Infectious pathogens and risk of esophageal, gastric and duodenal cancers and ulcers in China: A case-cohort study.

Infection by certain pathogens is associated with cancer development. We conducted a case-cohort study of ~2500 incident cases of esophageal, gastric and duodenal cancer, and gastric and duodenal ulcer and a randomly selected subcohort of ~2000 individuals within the China Kadoorie Biobank study of >0.5 million adults. We used a bead-based multiplex serology assay to measure antibodies against 19 pathogens (total 43 antigens) in baseline plasma samples. Associations between pathogens and antigen-specific antibodies with risks of site-specific cancers and ulcers were assessed using Cox regression fitted using the Prentice pseudo-partial likelihood. Seroprevalence varied for different pathogens, from 0.7% for Hepatitis C virus (HCV) to 99.8% for Epstein-Barr virus (EBV) in the subcohort. Compared to participants seronegative for the corresponding pathogen, Helicobacter pylori seropositivity was associated with a higher risk of non-cardia (adjusted hazard ratio [HR] 2.73 [95% CI: 2.09-3.58]) and cardia (1.67 [1.18-2.38]) gastric cancer and duodenal ulcer (2.71 [1.79-4.08]). HCV was associated with a higher risk of duodenal cancer (6.23 [1.52-25.62]) and Hepatitis B virus was associated with higher risk of duodenal ulcer (1.46 [1.04-2.05]). There were some associations of antibodies again some herpesviruses and human papillomaviruses with risks of gastrointestinal cancers and ulcers but these should be interpreted with caution. This first study of multiple pathogens with risk of gastrointestinal cancers and ulcers demonstrated that several pathogens are associated with risks of gastrointestinal cancers and ulcers. This will inform future investigations into the role of infection in the etiology of these diseases.

Population-based investigation of common and deviating patterns of gastric cancer and oesophageal cancer incidence across populations and time.

BACKGROUND: The subtypes of gastric cancer (GC) and oesophageal cancer (EC) manifest distinct epidemiological profiles. Here, we aim to examine correlations in their incidence rates and to compare their temporal changes globally, both overall and by subtype. METHODS: Long-term incidence data were obtained from population-based registries available from the Cancer Incidence in Five Continents series. Variation in the occurrence of EC and GC (overall and by subtype) was assessed using the GC:EC ratio of sex-specific age-standardised rates (ASR) in 2008-2012. Average annual per cent changes were estimated to assess temporal trends during 1998-2012. RESULTS: ASRs for GC and EC varied remarkably across and within world regions. In the countries evaluated, the GC:EC ratio in men exceeded 10 in several South American countries, Algeria and Republic of Korea, while EC dominated in most sub-Saharan African countries. High rates of both cardia gastric cancer and oesophageal squamous cell carcinoma (ESCC) were observed in several Asian populations. Non-cardia gastric cancer rates correlated positively with ESCC rates (r=0.60) and negatively with EAC (r=-0.79). For the time trends, while GC incidence has been uniformly decreasing by on average 2%-3% annually over 1998-2012 in most countries, trends for EC depend strongly on histology, with several but not all countries experiencing increases in EAC and decreases in ESCC. CONCLUSIONS: Correlations between GC and EC incidence rates across populations are positive or inverse depending on the GC subsite and EC subtype. Multisite studies that include a combination of populations whose incidence rates follow and deviate from these patterns may be aetiologically informative.

Changing prevalence of chronic hepatitis B virus infection in China between 1973 and 2021: a systematic literature review and meta-analysis of 3740 studies and 231 million people.

