evidence for clinical decision-making and treatment optimization.

Epidemiology of colorectal cancer: A review with special emphasis on India

Colorectal cancer (CRC) is a common malignancy and cause for death around the world. In India, it ranks as the fourth most incident cancer in both sexes, with 64,863 cases and 38,367 deaths in 2022. With such high mortality, CRC survival in India is way lesser than that of developed countries. While western countries are facing an overall decline in CRC incidence, various regions in India are seeing an increasing trend. Within India, urban regions have markedly higher incidence than rural. Risk factors include consumption of red and processed meat, fried and sugary food, smoking and alcohol, comorbidities such as obesity, diabetes and inflammatory bowel disease (IBD), family history of CRC, adenomas and genetic syndromes, radiation exposure, pesticides and asbestos. Consumption of nutrient-rich well-balanced diets abundant in vegetables, dairy products, whole grains, nuts and legumes combined with physical activity are protective against CRC. Besides these, metformin, aspirin and micronutrient supplements were inversely associated with the development of CRC. Since a considerable proportion of CRC burden is attributed to modifiable risk factors, execution of population level preventive strategies is essential to limit the growing burden of CRC. Identifying the necessity, in this review, we explore opportunities for primary prevention and for identifying high-risk populations of CRC to control its burden in the near future.

Microbiome Differences in Colorectal Cancer Patients and Healthy Individuals: Implications for Vaccine Antigen Discovery

Background

Colorectal cancer (CRC) is the third most prevalent cancer worldwide, with numerous risk factors contributing to its development. Recent research has illuminated the significant role of the gut microbiota in CRC pathogenesis, identifying various microbial antigens as potential targets for vaccine development.

Aim

This review aimed at exploring the potential sources of microbial antigens that could be harnessed to create effective CRC vaccines and understand the role of microbiome-CRC interactions in carcinogenesis.

Methods

A comprehensive search of original research and review articles on the pathological links between key microbial candidates, particularly those more prevalent in CRC tissues, was conducted. This involved extensive use of the PubMed and Medline databases, as well as the Google Scholar search engine, utilizing pertinent keywords. A total of one hundred and forty-three relevant articles in English, mostly published between 2018 and 2024, were selected.

Results

Numerous microbes, particularly bacteria and viruses, are significantly overrepresented in CRC tissues and have been shown to promote tumorigenesis by inducing inflammation and modulating the immune system. This makes them promising candidates for antigens in the development of CRC vaccines.

Conclusion

The selection of microbial antigens focuses on their capacity to trigger a strong immune response and their link to tumor presence and progression. Identifying and validating these antigens through preclinical testing is essential in developing a CRC vaccine.

Association of Chronic Hepatitis B With Colorectal Cancer and Its Dual Impact on Colorectal Liver Metastasis: A Narrative Review

Viral hepatitis B is infamous for being contracted in young adulthood and adolescence, as high-risk behaviors like unprotected sexual intercourse and intravenous drug abuse are common. Most infections caused by the hepatitis B virus (HBV) are cleared without any long-term sequelae, but some may persist and cause chronic hepatitis B (CHB). This chronicity may produce a state of prolonged inflammation and significantly increase the risk of developing colorectal adenomas (CRA) and colorectal carcinomas (CRC). The aim of this review is to deep-dive into the mechanisms by which CHB may predispose a patient to develop CRA and, more grimly, CRC. It also focuses on studying the influence of CHB on colorectal cancer liver metastases (CRLM). We conducted a comprehensive literature search using databases like PubMed and Google Scholar, focusing on studies that investigate the role of HBV in colorectal carcinogenesis and CRLM rates in patients suffering from CHB. Chronic inflammation, viral protein interactions with tumor suppressor genes, alteration of cellular pathways such as wingless-related integration site (Wnt) signaling, and extrahepatic accumulation of hepatitis B surface antigen (HBsAg) were the key mechanisms identified. Quite peculiarly, CHB, which is thought to increase the risk for CRA, seemed to protect against CRLM probably due to its sclerosing effect on the liver parenchyma and due to certain immune-mediated mechanisms that suppress tumor growth. Nonetheless, high viral count or the presence of hepatitis B envelope antigen (HBeAg) was found to increase the risk for CRLM, potentially due to increased angiogenesis in the liver. These findings provide convincing evidence that enhanced colonoscopic screening and stronger management protocols for patients suffering from it have the potential to reduce the risk of developing CRC and CRLM.

