Gastric cancer in Africa: what do we know about incidence and risk factors?

Gastric bacteria as potential biomarkers for the diagnosis of atrophic gastritis

BACKGROUND

Identification of the risk factors for atrophic gastritis (AG) and prevention of further deterioration of the gastritis are effective approaches to reduce the incidence of gastric cancer. Previous studies found that dysbiosis has been implicated in a wide range of diseases, while the role of gastric bacteria as a biomarker for AG has not been explored.

METHODS AND RESULTS

Gastric juices from cases with non-atrophic gastritis (NAG) and AG were collected for investigation of bacterial composition and function. The β-diversity of microbiota exhibited a significant reduction in AG samples compared with that in NAG samples. Differential abundance analysis revealed that a total of 23 predicted species changed their distributions; meanwhile, all obligate anaerobic bacteria with a relatively high abundance lowered their contents in AG samples. Additionally, the correlation analysis indicated a clear shift in bacterial correlation pattern between the two groups. Functional interrogation of the gastric microbiota showed that bacterial metabolisms associated with enzyme families, digestive system, and endocrine system were downregulated in AG samples. The compositional dissection of "core microbiota" exhibited that oral pathogens, including Porphyromonas gingivalis, Campylobacter gracilis, and Granulicatella elegans, were magnified in AG samples, suggesting that oral diseases may be a trigger factor for early exacerbation of gastritis. Then, the differentially expressed bacteria were used as diagnostic biomarkers for the random forest classifier model for group prediction.

CONCLUSIONS

The results showed that bacterial biomarkers could distinguish AG patients from NAG cases with an accuracy of 90% at the genus level.

Gastric Signet Ring Cell Carcinoma: A Comparative Analysis of Clinicopathologic Features

Signet ring cell carcinoma (SRC) is a distinct histological subtype of gastric carcinoma. Our aim is to investigate differential characteristics between gastric SRC and other non SRC carcinomas (nSRC). It was a retrospective study including 183 patients diagnosed with gastric carcinoma over a period of 5 years at our pathology department. We performed statistical comparison of clinicopathological features between patients with SRC and those with nSRC. 127 patients (69.4%) had nSRC, 56 had SRC (30.6%), the mean age was 56.67 ± 14.03 years. Patients with SRC were younger than those with nSRC (mean age of 49.66 versus 59.76, P = 0.030). Patients with SRC tend to have more diffuse tumors in the stomach (P = 0.005), with flat macroscopic appearance (P = 0.001). Patients with SRC present more often with pT3 tumors (P < 0.001), lymph node metastasis (P = 0.024) and perineural invasion (P = 0.003). There were no significant differences between SRC and nSRC in gender, vascular invasion or distant metastasis (P > 0.05). The median survival time was 42.82 ± 1.70 months. Patients with nSRC live longer than those with SRC, but the difference was not significant (P = 0.28). SRC is a histological subtype of gastric carcinoma with distinctive clinicopathologic features. The clinical management of patients should take into account these particular features.

Helicobacter pylori-Related Metabolic Parameters and Premalignant Gastric Mucosa Histological Lesions in Swiss Bariatric Patients

Obesity, as a major risk factor of metabolic syndrome (MetS), represents a pandemic, especially in Western societies, and is considered a risk factor for malignancies. Helicobacter pylori (Hp), is a definite carcinogen with global distribution. We aimed to investigate, for the first time in Switzerland, the main gastric mucosa premalignant histological lesions of bariatric patients in correlation with MetS components and Hp Infection (Hp-I). By reviewing retrospectively 94304 patient cases, a total of 116 eligible patients having undergone bariatric surgery were identified. The mean patient age was 48.66 years. Hp(+) patients were 24% (28/116). Presence of gastric mucosa atrophy was documented in 8/28 Hp(+) patients (29%) and (2/88) Hp(-) ones (2%) (p = 0.006). Gastric mucosa intestinal metaplasia was observed in 14/28 (50%) Hp(+) patients versus 3/88 (3.4%) of Hp(-) group (p < 0.0001). Hp(+) patients exhibited statistically higher arterial hypertension (p = 0.033). The homeostatic model of assessment insulin resistance was also statistically significantly higher for the Hp(+) group (p < 0.001). In a multivariate analysis, including arterial hypertension, gastric mucosa atrophy, and intestinal metaplasia as variables, statistical significance remained only for intestinal metaplasia (p = 0.001). In conclusion, Hp-I is associated with premalignant gastric mucosa histologic lesions and MetS components, including arterial hypertension and IR. Further large-scale prospective studies are required to confirm these findings.

