Meta-analysis of bivariate P values

AIM: To propose a new meta-analysis method for bivariate P value which account for the paired structure.

METHODS: Studies that look to test two different features from the same sample gives rise to bivariate P value. A relevant example of this is testing for periodicity as well expression from time-course gene expression studies. Kocak et al (2010) uses George and Mudholkar’ (1983) “Difference of Two Logit-Sums” method to pool bivariate P value across independent experiments, assuming independence within a pair. As bivariate P value need not to be independent within a given study, we propose a new meta-analysis approach for pooling bivariate P value across independent experiments, which accounts for potential correlation between paired P-values. We compare the “Difference of Two Logit Sums”method with our novel approach in terms of their sensitivity and specificity through extensive simulations by generating P value samples from most commonly used tests namely, Z test, t test, chi-square test, and F test, with varying sample sizes and correlation structure.

RESULTS: The simulations results showed that our new meta-analysis approach for correlated and uncorrelated bivariate P value has much more desirable sensitivity and specificity features compared to the existing method, which treats each member of the paired P value as independent. We also compare these meta-analysis approaches on bivariate P value from periodicity and expression tests of 4936 S.Pombe genes from 10 independent time-course experiments and we showed that our new approach ranks the periodic, conserved, and cycling genes significantly higher, and detects many more periodic, “conserved” and “cycling” genes among the top 100 genes, compared to the ‘Difference of Two Logit-Sums’ method. Finally, we used our meta-analytic approach to compare the relative evidence in the association of pre-term birth with preschool wheezing versus pre-school asthma.

CONCLUSION: The new meta-analysis method has much better sensitivity and specific characteristics compared to the “Difference of Two-Logit Sums” method and it is not computationally more expensive.

Glycated haemoglobin reduction and fixed ratio combinations of analogue basal insulin and glucagon-like peptide-1 receptor agonists: A systematic review

BACKGROUND

Fixed ratio combinations (FRCs) of analogue basal insulin and glucagon-like peptide-1 receptor agonists are a newer addition to the therapeutic armamentarium for the management of type 2 diabetes mellitus. They reduce treatment complexity by combining two injectables in a single daily injectable, thus potentially improving adherence and persistence. Clinicians wanting to use FRCs would need to choose between members of the class.

AIM

To describe and contrast the glycated haemoglobin reduction of two FRCs of analogue basal insulin and glucagon like peptide-1 receptor agonist in adults with type 2 diabetes mellitus.

METHODS

The following Population, Intervention, Comparison, Outcome question was used for the primary analysis: Among adult patients with type 2 diabetes mellitus [P], what is the effect of iGlarLixi [I] compared to IDegLira [C] for bringing about glycaemic control (as measured by reduction in glycosylated haemoglobin) [O]? The Prisma Statement was used as a guideline for framing this systematic review. We searched PubMed, EMBASE and Cochrane library databases and Clinicaltrials.gov using various keywords and medical search headings related to type 2 diabetes mellitus, iGlarlixi, IDegLira and glycated haemoglobin A1c.

RESULTS

All 14 studies identified by the systematic search met the primary efficacy endpoint of reduction in glycated haemoglobin. There were no head-to-head studies between the FRCs of iGlarlixi and IDegLira, and we therefore did an indirect comparison based on a common comparator of insulin glargine U100. Both iGlarLixi and IDegLira effectively reduce glycated haemoglobin when compared to insulin glargine U100. However, using indirect comparisons, IDegLira had a greater haemoglobin A1c reducing ability (0.6% vs 0.3%). The indirect comparison is limited by the differences between the studies; the fasting blood glucose targets were slightly higher for iGlarLixi studies when compared to the IDegLira studies (4.0-5.0 mmol/L and 4.4-5.6 mmol/L), and the IDegLira study used a greater average dose of insulin glargine when compared to the iGlarLixi studies (66 U/d vs 40 U/d).