The association between hepatic viral infections and cancers: a cross-sectional study in the Taiwan adult population

BACKGROUND

Hepatitis B (HBV) and hepatitis C (HCV) viruses are diseases of global public health concern and are associated with liver cancer. Recent studies have revealed associations between hepatic viral infections and extrahepatic cancers. This study aimed to explore the associations between hepatitis B and C viruses and cancer at baseline in the Taiwan Biobank database while controlling for a wide range of confounding variables.

METHODS

In a cross-sectional study of adults aged > 20 years, we compared the distribution of demographic factors, lifestyle, and comorbidities between viral and nonviral hepatic groups using the chi-square test. Univariate and multivariate logistic regressions were performed to observe the associations between hepatitis B and C viral infections and cancers by estimating the odds ratio (OR) and 95% confidence interval (CI). Multivariate regression analysis was adjusted for sociodemographic factors, lifestyle, and comorbidities.

RESULTS

From the database, 2955 participants were identified as having HCV infection, 15,305 as having HBV infection, and 140,108 as the nonviral group. HBV infection was associated with an increased likelihood of liver cancer (adjusted OR (aOR) = 6.60, 95% CI = 3.21-13.57, P < 0.001) and ovarian cancer (aOR = 4.63, 95% CI = 1.98-10.83, P = 0.001). HCV infection was observed to increase the likelihood of liver cancer (aOR = 4.90, 95% CI = 1.37-17.53, P = 0.015), ovarian cancer (aOR = 8.50, 95% CI = 1.78-40.69, P = 0.007), and kidney cancer (aOR = 12.89, 95% CI = 2.41-69.01, P = 0.003).

CONCLUSION

Our findings suggest that hepatic viral infections are associated with intra- and extrahepatic cancers. However, being cross-sectional, causal inferences cannot be made. A recall-by-genotype study is recommended to further investigate the causality of these associations.

Exploring the Relationship between the Gut Mucosal Virome and Colorectal Cancer: Characteristics and Correlations

The fecal virome has been reported to be associated with CRC. However, little is known about the mucosal virome signature in CRC. This study aimed to determine the viral community within CRC tissues and their contributions to colorectal carcinogenesis. Colonic mucosal biopsies were harvested from patients with CRC (biopsies of both neoplasia and adjacent normal tissue (CRC-A)) and healthy controls (HC). The shot-gun metagenomic sequencing of virus-like particles (VLPs) was performed on the biopsies. Viral community, functional pathways, and their correlations to clinical data were analyzed. Fluorescence in situ hybridizations (FISH) for the localization of viruses in the intestine was performed, as well as quantitative PCR for the detection of Torque teno virus load in human mucosal VLP DNA. A greater number and proportion of core species were found in CRC tissues than in CRC-A and HC tissues. The diversity of the mucosal virome in CRC tissues was significantly increased compared to that in HC and CRC-A tissues. The mucosal virome signature of CRC tissues were significantly different from those of HC and CRC-A tissues at the species level. The abundances of eukaryotic viruses from the Anelloviridae family and its sub-species Torque teno virus (TTV) were significantly higher in CRC patients than in HC. Furthermore, increased levels of TTV in the intestinal lamina propria were found in the CRC group. Multiple viral functions of TTV associated with carcinogenesis were enriched in CRC tissues. We revealed for the first time that the mucosal virobiota signature of CRC is characterized by a higher diversity and more eukaryotic viruses. The enrichment of TTV species in CRC tissues suggests that they may play an oncogenic role in CRC. Targeting eukaryotic viruses in the gut may provide novel strategies for the prevention and treatment of CRC.