Hypericin Induces Apoptosis in AGS Cell Line with No Significant Effect on Normal Cells

It is of great importance to find an effective approach that not only eliminates gastric cancer cells but also do exhibits significant side effect to normal cells. Some studies have shown the effectiveness of hypericin against cancer cells. In this study, we evaluated the anti-cancer effect of Hypericin in the treatment of gastric cancer. In this study, the AGS cell line was exposed to different concentrations of hypericin for 24 and 48 h. Evaluation of cell death was done by MTT assay. The rate of apoptosis was measured by flow cytometry assay using Annexin V/ Propidium Iodide. The expression rate of Bcl2, p53 and Bax genes was evaluated by Real-time PCR test, and immunocytochemistry (ICC) analysis and western blotting was used for further evaluation of p53. MTT assay test showed that hyepricin induces 50% cell death in the concentration of 1 (µg/mL) and 0.5 (µg/mL) at 24 h and 48 h post-treatment, respectively, however no similar effect seen on fibroblast cells. Annexin/PI test revealed that cell apoptosis after exposure to hypericin for 24 h was 74%. Real-time PCR showed that expression level of Bax, p53 and Bax genes increases and Bcl2 gene decreases in AGS cell lines after treatment by hypericin. ICC analysis and western blotting for p53 confirmed these data. The results of this study indicated that hypericin has the potential to be introduced as an effective treatment for gastric cancer. Therefore, it seems that this substance has potential to be utilized as anti-cancer drug.

Whole Genome Sequencing Reveals Virulence Potentials of Helicobacter pylori Strain KE21 Isolated from a Kenyan Patient with Gastric Signet Ring Cell Carcinoma

Helicobacter pylori (H.pylori) infection is etiologically associated with severe diseases including gastric cancer; but its pathogenicity is deeply shaped by the exceptional genomic diversification and geographic variation of the species. The clinical relevance of strains colonizing Africa is still debated. This study aimed to explore genomic features and virulence potentials of H. pylori KE21, a typical African strain isolated from a native Kenyan patient diagnosed with a gastric cancer. A high-quality circular genome assembly of 1,648,327 bp (1590 genes) obtained as a hybrid of Illumina Miseq short reads and Oxford Nanopore MinION long reads, clustered within hpAfrica1 population. This genome revealed a virulome and a mobilome encoding more than hundred features potentiating a successful colonization, persistent infection, and enhanced disease pathogenesis. Furthermore, through an experimental infection of gastric epithelial cell lines, strain KE21 showed the ability to promote interleukin-8 production and to induce cellular alterations resulting from the injection of a functional CagA oncogene protein into the cells. This study shows that strain KE21 is potentially virulent and can trigger oncogenic pathways in gastric epithelial cells. Expended genomic and clinical explorations are required to evaluate the epidemiological importance of H. pylori infection and its putative complications in the study population.

[Study of epidemiological clinical and pathological characteristics of gastric adenocarcinoma in a Moroccan population]

Stomach cancer is essentially represented by gastric adenocarcinomas. It remains one of the world's top ten causes of death with a poor prognosis. The aim of our work is to describe the epidemiological characteristics of gastric adenocarcinoma through a retrospective, observational study over a period of one year. One hundred and twenty one cases were sent to the Pathology Laboratory of the IPM-Casablanca, 98 were selected for this study. There was a male predominance. Patients aged over 50 years represented the predominant age group (62%) (P-value=0.03). The average tumor size was 5,17±2,16cm, and most patients were diagnosed in the advanced TNM stage with a rate of 72.44%. In the absence of specific symptoms, gastric adenocarcinoma is a cancer of elderly, frequently diagnosed at a late stage, minimizing the chances of any curable treatment. The adoption of a screening policy in our area would probably be beneficial. Indeed, the benefit of annual screening at least among people aged over 50 years should be assessed.

Biomass Smoke Exposure Is Associated With Gastric Cancer and Probably Mediated Via Oxidative Stress and DNA Damage: A Case-Control Study

PURPOSE

We investigated the association between gastric cancer and environmental and dietary exposures. In addition, we explored probable mechanistic pathways for the influence of biomass smoke on gastric carcinogenesis.

PATIENTS AND METHODS

The study was conducted in Lusaka, Zambia. Questionnaires were used to collect data on risk factors, whereas enzyme-linked immunosorbent assays and high-performance liquid chromatography were used to measure biologic exposures. Study data were analyzed using contingency tables and logistic regression.