CONCLUSION

Both iGlarLixi and IDegLira effectively reduce glycated haemoglobin. Indirect comparisons, using insulin glargine as the common comparator, suggest that IDegLira reduces glycated haemoglobin to a greater extent than iGlarLixi. However, given the limitations of indirect comparisons, robust head to head studies and real-world data would better inform clinician choice and clinical practice guidelines.

Importance of well-designed meta-analyses in assessing medical and surgical treatments

When evaluating the efficacy of medical or surgical treatments, the most robust study design is often considered to be the high-quality randomized clinical trial (RCT). However, the true answer lies in the meta-analysis of high-quality RCTs. While RCTs have their merits, meta-analyses possess two crucial qualities that make them superior: Generalizability and the ability to verify replicability across different trials. A well-designed meta-analysis, defined here as a systematic review that pools data, holds significant advantages over individual RCTs. Retrospective and observational surgical research is prone to biases that are not mutually offsetting; instead, they accumulate. Selection bias, transfer bias, and assessment bias all taint retrospective studies more than randomized trials, making the novel treatment appear more effective than it truly is. Pooling studies suffering from these limitations in a meta-analysis amplifies these biases, causing an overestimation of treatment benefits. This becomes particularly concerning when the treatment itself carries substantial risks, as is often the case in surgical journals. The consequences can result in harm or even death for patients. While a well-designed meta-analysis is the best tool for assessing medical and surgical treatments, a weak meta-analysis amplifies biases and promotes flawed data. Thoughtful readers must become proficient in honing their methodological toolkits, delving deeper into topics like heterogeneity and publication bias. It is essential to avoid wasting time on meta-analyses drawing data from retrospective or observational research regarding surgical treatments.

Radiofrequency ablation with or without transarterial chemoembolization for hepatocellular carcinoma: A systematic review and meta-analysis

AIM: To determine whether combined transarterial chemoembolization (TACE) and radiofrequency ablation (RFA) improve overall and recurrence-free survival (RFS) compared with RFA alone.

METHODS: We reviewed randomized clinical trials (RCTs) comparing overall survival rate as well as recurrence-free rate for hepatocellular carcinoma (HCC) between TACE-RFA therapy and RFA alone published before April 2015 by conducting a systematic review and meta-analysis. Eligible studies were identified by searching PubMed and EMBASE up to April 2015. Additional studies were retrieved via China Medical Collections, Google Scholar or a hand review of the reference lists of the retrieved articles. The summarized relative risks (RRs) with their 95%CIs were estimated using random-effects model. I² statistic was calculated to measure the heterogeneity of RRs across studies and Cochran’s Q test was used to test the statistical significance accordingly. Publication bias was assessed primarily based on visual assessment using a funnel plot, and secondly by using Egger’s regression asymmetry test or Begg’s rank correlation test as appropriate. Meta-regression was implemented to examine potential effect modifiers.

RESULTS: Nine single-center RCTs conducted in China and Japan were included, with a total of 618 patients with HCC; 321 of whom (51.9%) received TACE/RFA therapy and 297 received RFA alone. The pooled RRs with corresponding CIs comparing combined TACE/RFA to RFA alone were 1.12 (1.004-1.26) and 1.20 (1.02-1.41) for 1-year and 3-year survival rates, respectively. Similar positive associations were found for 1-year (1.19; 1.05-1.35) and 3-year (1.44; 1.00-2.07) RFS. The beneficial effect was more evident in patients with medium-sized (3-5 cm) tumors and among the Chinese population.

CONCLUSION: Combined TACE/RFA has a beneficial effect on survival and recurrence rates compared with RFA alone, especially for medium-sized HCC and among Chinese patients.