OBJECTIVE: China concentrates a large part of the global burden of HBV infection, playing a pivotal role in achieving the WHO 2030 global hepatitis elimination target. METHODS: We searched for studies reporting HBV surface antigen (HBsAg) seroprevalence in five databases until January 2023. Eligible data were pooled using a generalised linear mixed model with random effects to obtain summary HBsAg seroprevalence. Linear regression was used to estimate annual percentage change (APC) and HBsAg prevalence in 2021. RESULTS: 3740 studies, including 231 million subjects, were meta-analysed. HBsAg seroprevalence for the general population decreased from 9.6% (95% CI 8.4 to 10.9%) in 1973-1984 to 3.0% (95% CI 2.1 to 3.9%) in 2021 (APC=-3.77; p<0.0001). Decreases were more pronounced in children <5 years (APC=-7.72; p<0.0001) and 5-18 years (-7.58; p<0.0001), than in people aged 19-59 years (-2.44; p<0.0001), whereas HBsAg seroprevalence increased in persons ≥60 years (2.84; p=0.0007). Significant decreases were observed in all six major Chinese regions, in both men (APC=-3.90; p<0.0001) and women (-1.82; p<0.0001) and in high-risk populations. An estimated 43.3 million (95% uncertainty interval 30.7-55.9) persons remained infected with HBV in China in 2021 (3.0%), with notable heterogeneity by region (<1.5% in North China to>6% in Taiwan and Hong Kong) and age (0.3%, 1.0%, 4.7% and 5.6% for <5 years, 5-18 years, 19-59 years and ≥60 years, respectively). CONCLUSIONS: China has experienced remarkable decreases in HBV infection over the last four decades, but variations in HBsAg prevalence persist in subpopulations. Ongoing prevention of HBV transmission is needed to meet HBV elimination targets by 2030. TRIAL REGISTRATION NUMBER: PROSPERO (CRD42021284217).

Estimating the Global Burden of Epstein-Barr Virus-Associated Gastric Cancer: A Systematic Review and Meta-Analysis.

BACKGROUND & AIMS: Evidence suggests that a fraction of new gastric cancer cases may be etiologically associated with Epstein-Barr virus (EBV), a known carcinogenic agent. We aimed to systematically explore the proportion of EBV-positive gastric cancer. METHODS: We did a systematic review (PROSPERO CRD42020164473) from January 1990 to August 2021. For each country and geographical region with available data, pooled prevalence and corresponding 95% confidence intervals (CIs) of EBV in gastric tumors were calculated for 3 subtypes of gastric adenocarcinoma (conventional adenocarcinoma, lymphoepithelioma-like gastric carcinoma, and remnant/stump carcinoma). For conventional adenocarcinoma, prevalence ratios (PRs) were presented for sex, Lauren's classification, gastric cancer stage, and anatomical location of the stomach. RESULTS: In 220 eligible studies including over 68,000 cases of conventional gastric adenocarcinoma, EBV prevalence in tumor cells was 7.5% (95% CI, 6.9%-8.1%) and was higher in men compared with women (PR, 2.1; 95% CI, 1.9-2.4), in diffuse type compared with intestinal type (PR, 1.3; 95% CI, 1.1-1.5), and in the proximal region compared with the distal region (PR, 2.5; 95% CI, 2.0-3.1). There was no difference in EBV prevalence by gastric cancer stage. EBV prevalence was 75.9% (95% CI, 62.8%-85.5%) among lymphoepithelioma-like gastric carcinoma and 26.3% (95% CI, 22.2%-32.0%) among remnant or stump carcinoma. CONCLUSIONS: Assuming a causal association between EBV and gastric cancer, our findings, when applied to the GLOBOCAN 2020 gastric cancer incidence, suggest that primary prevention such as the development of an effective EBV vaccine might prevent 81,000 EBV-associated gastric cancer cases worldwide annually.

Burden of Kaposi sarcoma according to HIV status: A systematic review and global analysis.

In 2020, over 34 000 cases of Kaposi sarcoma (KS) were estimated globally, all attributable to KS herpesvirus (KSHV). Prior to the HIV epidemic, KS already existed in KSHV endemic regions, notably in sub-Saharan Africa (SSA). The HIV epidemic has vastly increased the KS burden. We developed a methodology to provide global estimates of KS burden according to HIV status. A systematic review identified studies reporting HIV prevalence in consecutive KS series. Pooled estimates of HIV prevalence, by country or UN subregion, were used to calculate population-attributable fraction (PAF) and these were applied to IARC's GLOBOCAN 2020 to estimate burden and incidence of HIV-attributable and non-HIV-attributable KS. We identified 55 eligible studies, reporting HIV prevalence ranging from ≤5% to ≥95%. Approximately 80% of KS in SSA was estimated attributable to HIV, vs ~50% in the rest of the world. By applying PAFs to national GLOBOCAN estimates, an estimated 19 560 KS cases attributable to HIV were diagnosed in SSA in 2020 (~80% of the worldwide burden), vs 5064 cases of non-HIV-attributable KS (~60% of the worldwide burden). Incidence of HIV-attributable KS was highest in Southern Africa (6.0 cases per 100 000) and Eastern Africa (3.4), which were also the world regions with highest incidence of non-HIV-attributable KS (0.4 and 1.0 cases per 100 000, respectively). This first systematic effort to produce a global picture of KS burden stratified by HIV status highlights the continuing important burden of HIV-attributable KS in SSA, even in the era of combined antiretroviral therapy.