Association between nonalcoholic fatty liver disease and colorectal cancer: A population-based study

Colorectal cancer (CRC) and nonalcoholic fatty liver disease (NAFLD) have high prevalence rates and place a considerable burden on the health-care industry. The association between both diseases is controversial. Our aim was to examine the association between NAFLD and CRC. Using data extracted from the Taiwan National Health Insurance Research Database (NHIRD) from 2000 to 2015, we enrolled 60 298 patients with NAFLD. Of these, 52,986 met the inclusion criteria. A comparison group was selected using 4-fold propensity score matching by age, sex, and year of index date. The primary outcome was the cumulative incidence of CRC in patients with NAFLD. Over a mean follow-up period of 8.5 years, 160 new cases of CRC were identified. The incidence rate of CRC was higher in the NAFLD group (12.23 per 100,000 person-years) than in the comparison cohort (6.0 per 100,000 person-years). Cox proportional hazards regression analysis revealed that the adjusted hazard ratio (HR) of CRC was 1.259 in the study group (95% confidence interval [CI]: 1.047-1.486, P = .003). Using Kaplan-Meier analysis, we ascertained that the cumulative incidence of CRC was significantly high in the NAFLD group. Patients older than 50 years, with diabetes mellitus (DM), and with chronic liver disease also exhibited a high risk of CRC. NAFLD was associated with a high risk of CRC. CRC occurs more frequently in patients with NAFLD aged between 50 and 59 years and those older than 60 years with comorbidities, including DM and chronic liver disease. Physicians should consider the subsequent risk of CRC when treating patients with NAFLD.

Dynamic impact of virome on colitis and colorectal cancer: Immunity, inflammation, prevention and treatment

The gut microbiome includes a series of microorganism genomes, such as bacteriome, virome, mycobiome, etc. The gut microbiota is critically involved in intestine immunity and diseases, including inflammatory bowel disease (IBD) and colorectal cancer (CRC); however, the underlying mechanism remains incompletely understood. Clarifying the relationship between microbiota and inflammation may profoundly improve our understanding of etiology, disease progression, patient management, and the development of prevention and treatment. In this review, we discuss the latest studies of the influence of enteric viruses (i.e., commensal viruses, pathogenic viruses, and bacteriophages) in the initiation, progression, and complication of colitis and colorectal cancer, and their potential for novel preventative approaches and therapeutic application. We explore the interplay between gut viruses and host immune systems for its effects on the severity of inflammatory diseases and cancer, including both direct and indirect interactions between enteric viruses with other microbes and microbial products. Furthermore, the underlying mechanisms of the virome's roles in gut inflammatory response have been explained to infer potential therapeutic targets with examples in specific clinical trials. Given that very limited literature has thus far discussed these various topics with the gut virome, we believe these extensive analyses may provide insight into the understanding of the molecular pathogenesis of IBD and CRC, which could help add the design of improved therapies for these important human diseases.

Meta-analysis of fecal viromes demonstrates high diagnostic potential of the gut viral signatures for colorectal cancer and adenoma risk assessment

INTRODUCTION

Viruses have been reported as inducers of tumorigenesis. Little studies have explored the impact of the gut virome on the progression of colorectal cancer. However, there is still a problem with the repeatability of viral signatures across multiple cohorts.

OBJECTIVES

The present study aimed to reveal the repeatable gut vial signatures of colorectal cancer and adenoma patients and decipher the potential of viral markers in disease risk assessment for diagnosis.

METHODS

1,282 available fecal metagenomes from 9 published studies for colorectal cancer and adenoma were collected. A gut viral catalog was constructed via a reference-independent approach. Viral signatures were identified by cross-cohort meta-analysis and used to build predictive models based on machine learning algorithms. New fecal samples were collected to validate the generalization of predictive models.