Blastocystis hominis as a cause of chronic diarrhea in low-resource settings: A systematic review

BACKGROUND

Blastocystis hominis (B. hominis), an anaerobic unicellular protist parasite, is known for its diverse clinical manifestations upon infecting the human gastrointestinal tract. Although globally distributed, it is particularly prevalent in developing nations. Examining the symptoms and treatment outcomes of B. hominis infection in low-resource settings holds immense significance, providing healthcare practitioners with valuable insights to enhance patient care.

AIM

To synthesize existing evidence on the symptomatology and treatment outcomes of B. hominis infection in low-resource settings.

METHODS

Following the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines, a systematic review was conducted. The search spanned electronic databases including PubMed, Scopus, and Google Scholar. After a comprehensive screening process, a thorough examination of the papers, adhering to inclusion and exclusion criteria, and data extraction from eligible studies was conducted. The findings underwent summarization through simple descriptive analysis.

RESULTS

The search yielded 1200 papers, with 17 meeting inclusion criteria. Chronic diarrhea due to B. hominis infection was reported in only two studies, while abdominal pain, diarrhea, flatulence, constipation, and nausea/vomiting emerged as the most commonly documented symptoms. Recovery rates after one week of treatment ranged from 71.8% to 100%, and after two weeks, from 60% to 100%.

CONCLUSION

In low-resource settings, chronic diarrhea resulting from B. hominis infection is infrequent. Common symptoms include abdominal pain, diarrhea, flatulence, constipation, and nausea/vomiting. Post-treatment, clinical outcomes are notably favorable, supporting the recommendation for treatment. Metronidazole is advocated as the first-line agent, with consideration for switching to a second-line option in cases of treatment failure or poor response.

Is COVID-19-induced liver injury different from other RNA viruses?‎

Coronavirus disease 2019 is a pandemic disease caused by a novel RNA coronavirus, SARS coronavirus 2 (SARS-CoV-2), which is implicated in the respiratory system. SARS-CoV-2 also targets extrapulmonary systems, including the gastrointestinal tract, liver, central nervous system and others. SARS-CoV-2, like other RNA viruses, targets the liver and produces liver injury. This literature review showed that SARS-CoV-2-induced liver injury is different from other RNA viruses by a transient elevation of hepatic enzymes and does not progress to liver fibrosis or other unfavorable events. Moreover, SARS-CoV-2-induced liver injury usually occurs in the presence of risk factors, such as nonalcoholic liver fatty disease. This review highlights the important differences between RNA viruses inducing liver injury taking into consideration the clinical, biochemical, histopathological, postmortem findings and the chronicity of liver injury that ultimately leads to liver fibrosis and hepatocellular carcinoma.

Troponin I biomarker as a strong prognostic factor for predicting COVID-19 mortality: A systematic review

BACKGROUND

The increase in circulating Troponin-I in the blood of patients suffering coronavirus disease 2019 (COVID-19) can be a strong prognostic factor for predicting disease poorer outcome.

AIM

To review the literatures to approve this claim systematically.

METHODS

Two blinded reviewers independently screened the titles and abstracts of the manuscripts using the keywords and deeply searching the databanks including PubMed, Scopus, Google Scholar, and Web of knowledge, followed by profoundly appraisement of the full texts to assess the inclusion appropriateness.

RESULTS

The manuscripts entered into our final assessment were categorized as the two groups including 10 manuscripts describing and comparing death and disease-related complications between the subgroups of patients with raised serum troponin level and those with normal ranges of this biomarker and 7 manuscripts comparing the mean level of serum troponin concentration across the survived and non-survived groups. Comparing outcome of COVID-19 disease in the groups with raised troponin level and normal level of this markers showed increased the likelihood of death [hazard ratio (HR) = 4.967, P < 0.001], acute respiratory distress syndrome (HR = 5.914, P < 0.001), acute kidney injury (HR = 3.849, P < 0.001), and intensive care unit (ICU) admission (HR = 3.780, P < 0.001) following raise of troponin. The pooled analysis showed significantly higher concentration of this marker in the survived group compared to non-survived group (weighted mean differences of 22.278, 95%CI: 15.647 to 28.927, P < 0.001).