Epstein-Barr virus prevalence among subtypes of malignant lymphoma in Rwanda, 2012 to 2018.

Few data exist on Epstein-Barr virus (EBV) prevalence across the full spectrum of lymphoma subtypes, particularly in sub-Saharan Africa. The objective of our study was to test the presence of EBV in a nationally representative sample of malignant lymphomas diagnosed in the Butaro Cancer Center of Excellence (BCCOE) in Rwanda. Of 102 Hodgkin (HL) and 378 non-Hodgkin lymphomas (NHL) diagnosed in BCCOE between 2012 and 2018, 52 HL and 207 NHL were successfully tested by EBV-encoding RNA in situ hybridization. EBV prevalence was 54% in HL, being detected in all classical HL subtypes: mixed-cellularity (n = 3/8), nodular-sclerosis (n = 7/17) and lymphocyte-rich (n = 2/3). EBV prevalence was 9% in NHL, being 10% among 158 B-cell NHL, 3% among 35 T-cell NHL and the single NK-cell NHL was EBV-positive. Among B-cell NHL, EBV was present in the majority of Burkitt (n = 8/13), and was also rarely detected in follicular (n = 1/4) and acute B-cell lymphoblastic (n = 1/45) lymphomas. Five of the 45 (11%) diffuse large B-cell lymphomas (DLBCLs) were EBV-positive, including three out of five plasmablastic lymphoma (PBL). Of 39 HL and 163 NHL of known human immunodeficiency virus (HIV) status, 2 (5%) and 14 (9%) were HIV-positive, respectively, of which only four were also EBV-positive (2 PBL, 2 HL). In summary, we report rare regional-level data on the association of EBV with classical HL, Burkitt and DLBCLs, and report sporadic detection in other subtypes possibly related to EBV. Such data inform the burden of disease caused by EBV and can help guide application of future advances in EBV-specific prevention and therapeutics.

Age-specific burden of cervical cancer associated with HIV: A global analysis with a focus on sub-Saharan Africa.

HIV substantially worsens human papillomavirus (HPV) carcinogenicity and contributes to an important population excess of cervical cancer, particularly in sub-Saharan Africa (SSA). We estimated HIV- and age-stratified cervical cancer burden at a country, regional and global level in 2020. Proportions of cervical cancer (a) diagnosed in women living with HIV (WLHIV), and (b) attributable to HIV, were calculated using age-specific estimates of HIV prevalence (UNAIDS) and relative risk. These proportions were validated against empirical data and applied to age-specific cervical cancer incidence (GLOBOCAN 2020). HIV was most important in SSA, where 24.9% of cervical cancers were diagnosed in WLHIV, and 20.4% were attributable to HIV (vs 1.3% and 1.1%, respectively, in the rest of the world). In all world regions, contribution of HIV to cervical cancer was far higher in younger women (as seen also in empirical series). For example, in Southern Africa, where more than half of cervical cancers were diagnosed in WLHIV, the HIV-attributable fraction decreased from 86% in women ≤34 years to only 12% in women ≥55 years. The absolute burden of HIV-attributable cervical cancer (approximately 28 000 cases globally) also shifted toward younger women: in Southern Africa, 63% of 5341 HIV-attributable cervical cancer occurred in women <45 years old, compared to only 17% of 6901 non-HIV-attributable cervical cancer. Improved quantification of cervical cancer burden by age and HIV status can inform cervical cancer prevention efforts in SSA, including prediction of the impact of WLHIV-targeted vs general population approaches to cervical screening, and impact of HIV prevention.

Estimating the attributable fraction of cirrhosis and hepatocellular carcinoma due to hepatitis B and C.