RESULTS

The gut viral composition of colorectal cancer patients was drastically altered compared with healthy, as evidenced by changes in some Siphoviridae and Myoviridae viruses and enrichment of Microviridae, whereas the virome variation in adenoma patients was relatively low. Cross-cohort meta-analysis identified 405 differential viruses for colorectal cancer, including several phages of Porphyromonas, Fusobacterium, and Hungatella that were enriched in patients and some control-enriched Ruminococcaceae phages. In 9 discovery cohorts, the optimal risk assessment model obtained an average cross-cohort area under the curve of 0.830 for discriminating colorectal cancer patients from controls. This model also showed consistently high accuracy in 2 independent validation cohorts (optimal area under the curve, 0.906). Gut virome analysis of adenoma patients identified 88 differential viruses and achieved an optimal area under the curve of 0.772 for discriminating patients from controls.

CONCLUSION

Our findings demonstrate the gut virome characteristics in colorectal cancer and adenoma and highlight gut virus-bacterial synergy in the progression of colorectal cancer. The gut viral signatures may be new targets for colorectal cancer treatment. In addition, high repeatability and predictive power of the prediction models suggest the potential of gut viral biomarkers in non-invasive diagnostic tests of colorectal cancer and adenoma.

Clinical spectrum of rectal cancer identifies hallmarks of early-onset patients and next-generation treatment strategies

BACKGROUND

The incidence of colorectal cancer is increasing among young adults and more rectal cancers are reported. This study aimed to identify the clinical features specific for early-onset rectal cancer and provide insights on cancer management.

METHODS

Early-onset (<50 years) and late-onset (≥50 years) rectal cancer patients from a referral tertiary care center (SYSU cohort) and Surveillance Epidemiology and End Results database (SEER cohort) were included to perform a comprehensive comparison on clinical information.

RESULTS

A total of 552 and 80,341 patients with stages I-III rectal cancer were included in the SYSU and SEER cohorts, respectively. In the SYSU cohort, early-onset diseases had significantly higher prevalence of family history of cancer and history of HBV infection and lower incidence of comorbidities (p < 0.05). In addition, early-onset patients presented more frequently with advanced node stage (N2 stage: 16.9 vs. 9.3%, p = 0.017) and high-risk features, including mucinous or signet cell carcinomas (21.8 vs. 12.9%, p = 0.014), poorly differentiated tumors (28.8 vs. 15.4%, p = 0.002), and perineural invasion (14.5 vs. 7.9%, p = 0.027) compared with late-onset patients. However, early-onset patients received more neoadjuvant (18.5 vs. 11.2%, p = 0.032) and adjuvant treatments (71.0 vs. 45.8%, p < 0.001), and they had better overall survival in both SYSU (HR 0.57, 95% CI: 0.34-0.95; p = 0.029) and SEER (HR 0.38, 95% CI: 0.37-0.40; p < 0.001) cohorts.

CONCLUSION

Early-onset rectal cancers are distinct from late-onset cases in clinicopathological features, treatment modalities, and outcomes. The clinical trials and studies that are specific for young populations are needed to develop optimal strategies for cancer screening, treatment, and surveillance.

Hepatitis B infection is causally associated with extrahepatic cancers: A Mendelian randomization study

BACKGROUND

Evidence from observational studies suggests that chronic hepatitis B virus (HBV) infection is associated with extrahepatic cancers. However, the causal association between chronic HBV infection and extrahepatic cancers remains to be determined.

METHODS

We performed two-sample Mendelian randomization (MR) to investigate whether chronic HBV infection is causally associated with extrahepatic cancers. We identified four independent genetic variants strongly associated (P-value < 5 × 10-8) with the exposure, chronic HBV infection in 1371 cases and 2938 controls of East Asian ancestry in Korea, which were used as instrumental variables. Genome-wide association summary level data for outcome variables, that included cancer of the biliary tract, cervix, colorectum, endometrium, esophagus, gastric, hepatocellular carcinoma, lung, ovary and pancreas were obtained from Biobank Japan.