CONCLUSION

Raising troponin-I on admission can be linked to the increase risk for in-hospital death, acute respiratory distress syndrome, kidney injury, and ICU admission by 4.9, 5.9, 3.8, and 3.7 times as compared to those with initial normal troponin-I concentration. Thus, raising baseline value of troponin-I can be used as a prognostic factor for poor outcome of COVID-19.

Ophthalmic adverse drug reactions: A nationwide detection using hospital databases

AIM: To detect ophthalmic adverse drug reactions (ADRs), that occurred in Portugal from 2000 to 2009, through the utilization of administrative hospital databases. We also intended to compare the results of this methodology with spontaneous reporting.

METHODS: We conducted a retrospective nationwide study using hospital administrative databases, which included all inpatients and outpatients in all public hospitals in Portugal, from 2000 to 2009. We used International Classification of Diseases - 9^th Revision - Clinical Modification (ICD-9-CM) coding data that allowed the detection of ADRs. We used WHO’s definition for ADR. We searched all of ICD-9-CM terms in Ophthalmology for codes that included “drug-induced”, “iatrogenic”, “toxic” and all other that could signal an ADR, such as “362.55 - toxic maculopathy” or “365.03 - steroid responders”, and also “E” codes (codes from E930 to E949.9, that exclude intoxications and errors).

RESULTS: From 11944725 hospitalizations or ambulatory episodes within that period of time, we identified 1524 probable ophthalmic ADRs (corresponding to a frequency of 1.28 per 10000 episodes) and an additional 100 possible ophthalmic ADRs. We used only 4 person-hours in the application of this methodology. A total of 113 spontaneous reports arose from ophthalmic ADRs from 2000 to 2009 in Portugal (frequency of 0.095 per 10000 episodes).To our knowledge, this was the first estimate of the frequency of ophthalmic ADRs through the use of databases, and the first nationwide estimate of ophthalmic ADRs, in Portugal. We identified 1524 probable ADRs and 100 possible ADRs.

CONCLUSION: This database methodology adapted for Ophthalmology may represent a new approach for the detection of ophthalmic ADRs, since these codes exist in the ICD-9-CM classification. Its performance was clearly superior to spontaneous reporting.

Development of donor specific antibodies after SARS-CoV-2 vaccination: What do we know so far?

Vaccination against Coronavirus disease-19 (COVID-19) was pivotal to limit spread, morbidity and mortality. Our aim is to find out whether vaccines against COVID-19 lead to an immunological response stimulating the production of de novo donor specific antibodies (DSAs) or increase in mean fluorescence intensity (MFI) of pre-existing DSAs in kidney transplant recipients (KTRs). This study involved a detailed literature search through December 2^nd, 2023 using PubMed as the primary database. The search strategy incorporated a combination of relevant Medical Subject Headings terms and keywords: "COVID-19", "SARS-CoV-2 Vaccination", "Kidney, Renal Transplant", and "Donor specific antibodies". The results from related studies were collated and analyzed. A total of 6 studies were identified, encompassing 460 KTRs vaccinated against COVID-19. Immunological responses were detected in 8 KTRs of which 5 had increased MFIs, 1 had de novo DSA, and 2 were categorized as either having de novo DSA or increased MFI. There were 48 KTRs with pre-existing DSAs prior to vaccination, but one study (Massa et al) did not report whether pre-existing DSAs were associated with post vaccination outcomes. Of the remaining 5 studies, 35 KTRs with pre-existing DSAs were identified of which 7 KTRs (20%) developed de novo DSAs or increased MFIs. Overall, no immunological response was detected in 452 (98.3%) KTRs. Our study affirms prior reports that COVID-19 vaccination is safe for KTRs, especially if there are no pre-existing DSAs. However, if KTRs have pre-existing DSAs, then an increased immunological risk may be present. These findings need to be taken cautiously as they are based on a limited number of patients so further studies are still needed for confirmation.