A goal of the WHO strategy on the elimination of hepatitis as a public threat is a 65% reduction in the attributable mortality. Deaths related to hepatitis B and C infections are mostly due to decompensated cirrhosis and hepatocellular carcinoma (HCC) but accurately measuring mortality is challenging as death certificates often do not capture the underlying disease. The aim of this collaborative study between European Centre for Disease Prevention and Control (ECDC) and the European Association for the Study of the Liver (EASL) was to assess a WHO-developed protocol to support countries in implementing studies to collect data on the fraction of cirrhosis and hepatocellular carcinoma attributable to hepatitis B and C. Three sentinel sites (in Bulgaria, Norway and Portugal) collected data for patients first admitted or seen in their centres during 2016. Patients with cirrhosis or HCC were identified through patient files or healthcare databases using ICD-10 codes. The proportion of patients with cirrhosis and HCC who tested positive for HBV and HCV were calculated to estimate the aetiological fractions. After the pilot study was completed, each site was asked about the feasibility and acceptability of the protocol. A total of 1249 patients presenting with cirrhosis and/or HCC were evaluated across the three sites. The prevalence of HBV and HCV among cases of cirrhosis showed that in Norway and Portugal, HCV was responsible for about one-quarter of the cases, whereas in Bulgaria, HBV was more common. For HCC, HCV was responsible for more than one-third of cases in Norway and Portugal, while in Bulgaria HBV was more frequent as the underlying cause. Results obtained during the pilot study were comparable to published estimates obtained through statistical modelling or meta-analyses. Several challenges were reported from the sites involved in the pilot including the considerable time needed for reviewing the hospital records and extracting patient data. The pilot demonstrated the feasibility of collecting data on the prevalence of HBV and HCV infection among patients with cirrhosis and HCC in sentinel sites. This method can be used to estimate mortality attributable to HBV and HCV for elimination monitoring. Where easily implementable, sentinel studies are the best way to empower countries, get up-to date data and closely monitor the changes in the attributable fraction at a country level.

The global prevalence of hepatitis D virus infection: Systematic review and meta-analysis.

BACKGROUND AND AIMS: There are uncertainties about the epidemic patterns of HDV infection and its contribution to the burden of liver disease. We estimated the global prevalence of HDV infection and explored its contribution to the development of cirrhosis and hepatocellular carcinoma (HCC) among HBsAg-positive people. METHODS: We searched Pubmed, EMBASE and Scopus for studies reporting on total or IgG anti-HDV among HBsAg-positive people. Anti-HDV prevalence was estimated using a binomial mixed model, weighting for study quality and population size. The population attributable fraction (PAF) of HDV to cirrhosis and HCC among HBsAg-positive people was estimated using random effects models. RESULTS: We included 282 studies, comprising 376 population samples from 95 countries, which together tested 120,293 HBsAg-positive people for anti-HDV. The estimated anti-HDV prevalence was 4.5% (95% CI 3.6-5.7) among all HBsAg-positive people and 16.4% (14.6-18.6) among those attending hepatology clinics. Worldwide, 0.16% (0.11-0.25) of the general population, totalling 12.0 (8.7-18.7) million people, were estimated to be anti-HDV positive. Prevalence among HBsAg-positive people was highest in Mongolia, the Republic of Moldova and countries in Western and Middle Africa, and was higher in injecting drug users, haemodialysis recipients, men who have sex with men, commercial sex workers, and those with HCV or HIV. Among HBsAg-positive people, preliminary PAF estimates of HDV were 18% (10-26) for cirrhosis and 20% (8-33) for HCC. CONCLUSIONS: An estimated 12 million people worldwide have experienced HDV infection, with higher prevalence in certain geographic areas and populations. HDV is a significant contributor to HBV-associated liver disease. More quality data are needed to improve the precision of burden estimates. LAY SUMMARY: We combined all available studies to estimate how many people with hepatitis B also have hepatitis D, a viral infection that only affects people with hepatitis B. About 1 in 22 people with hepatitis B also have hepatitis D, increasing to 1 in 6 when considering people with liver disease. Hepatitis D may cause about 1 in 6 of the cases of cirrhosis and 1 in 5 of the cases of liver cancer that occur in people with hepatitis B. Hepatitis D is an important contributor to the global burden of liver disease.

Time trends and other sources of variation in Helicobacter pylori infection in mainland China: A systematic review and meta-analysis.