FINDINGS

Using the multivariable inverse variance weighted method, we found genetic liability to chronic HBV infection causally associated with extrahepatic cancers including cervical cancer (odds ratio [OR] = 1.57, 95% confidence interval [CI] = 1.29-1.91, P-value = 0.0001) and gastric cancer (OR = 1.12, 95% CI = 1.05-1.19, P-value = 0.0001). Moreover, chronic HBV infection (OR = 1.20, 95% CI = 1.07-1.34, P-value = 0.0021) was causally associated with hepatocellular carcinoma, supporting a well-established association between chronic HBV infection and hepatocellular carcinoma.

INTERPRETATION

Our MR analysis revealed that chronic HBV infection is causally associated with extrahepatic cancers including cervical and gastric cancers.

FUNDING

None.

Metabolic Dysfunction-Associated Fatty Liver Disease Increases Colon Cancer Risk: A Nationwide Cohort Study

INTRODUCTION

The association between nonalcoholic fatty liver disease (NAFLD) and colorectal cancer (CRC) has been controversial. Using the new consensus-driven definition, we evaluated the association of metabolic dysfunction-associated fatty liver disease (MAFLD) with the risk of developing CRC.

METHODS

From a nationwide health screening database, we included 8,933,017 participants (48.6% male) aged 40-64 years between 2009 and 2010. Participants were categorized by the presence of fatty liver disease (FLD)-NAFLD and MAFLD, separately-and by the combination of the 2 definitions: neither FLD, NAFLD only, MAFLD only, or both FLD. The primary outcome was the development of CRC.

RESULTS

Among the participants, 2,517,330 (28.2%) had NAFLD, and 3,337,122 (37.4%) had MAFLD, whereas 2,465,151 (27.6%) met both NAFLD and MAFLD definitions. Over a median follow-up period of 10.1 years, 60,888 new CRC cases developed. NAFLD and MAFLD were each associated with a significantly higher risk of developing CRC. When the neither FLD group was the reference, multivariable-adjusted hazard ratios (95% confidence interval) for CRC were 1.16 (1.06-1.28) in the NAFLD only group, 1.18 (1.16-1.20) in the both FLD group, and 1.32 (1.28-1.35) in the MAFLD only group. The presence of advanced liver fibrosis further increased CRC risk in each FLD group.

DISCUSSION

FLD was associated with a higher risk of CRC development. CRC risk was higher in the presence of MAFLD, especially when accompanied by liver fibrosis.

The Roles of the Virome in Cancer

Viral infections as well as changes in the composition of the intestinal microbiota and virome have been linked to cancer. Moreover, the success of cancer immunotherapy with checkpoint inhibitors has been correlated with the intestinal microbial composition of patients. The transfer of feces-which contain mainly bacteria and their viruses (phages)-from immunotherapy responders to non-responders, known as fecal microbiota transplantation (FMT), has been shown to be able to convert some non-responders to responders. Since phages may also increase the response to immunotherapy, for example by inducing T cells cross-reacting with cancer antigens, modulating phage populations may provide a new avenue to improve immunotherapy responsiveness. In this review, we summarize the current knowledge on the human virome and its links to cancer, and discuss the potential utility of bacteriophages in increasing the responder rate for cancer immunotherapy.

Chronic Viral Hepatitis Is Associated with Colorectal Neoplasia: A Systematic Review and Meta-Analysis

BACKGROUND

Chronic viral hepatitis is associated with a wide range of extrahepatic diseases; however, evidence on a link between chronic viral hepatitis and colorectal neoplasia is still lacking.

AIMS

To analyze the association between chronic viral hepatitis and prevalence of colorectal neoplasia.

METHODS

A systematic review of articles published in the MEDLINE, EMBASE, and Cochrane Library between 2000 and 2020 was performed. Subgroup analyses based on the types of colorectal neoplasia and the etiology of chronic viral hepatitis were conducted.