Exploring influences and risk of bias of studies on return to sport and work after lateral ankle sprain: A systematic review and meta-analysis

BACKGROUND

Lateral ankle sprains are the most common traumatic musculoskeletal injuries of the lower extremity, with an incidence rate of 15%-20%. The high incidence and prevalence highlights the economic impact of this injury. Ankle sprains lead to a high socioeconomic burden due to the combination of the high injury incidence and high medical expenses. Up to 40% of patients who suffer from an ankle sprain develop chronic ankle instability. Chronic instability can lead to prolonged periods of pain, immobility and injury recurrence. Identification of factors that influence return to work (RTW) and return to sports (RTS) after a lateral ankle sprain (LAS) may help seriously reduce healthcare costs.

AIM

To explore which factors may potentially affect RTW and RTS after sustaining an LAS.

METHODS

EMBASE and PubMed were systematically searched for relevant studies published until June 2023. Inclusion criteria were as follows: (1) Injury including LAS or chronic ankle instability; (2) Described any form of treatment; (3) Assessment of RTW or RTS; (4) Studies published in English; and (5) Study designs including randomized controlled clinical trials, clinical trials or cohort studies. Exclusion criteria were: (1) Studies involving children (age < 16 year); or (2) Patients with concomitant ankle injury besides lateral ankle ligament damage. A quality assessment was performed for each of the included studies using established risk of bias tools. Additionally quality of evidence was assessed using the GRADEpro tool in cases where outcomes were included in the quantitative analysis. A best evidence synthesis was performed in cases of qualitative outcome analysis. For all studied outcomes suitable for quantitative analysis a forest plot was created to calculate the effect on RTW and RTS.

RESULTS

A total of 8904 patients were included in 21 studies, 10 randomized controlled trials, 7 retrospective cohort studies and 4 prospective cohort studies. Fifteen studies were eligible for meta-analysis. The overall RTS rate ranged were 80% and 83% in the all treatments pool and surgical treatments pool, respectively. The pooled mean days to RTS ranged from 23-93 d. The overall RTW rate was 89%. The pooled mean time to RTW ranged from 5.8-8.1 d. For patients with chronic ankle instability, higher preoperative motivation was the sole factor significantly and independently (P = 0.001) associated with the rate of and time to RTS following ligament repair or reconstruction. Higher body mass index was identified as a significant factor (P = 0.04) linked to not resuming sports or returning at a lower level (median 24, range 20-37), compared to those who resumed at the same or higher level (median 23, range 17-38). Patients with a history of psychological illness or brain injury, experienced a delay in their rehabilitation process for sprains with fractures and unspecified sprains. The extent of the delayed rehabilitation was directly proportional to the increased likelihood of experiencing a recurrence of the ankle sprain and the number of ankle-related medical visits. We also observed that 10% of athletes who did return to sport after lateral ankle sprain without fractures described non-ankle-related reasons for not returning.

CONCLUSION

All treatments yielded comparable results, with each treatment potentially offering unique advantages or benefits. Preoperative motivation may influence rehabilitation after LAS. Grading which factor had a greater impact was not possible due to the lack of comparability among the included patients.

Accuracy of early detection of colorectal tumours using stool methylation markers: A meta-analysis

AIM: To evaluate the accuracy of methylation of genes in stool samples for diagnosing colorectal tumours.

METHODS: Electronic databases including PubMed, Web of Science, Chinese Journal Full Text Database and Wanfang Journals Full-text Database were searched to find relevant original articles about methylated genes used in diagnosing colorectal tumours. Quality assessment of diagnostic accuracy studies items were used to evaluate the quality of the included articles, and the Meta-disc 1.4 and SPSS 13.0 software programs were used for data analysis.