BACKGROUND: Helicobacter pylori (H pylori) is a carcinogen that causes a huge burden of gastric cancer in China. We aimed to evaluate the temporal trends and other sources of variation of H pylori infection in adults from mainland China. MATERIALS AND METHODS: For this systematic review and meta-analysis, we searched PubMed, Embase, China National Knowledge Infrastructure, and Wanfang databases for articles published from January 1983 to June 2020. We included studies reporting H pylori prevalence in adults and then applied random effect meta-analyses to obtain pooled prevalence estimates for all studies and subgroups. Sources of heterogeneity were investigated by moderator analysis, and time trends were assessed through random effect meta-regression. RESULTS: Of the 2121 studies identified, 98 were eligible for inclusion. The pooled estimate of 670 572 participants from 26 provinces during 1983-2018 was 49.6% (95% CI: 46.9%, 52.4%). H pylori prevalence varied considerably, ranging from 20.6% to 81.8%. Periods, urban/rural status, detection method, and study design explained 18.8%, 24.0%, 17.8%, and 30.4% of the heterogeneity, respectively. Overall, H pylori prevalence declined by -0.9% (95% CI: -1.1%, -0.6%) annually. Consistent declines in prevalence were observed by sex, age, and study characteristics. CONCLUSIONS: Helicobacter pylori prevalence is slowly decreasing over time in mainland China, but the low declining speed is not enough to have a major impact on gastric cancer incidence for many years. The time trends and the large heterogeneity should be taken into account when conducting regional comparisons, disease burden estimations, and customized strategy making.

Helicobacter pylori seroprevalence in six different ethnic groups living in Amsterdam: The HELIUS study.

BACKGROUND: Helicobacter pylori prevalence varies greatly worldwide. We explored the prevalence of H. pylori and CagA seropositivity among adults aged 18-44 years living in the Netherlands by ethnicity and migration status (first vs second generation). MATERIALS AND METHODS: Participants from six different ethnic groups were selected from the population-based multi-ethnic HELIUS study in Amsterdam, the Netherlands. Serum samples were tested for H. pylori antigens using a validated Luminex-based multiplex serology assay. Prevalence ratios were estimated using Poisson regression analysis. RESULTS: A total of 4683 participants aged 18-44 years were randomly selected based on sex, ethnicity, and age. H. pylori seroprevalence was highest in the Ghanaian group (84%), followed by Moroccan (81%), Turkish (66%), African Surinamese (51%), South-Asian Surinamese (48%), and Dutch (17%) participants. All ethnic minority groups had a significantly higher risk of being H. pylori seropositive compared to the Dutch group. This association was strongest among participants born outside the Netherlands (first generation), but was still significant and apparent among second-generation participants. Among first-generation participants, all groups, except the Moroccans, had a significantly higher proportion of individuals with a cagA + H. pylori strain compared to the Dutch participants. CONCLUSION: Helicobacter pylori seroprevalence among first-generation migrants is high in the Netherlands and remains elevated among second-generation migrants (ie, those born in the Netherlands). High exposure to H. pylori, and especially to the more virulent cagA+ strain, highlights the need for tailored prevention of gastric diseases (notably peptic ulcers and cancers) among migrants.

Fraction and incidence of liver cancer attributable to hepatitis B and C viruses worldwide.

High-quality data on liver cancers by probable cause are scarce in many regions of the world. The United Nations recently set a goal of eliminating viral hepatitis as a major public health threat by 2030. We aimed to estimate the number of new cases of cancers attributable to hepatitis B virus (HBV) and hepatitis C virus (HCV) at a global, regional and country level, and by development status. We used data on the prevalence of HBV and HCV in hepatocellular carcinoma from a systematic review including 119,000 cases in 260 studies covering 50 countries. A statistical model was constructed to extrapolate empirical data to countries without prevalence data. Country-specific numbers of liver cancer cases attributable to HBV and HCV were calculated using data from GLOBOCAN 2012. Globally, 770,000 cases of liver cancer occurred worldwide in 2012, of which 56% (95% CI: 52-60) were attributable to HBV and 20% (95% CI: 18-22) to HCV. Currently, HBV causes approximately two out of three cases of liver cancer in less developed countries but one in four cases in more developed countries and shows a much higher degree of geographical aggregation in Eastern Asia and sub-Saharan Africa than HCV. These estimates help set priorities for liver cancer prevention. High-coverage HBV vaccination will be transformational in HBV-endemic countries but the prevention of HCV transmission and the treatment of chronic carriers of both viruses requires new scalable solutions.

New cancer cases in France in 2015 attributable to infectious agents: a systematic review and meta-analysis.