RESULTS

Twelve eligible studies with 48,428 hepatitis B virus (HBV) patients and 46,561 hepatitis C virus (HCV) patients were included. Chronic viral hepatitis was significantly associated with an increased risk of both colorectal adenoma (odds ratio [OR], 1.53; 95% confidence interval [CI], 1.16-2.02; I² = 83%) and colorectal cancer (CRC) (OR, 1.32; 95% CI, 1.08-1.61; I² = 94%). The etiology of chronic viral hepatitis was an independent factor related to heterogeneity for CRC subgroup analysis revealed an increased risk of CRC in both HBV (OR, 1.18; 95% CI, 1.09-1.27; I² = 37%) and HCV (OR, 1.88; 95% CI, 1.78-1.97; I² = 0%). HCV was associated with an increased risk of colorectal adenoma (OR, 1.48; 95% CI, 1.22-1.79; I² = 0%); however, HBV was not associated with an increased risk of colorectal adenoma and had considerable heterogeneity (OR, 1.65; 95% CI, 0.88-3.09; I² = 90%).

CONCLUSION

Our meta-analysis showed that chronic viral hepatitis is associated with an increased risk of colorectal neoplasia. The strategy of stricter screening colonoscopy may benefit from patients with chronic viral hepatitis.

Associations between hepatitis B virus infection and risk of colorectal Cancer: a population-based prospective study

Background

Previous studies have observed a close association between hepatitis B virus (HBV) infection and hepatocellular carcinoma (HCC) as well as extrahepatic cancers. However, research concerning the effect of HBV infection on the risk of colorectal cancer (CRC) is rare and inconsistent. This study aims to determine the relationship between HBV infection and new-onset CRC.

Methods

We prospectively examined the relationship between HBV infection and new-onset CRC among 93,390 participants from Kailuan Cohort study. Cox proportional hazards regression models, subgroup analyses and competing risk analyses were used to evaluate the association between HBV infection and the risk of new-onset CRC.

Results

During a median follow-up of 11.28 years, 448 incident CRC cases were identified. The adjusted HR (95%confidence interval (CI)) for the association of HBsAg Seropositive with CRC was 1.85(1.15 ~ 2.96) in the Cox regression. Subgroup analyses showed that the HBsAg seropositive group was associated with increased risk of new-onset CRC among male, middle-aged, normal weight, smokers and non-drinker participants, respectively. A positive association of HBV infection with the risk of CRC was observed in the adjusted sub-distribution proportional hazards (SD) models (HR_SD = 1.77, 95% CI:1.11–2.84) and cause-specific hazards (CS) models (HR_CS = 1.79, 95% CI: 1.13–2.91).

Conclusions

Our results have found a significant association between HBV infection and the risk of incident CRC among Chinese participants.

Trial registration

Kailuan study, ChiCTR–TNRC–11001489. Registered 24 August 2011 - Retrospectively registered, http:// http://www.chictr.org.cn/showprojen.aspx?proj=8050

Hepatitis B virus-induced hepatocarcinogenesis: A virological and oncological perspective

Hepatitis B virus (HBV) is a partially double-stranded DNA virus associated with hepatocellular carcinoma (HCC). The viral integration into the hepatocyte genome, the viral protein-induced oncogenesis, the increased hepatocyte turnover and the chronic inflammatory response towards HBV are all hypothesized mechanisms for the development of HCC. The fact that HBV infection and HCC prevalence show different correlations in various regions of the world indicates that there may be virus-independent phenomena for cancer development in these regions. From this point of view, it is important to review our knowledge and to examine the relationship between HBV and HCC in the light of current data. In this article, we investigate the relationship between HBV and HCC by presenting epidemiological and microbiological data, accompanied by the principles of viral oncogenesis.