RESULTS: Thirty-four articles met the inclusion criteria, and 4151 patients were included. Pooled diagnostic performances of SFRP2 methylation for colorectal cancer (CRC) provided the following results: the sensitivity was 79% (95%CI: 75%-82%), the specificity was 93% (95%CI: 90%-96%), the diagnostic odds ratio (DOR) was 47.57 (95%CI: 20.08-112.72), and the area under the curve was 0.9565. Additionally, the results of accuracy of SFRP2 methylation for detecting colorectal adenomas were as follows: the sensitivity was 43% (95%CI: 38%-49%), the specificity was 94% (95%CI: 91%-97%), the DOR was 11.06 (95%CI: 5.77-21.18), and the area under the curve was 0.9563.

CONCLUSION: Stool-based DNA testing may be useful for non-invasively diagnosing colorectal tumours, and SFRP2 methylation is a promising marker that has great potential in early CRC diagnosis.

Transient elastography (FibroScan) in critical care: Applications and limitations

FibroScan^® is a non-invasive device that assesses the ‘hardness’ (or stiffness) of the liver via the technique of transient elastography. Because fibrous tissue is harder than normal liver, the degree of hepatic fibrosis can be inferred from the liver hardness. This technique is increasingly being employed to diagnose liver fibrosis, even in critically ill patients. It is now being used not only for diagnosis and staging of liver cirrhosis, but also for outcome prognostication. However, the presence of several confounding factors, especially in critically ill patients, may make interpretation of these results unreliable. Through this review we aim to describe the indications and pitfalls of employing FibroScan in patients admitted to intensive care units.

Lipocalin-2 as a biomarker for diabetic nephropathy

Diabetes is a major global public health issue. The prevalence of type 1 diabetes is comparatively static, as hereditary and genetic causes are involved, while type 2 diabetes (T2D) prevalence is increasing day by day. T2D is associated with chronic complications, including diabetic neuropathy (DN), nephropathy, retinopathy, and other complications like diabetic foot. DN is the main complication of both types of diabetes. DN can be diagnosed by routine laboratory tests, microalbuminuria > 300 mg/24 h, and a gradual decrease in glomerular filtration rate. As the appearance of microalbuminuria is a late manifestation, an early marker for renal damage is needed. Lipocalin-2, also known as neutrophil gelatinase-associated lipocalin (NGAL), is a small protein purified from neutrophil granules and a good marker for kidney disease. NGAL is a transporter protein responsible for many physiological processes, such as inflammation, generation of the immune response, and metabolic homeostasis. NGAL has been reported to depict the early changes in renal damage when urine microalbumin is still undetecable. Therefore, elucidating the role of NGAL in detecting DN and understanding its mechanism can help establish it as a potential early marker for DN.

Risk of infectious diseases and cutaneous tumours in solid organ recipients: A meta-analysis of literature

AIM: To compare the risk of cutaneous infections and tumours in kidney transplant recipients with data recently published about this topic.

METHODS: In the present work, we evaluated the incidence of bacterial, fungal and viral cutaneous infectious diseases and the development of skin cancers in a cohort of 436 patients who underwent a renal transplantation. The median age at transplantation of our patients was 50 years and the median duration of the immunosuppression was of 7.2 years. Data obtained from our cohort were compared with those obtained by a systematic review of the literature of the last 20 years about the same topic.

RESULTS: Infectious diseases were the most frequent dermatological disorders that were diagnosed after transplantation, affecting about the 16.5% of patients. Herpes virus reactivation occurs in about the 35% of patients and is more common within 6 mo from transplantation, whereas when the immunosuppression is reduced, skin infections are mainly represented by Human Papilloma Virus infections and localized mycosis, such as pityriasis versicolor and superficial candidiasis. Bacterial infections were relatively rare and occur mainly in the first months after transplantation. The cumulative risk to develop skin cancer enhance significantly over the time, as consequence of long-term immunosuppressive regiments. Endogenous and exogenous risk factors, as well as the schedule of immunosuppression can play a role and justify the different incidence of skin cancer in the various series.