To provide an assessment of the burden of cancer in France in 2015 attributable to infectious agents. A systematic literature review in French representative cancer cases series was undertaken of the prevalence of infectious agents with the major associated cancer types. PubMed was searched for original studies published up to September 2016; random-effects meta-analyses were performed. Cancer incidence data were obtained from the French Cancer Registries Network, thereby allowing the calculation of national incidence estimates. The number of new cancer cases attributable to infectious agents was calculated using population-attributable fractions according to published methods. Of the 352,000 new cancer cases in France in 2015, 14,336 (4.1% of all new cancer cases) were attributable to infectious agents. The largest contributors were human papillomavirus (HPV) and Helicobacter pylori, responsible for 6333 and 4406 new cancer cases (1.8 and 1.3% of all new cancer cases) respectively. Infectious agents caused a non-negligible number of new cancer cases in France in 2015. Most of these cancers were preventable. The expansion of vaccination (i.e., for hepatitis B virus and HPV) and screen-and-treat programs (for HPV and hepatitis C virus, and possibly for H. pylori) could greatly reduce this cancer burden.

Worldwide burden of cancer attributable to HPV by site, country and HPV type.

HPV is the cause of almost all cervical cancer and is responsible for a substantial fraction of other anogenital cancers and oropharyngeal cancers. Understanding the HPV-attributable cancer burden can boost programs of HPV vaccination and HPV-based cervical screening. Attributable fractions (AFs) and the relative contributions of different HPV types were derived from published studies reporting on the prevalence of transforming HPV infection in cancer tissue. Maps of age-standardized incidence rates of HPV-attributable cancers by country from GLOBOCAN 2012 data are shown separately for the cervix, other anogenital tract and head and neck cancers. The relative contribution of HPV16/18 and HPV6/11/16/18/31/33/45/52/58 was also estimated. 4.5% of all cancers worldwide (630,000 new cancer cases per year) are attributable to HPV: 8.6% in women and 0.8% in men. AF in women ranges from <3% in Australia/New Zealand and the USA to >20% in India and sub-Saharan Africa. Cervix accounts for 83% of HPV-attributable cancer, two-thirds of which occur in less developed countries. Other HPV-attributable anogenital cancer includes 8,500 vulva; 12,000 vagina; 35,000 anus (half occurring in men) and 13,000 penis. In the head and neck, HPV-attributable cancers represent 38,000 cases of which 21,000 are oropharyngeal cancers occurring in more developed countries. The relative contributions of HPV16/18 and HPV6/11/16/18/31/33/45/52/58 are 73% and 90%, respectively. Universal access to vaccination is the key to avoiding most cases of HPV-attributable cancer. The preponderant burden of HPV16/18 and the possibility of cross-protection emphasize the importance of the introduction of more affordable vaccines in less developed countries.

World-wide relative contribution of hepatitis B and C viruses in hepatocellular carcinoma.

UNLABELLED: Hepatitis B virus (HBV) and hepatitis C virus (HCV) are major causes of hepatocellular carcinoma (HCC). In order to assess the relative contribution of HBV and HCV to HCC worldwide, and identify changes over time, we conducted a systematic review of case series published up to the year 2014. Eligible studies had to report seroprevalence of both hepatitis B surface antigen (HBsAg) and antibodies to HCV (anti-HCV), alone and in combination, for at least 20 adult HCC cases. Studies using a first-generation enzyme-linked immunosorbent assay test for HCV were excluded. A total of 119,000 HCC cases in 260 studies were included from 50 countries. Most European and American countries show a preponderance of HCV over HBV and a substantial fraction of viral marker-negative cases. Asian and African countries generally show a predominance of HBV. The fraction of HCV-positive HCC cases is substantial in Taiwan, Mongolia, Japan, and Pakistan as well as in Western-Central Asia and Northern Africa. No eligible studies were available in Oceania, large parts of Africa, Eastern Europe, and Central Asia. The United States, Brazil, and Germany show evidence of higher prevalence of HCV in HCC since the year 2000. Conversely, Japan and Italy show a decline in the proportion of HCV-positive HCC. CONCLUSION: HBV and HCV are predominant causes of HCC in virtually all world areas, with a growing fraction of HCC cases in several countries attributable to HCV.

Global burden of gastric cancer attributable to Helicobacter pylori.