Patients With Chronic Hepatitis C Virus Infection Are at an Increased Risk of Colorectal Cancer: A Nationwide Population-Based Case-Control Study in Taiwan

Aim

Studies evaluating colorectal cancer (CRC) risk associated with chronic hepatitis C virus (HCV) infection are limited.

Methods

In this case-control study, we identify 67,670 CRC cases newly diagnosed from 2005 to 2011 and randomly selected 67,670 controls without HCV and CRC from the same database, frequency matched by age and sex of cases.

Results

Results of logistic regression analysis revealed that the adjusted odds ratio (aOR) of CRC was 1.16 (95% confidence interval [CI] = 1.08–1.24, p < 0.001) in association with chronic HCV. The CRC risk was slightly greater for women than for men. The risk decreased with age, with the aOR decreased from 2.26 (95% CI = 1.32–3.87, p = 0.003) in patients under 45 years old to 1.31 (95% CI = 1.10–1.55, p = 0.03) in patients aged 50–59, and 1.10 (95% CI = 1.00–1.22, p = 0.061) in patients aged over 70.

Conclusions

Our findings suggested that patients with chronic HCV infection are at an elevated risk of developing CRC. Our data also imply that the CRC prevention programs are needed to target younger HCV patients.

The Viral Janus: Viruses as Aetiological Agents and Treatment Options in Colorectal Cancer

In recent years, our understanding of the importance of microorganisms on and within our bodies has been revolutionized by the ability to characterize entire microbial communities. No more so is this true than in cases of disease. Community studies have revealed strong associations between microbial populations and disease states where such concomitance was previously absent from aetiology: including in cancers. The study of viruses, in particular, has benefited from the development of new community profiling techniques and we are now realising that their prominence within our physiology is nearly as broad as the diversity of the organisms themselves. Here, we examine the relationship between viruses and colorectal cancer (CRC), the leading cause of gastrointestinal cancer-related death worldwide. In CRC, viruses have been suggested to be involved in oncogenesis both directly, through infection of our cells, and indirectly, through modulating the composition of bacterial communities. Interestingly though, these characteristics have also led to their examination from another perspective—as options for treatment. Advances in our understanding of molecular and viral biology have caused many to look at viruses as potential modular biotherapeutics, where deleterious characteristics can be tamed and desirable characteristics exploited. In this article, we will explore both of these perspectives, covering how viral infections and involvement in microbiome dynamics may contribute to CRC, and examine ways in which viruses themselves could be harnessed to treat the very condition their contemporaries may have had a hand in creating.

Gut eukaryotic virome in colorectal carcinogenesis: Is that a trigger?

The human gut microbiota is composed of bacteria and viruses that might be associated with colorectal cancer (CRC) onset and progression. Indeed, although viral infections have been reported to be the primary trigger in many diseases, the role of eukaryotic viruses populating the gut mucosa during early colorectal carcinogenesis is underinvestigated. Human eukaryotic viruses in the gut were found to induce alterations of the immune homeostasis so that some viral-dependent mechanisms likely able to induce DNA alterations in the bowel wall have been proposed, although no demonstration is available yet. However, thanks to the latest advancements in computational biology and the implementation of the bioinformatic pipelines, the option of establishing a direct causative link between intestinal virome and CRC will be possible soon, hopefully paving the way to innovative therapeutic strategies blocking or reverting the CRC pathogenesis.

Viruses in Cancers of the Digestive System: Active Contributors or Idle Bystanders?

The human virome, which is a collection of all the viruses that are present in the human body, is increasingly being recognized as an essential part of the human microbiota. The human gastrointestinal tract and related organs (e.g., liver, pancreas, and gallbladder)-composing the gastrointestinal (or digestive) system-contain a huge number of viral particles which contribute to maintaining tissue homeostasis and keeping our body healthy. However, perturbations of the virome steady-state may, both directly and indirectly, ignite/sustain oncogenic mechanisms contributing to the initiation of a dysplastic process and/or cancer progression. In this review, we summarize and discuss the available evidence on the association and role of viruses in the development of cancers of the digestive system.