CONCLUSION: Skin infections and cancer, commonly diagnosed in transplanted patients, impact on survival and life-quality, justifying the realization of follow-up programs for the early diagnosis and treatment.

Meta-analysis comparing differing methods of endoscopic therapy for colorectal lesions

AIM: To compare the outcomes of endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) of colorectal lesions.

METHODS: An electronic systematic literature search of four computerized databases was performed in July 2014 identifying studies reporting the outcomes of colorectal ESD and EMR. The primary outcome measures were en-bloc resection rate, endoscopic clearance rate and lesion recurrence rate of the patients followed up. The secondary outcome was the complication rate (including bleeding, perforation and surgery post EMR or ESD rate). Statistical pooling and random effects modelling of the studies calculating risk difference, heterogeneity and assessment of bias and quality were performed.

RESULTS: Six observational studies reporting the outcomes of 1324 procedures were included. The en-bloc resection rate was 50% higher in the ESD group than in the EMR group (95%CI: 0.17-0.83, P < 0.0001, I² = 99.7%). Endoscopic clearance rates were also significantly higher in the ESD group (95%CI: -0.06-0.02, P < 0.0001, I² = 92.5%). The perforation rate was 7% higher in the ESD group than the EMR group (95%CI: 0.05-0.09, P > 0.05, I² = 41.1%) and the rate of recurrence was 50% higher in the EMR group than in the ESD group (95%CI: 0.20-0.79, P < 0.001, I² = 99.5%). Heterogeneity remained consistent when subgroup analysis of high quality studies was performed (with the exception of piecemeal resection rate), and overall effect sizes remained unchanged for all outcomes.

CONCLUSION: ESD demonstrates higher en-bloc resection rates and lower recurrence rates compared to colorectal EMR. Differences in outcomes may benefit from increased assessment through well-designed comparative studies.

Viral hepatitis: A narrative review of hepatitis A–E

Viral hepatitis continues to be a major health concern leading to hepatic decompensation ranging from acute hepatitis to cirrhosis and hepatocellular carcinoma. The hepatic and extrahepatic manifestations are not only debilitating but also associated with a significant economic burden. Over the last two decades, the field of virology has made significant breakthroughs leading to a better understanding of the pathophysiology of viral hepatitis, which in turn has led to new therapeutic options. The advent of direct-acting antiviral agents changed the landscape of hepatitis C virus (HCV) therapy, and new drugs are in the pipeline for chronic hepatitis B virus (HBV) treatment. There has also been a significant emphasis on screening and surveillance programs, widespread availability of vaccines, and linkage of care. Despite these efforts, significant gaps persist in care, and there is a pressing need for increased collaboration and teamwork across the globe to achieve a reduction of disease burden and elimination of HBV and HCV.

Gastrointestinal tumors and infectious agents: A wide field to explore

Infection is currently one of the main contributors to carcinogenesis. In fact, the International Agency for Research on Cancer has categorized eleven biological agents as group I carcinogens. It is estimated that around 16% of the 12.7 million new cancers diagnosed in 2008 were attributable to infectious agents. Although underdeveloped regions carry the highest incidence rates, about 7.4% of infection-related cancer cases occur in developed areas. Physicians are increasingly aware of the potential carcinogenic role of common virus like the Human Papilloma virus in cervical cancer, or the hepatitis B and C viruses in hepatocarcinoma. However, the carcinogenic role of several other infectious agents is less recognized. Given that gastrointestinal malignancies carry an overall poor prognosis, a better understanding of the carcinogenic mechanisms triggered by infectious agents is key to decrease the rate of cancer related deaths. Preventive measures directed to such infections would ideally impact survival. In this paper we review the main pathogenic mechanisms related to the development of gastrointestinal malignancies induced by infectious microorganisms and other pathogens which are currently under investigation.