We previously estimated that 660,000 cases of cancer in the year 2008 were attributable to the bacterium Helicobacter pylori (H. pylori), corresponding to 5.2% of the 12.7 million total cancer cases that occurred worldwide. In recent years, evidence has accumulated that immunoblot (western blot) is more sensitive for detection of anti-H. pylori antibodies than ELISA, the detection method used in our previous analysis. The purpose of this short report is to update the attributable fraction (AF) estimate for H. pylori after briefly reviewing new evidence, and to reassess the global burden of cancer attributable to H. pylori. We therefore reviewed the literature for studies comparing the risk of developing non-cardia gastric cancer (NCGC) in cases and controls, using both ELISA and multiple antigen immunoblot for detection of H. pylori. The results from prospective studies were combined, and the new pooled estimates were applied to the calculation of the AF for H. pylori in NCGC, then to the burden of infection-related cancers worldwide. Using the immunoblot-based data, the worldwide AF for H. pylori in NCGC increased from 74.7% to 89.0%. This implies approximately 120,000 additional cases of NCGC attributable to H. pylori infection for a total of around 780,000 cases (6.2% instead of 5.2% of all cancers). These updated estimates reinforce the role of H. pylori as a major cause of cancer.

Global burden of cancers attributable to infections in 2008: a review and synthetic analysis.

BACKGROUND: Infections with certain viruses, bacteria, and parasites have been identified as strong risk factors for specific cancers. An update of their respective contribution to the global burden of cancer is warranted. METHODS: We considered infectious agents classified as carcinogenic to humans by the International Agency for Research on Cancer. We calculated their population attributable fraction worldwide and in eight geographical regions, using statistics on estimated cancer incidence in 2008. When associations were very strong, calculations were based on the prevalence of infection in cancer cases rather than in the general population. Estimates of infection prevalence and relative risk were extracted from published data. FINDINGS: Of the 12·7 million new cancer cases that occurred in 2008, the population attributable fraction (PAF) for infectious agents was 16·1%, meaning that around 2 million new cancer cases were attributable to infections. This fraction was higher in less developed countries (22·9%) than in more developed countries (7·4%), and varied from 3·3% in Australia and New Zealand to 32·7% in sub-Saharan Africa. Helicobacter pylori, hepatitis B and C viruses, and human papillomaviruses were responsible for 1·9 million cases, mainly gastric, liver, and cervix uteri cancers. In women, cervix uteri cancer accounted for about half of the infection-related burden of cancer; in men, liver and gastric cancers accounted for more than 80%. Around 30% of infection-attributable cases occur in people younger than 50 years. INTERPRETATION: Around 2 million cancer cases each year are caused by infectious agents. Application of existing public health methods for infection prevention, such as vaccination, safer injection practice, or antimicrobial treatments, could have a substantial effect on the future burden of cancer worldwide. FUNDING: Fondation Innovations en Infectiologie (FINOVI) and the Bill & Melinda Gates Foundation (BMGF).

Estimating the prevalence of Epstein-Barr virus in primary gastric lymphoma: a systematic review and meta-analysis.

The stomach is a common site for extranodal non-Hodgkin's lymphoma. While Helicobacter pylori (H. pylori) is the main established risk factor for primary gastric lymphoma, a fraction could be aetiologically associated with Epstein-Barr virus (EBV), a known haematolymphoid carcinogen. We systematically searched five databases from 1 January 1990 until 31 May 2022 for studies reporting EBV prevalence in gastric lymphoma tumour tissue by in-situ hybridisation (ISH) for EBV-encoded small RNA (PROSPERO CRD42020164473). We included representative series of more than five gastric lymphoma cases. Pooled prevalence and corresponding 95% confidence intervals (CI) of EBV in gastric tumour cells were calculated for two major gastric B-cell lymphoma types, mucosa-associated lymphoid tissue (MALT) lymphoma and diffuse large B-cell lymphoma (DLBCL). When available, we also extracted data on H. pylori prevalence and survival by EBV status. We found ten studies including 194 cases of gastric MALT lymphoma and 11 studies including 643 cases of gastric DLBCL. EBV prevalence was 2.2% (95% CI: 0.5-13.3) in gastric MALT lymphoma and 11.0% (95% CI: 5.2-20.0) in gastric DLBCL. In a subset of studies, the prevalence of H. pylori was higher in gastric MALT lymphoma (51/69) compared to gastric DLBCL (62/102). Overall, our findings suggest that EBV is rarely seen in MALT lymphoma but is associated with around 10% of gastric DLBCL, similar to the proportion observed at other primary sites. EBV-related lymphoma adds a small number of cases to the burden of cancer that could be prevented by the future development of a vaccine against EBV.

Helicobacter pylori multiplex serology and risk of non-cardia and cardia gastric cancer: a case-cohort study and meta-analysis.

BACKGROUND: Helicobacter pylori infection is a major cause of non-cardia gastric cancer (NCGC), but uncertainty remains about the associations between sero-positivity to different H. pylori antigens and risk of NCGC and cardia gastric cancer (CGC) in different populations. METHODS: A case-cohort study in China included ∼500 each of incident NCGC and CGC cases and ∼2000 subcohort participants. Sero-positivity to 12 H. pylori antigens was measured in baseline plasma samples using a multiplex assay. Hazard ratios (HRs) of NCGC and CGC for each marker were estimated using Cox regression. These were further meta-analysed with studies using same assay. RESULTS: In the subcohort, sero-positivity for 12 H. pylori antigens varied from 11.4% (HpaA) to 70.8% (CagA). Overall, 10 antigens showed significant associations with risk of NCGC (adjusted HRs: 1.33 to 4.15), and four antigens with CGC (HRs: 1.50 to 2.34). After simultaneous adjustment for other antigens, positive associations remained significant for NCGC (CagA, HP1564, HP0305) and CGC (CagA, HP1564, HyuA). Compared with CagA sero-positive only individuals, those who were positive for all three antigens had an adjusted HR of 5.59 (95% CI 4.68-6.66) for NCGC and 2.17 (95% CI 1.54-3.05) for CGC. In the meta-analysis of NCGC, the pooled relative risk for CagA was 2.96 (95% CI 2.58-3.41) [Europeans: 5.32 (95% CI 4.05-6.99); Asians: 2.41 (95% CI 2.05-2.83); Pheterogeneity<0.0001]. Similar pronounced population differences were also evident for GroEL, HP1564, HcpC and HP0305. In meta-analyses of CGC, two antigens (CagA, HP1564) were significantly associated with a higher risk in Asians but not Europeans. CONCLUSIONS: Sero-positivity to several H. pylori antigens was significantly associated with an increased risk of NCGC and CGC, with varying effects between Asian and European populations.

Global reporting of progress towards elimination of hepatitis B and hepatitis C.

BACKGROUND: The 69th World Health Assembly endorsed the global health sector strategy on viral hepatitis to eliminate viral hepatitis as a public health threat by 2030. Achieving and measuring the 2030 targets requires a substantial increase in the capacity to test and treat viral hepatitis infections and a mechanism to monitor the progress of hepatitis elimination. This study aimed to identify the gaps in data availability or quality and create a new mechanism to monitor the progress of hepatitis elimination. METHODS: In 2020, using a questionnaire, we collected empirical, systematic, modelled, or surveyed data-reported by WHO country and WHO regional offices-on indicators of progress towards elimination of viral hepatitis, including burden of infection, incidence, mortality, and the cascade of care, and validated these data. FINDINGS: WHO received officially validated country-provided data from 130 countries or territories, and used partner-provided data for 70 countries or territories. We estimated that in 2019, globally, 295·9 million (3·8%) people were living with chronic hepatitis B virus (HBV) infection and 57·8 million (0·8%) people were living with chronic hepatitis C virus (HCV) infection. Globally, there were more than 3·0 million new infections with HBV and HCV and more than 1·1 million deaths due to the viruses in 2019. In 2019, 30·4 million (95% CI 24·3-38·0) individuals living with hepatitis B knew their infection status and 6·6 million (5·3-8·3) people diagnosed with hepatitis B received treatment. Among people with HCV infection, 15·2 million (95% CI 12·1-19·0) had been diagnosed between 2015 and 2019, and 9·4 million (7·5-11·7) people diagnosed with hepatitis C infection were treated with direct-acting antiviral drugs between 2015 and 2019. INTERPRETATION: There has been notable global progress towards hepatitis elimination. In 2019, 30·4 million (10·3%) people living with hepatitis B knew their infection status, which was slightly higher than in 2015 (22·0 million; 9·0%), and 6·6 million (22·7%) of those diagnosed with hepatitis B received treatment, compared with 1·7 million (8·0%) in 2015. Mortality from hepatitis C has declined since 2019, driven by an increase in HCV treatment ten times that of the strategy baseline. However, an estimated 89·7% of HBV infections and 78·6% of HCV infections remain undiagnosed. A new global strategy for 2022-30, based on these new estimates, should be implemented urgently to scale up the screening and treatment of viral hepatitis. FUNDING: World Health Organization.