RESULTS

We enrolled 72 patients with gastric adenocarcinoma and 244 controls. Gastric cancer was positively associated with rural residence (odds ratio [OR], 2.9; 95% CI, 1.5 to 5.3), poverty (OR, 4.2; 95% CI, 1.9 to 9.1), and daily consumption of processed meat (OR, 6.4; 95% CI, 1.3 to 32) and negatively associated with consumption of green vegetables (OR, 0.2; 95% CI, 0.1 to 0.5). Gastric cancer was also associated with biomass smoke exposure (OR, 3.5; 95% CI, 1.9 to 6.2; P < .0001), an association that was stronger for intestinal-type cancers (OR, 3.6; 95% CI, 1.5 to 9.1; P = .003). Exposure to biomass smoke in controls was associated with higher urinary levels of 8-isoprostane (P < .0001), 8-hydroxydeoxyguanosine (P = .029), and 1-hydroxypyrene (P = .041). Gastric cancer was not associated with biochemical measures of current exposure to aflatoxins or ochratoxins.

CONCLUSION

In Zambia, exposure to biomass smoke, daily consumption of processed meat, and poverty are risk factors for gastric cancer, whereas daily consumption of green vegetables is protective against gastric cancer. Exposure to biomass smoke was associated with evidence of oxidative stress and DNA damage, suggesting mechanistic plausibility for the observed association, and the association was restricted to intestinal-type gastric cancer.

The state of cancer in Meru, Kenya: a retrospective study

Background: It is projected that by 2030, 70% of all cancer related deaths will occur in low-middle income countries. However, data on the state of cancer in most African countries is scanty. Cancer estimates for Kenya are based on the Nairobi and Eldoret cancer registries, leaving most parts of the country unrepresented. Lacking national coverage, these data do not accurately reflect Kenya’s cancer burden. The paucity of reliable data impedes formulation of effective cancer control strategies and cancer research prioritization. Here, we report the findings of a retrospective study of the cancer state in Meru County, Kenya. Methods: A retrospective analysis of patient files at Meru hospice was carried out. 2349 cancer cases seen at the Meru hospice between 2003 and 2018 were analyzed. Data abstracted from the records included patient age, gender and cancer type. The abstracted data was analyzed by descriptive statistics. Results: Our results indicate that cancer is almost evenly distributed across genders, with men accounting for 49% and women 51%. Stomach cancer rates are strikingly elevated and equal to those in countries with the highest stomach cancer rates globally – making it the commonest cancer in this region (14%). Among men, the most common cancers affect the prostate (18%), stomach (17%), esophagus (14%), head & neck (12%), liver (8%) and colorectum (5%). Among women, the commonest are cancers of the breast (22%), cervix (20%), stomach (11%), esophagus (8%), head & neck (6%) and liver (5%). Breast cancer occurs at a notably early age, with 20% of those affected aged below 40. Lung cancer rates are notably low in this region (1.3%) relative to world estimates. Conclusion: Cancer distribution in Meru is nearly even between sexes. Our analysis suggests that the Meru region is a stomach cancer hotspot and that it also experiences elevated esophageal cancer levels.

Gastro-duodenal disease in Africa: Literature review and clinical data from Accra, Ghana

Gastroduodenal disease (GDD) was initially thought to be uncommon in Africa. Amongst others, lack of access to optimal health infrastructure and suspicion of conventional medicine resulted in the reported prevalence of GDD being significantly lower than that in other areas of the world. Following the increasing availability of flexible upper gastro-intestinal endoscopy, it has now become apparent that GDD, especially peptic ulcer disease (PUD), is prevalent across the continent of Africa. Recognised risk factors for gastric cancer (GCA) include Helicobater pylori (H. pylori), diet, Epstein-Barr virus infection and industrial chemical exposure, while those for PUD are H. pylori, non-steroidal anti-inflammatory drug (NSAID)-use, smoking and alcohol consumption. Of these, H. pylori is generally accepted to be causally related to the development of atrophic gastritis (AG), intestinal metaplasia (IM), PUD and distal GCA. Here, we perform a systematic review of the patterns of GDD across Africa obtained with endoscopy, and complement the analysis with new data obtained on pre-malignant gastric his-topathological lesions in Accra, Ghana which was compared with previous data from Maputo, Mozambique. As there is a general lack of structured cohort studies in Africa, we also considered endoscopy-based hospital or tertiary centre studies of symptomatic individuals. In Africa, there is considerable heterogeneity in the prevalence of PUD with no clear geographical patterns. Furthermore, there are differences in PUD within-country despite universally endemic H. pylori infection. PUD is not uncommon in Africa. Most of the African tertiary-centre studies had higher prevalence of PUD when compared with similar studies in western countries. An additional intriguing observation is a recent, ongoing decline in PUD in some African countries where H. pylori infection is still high. One possible reason for the high, sustained prevalence of PUD may be the significant use of NSAIDs in local or over-the-counter preparations. The prevalence of AG and IM, were similar or modestly higher over rates in western countries but lower than those seen in Asia. . In our new data, sampling of 136 patients in Accra detected evidence of pre-malignant lesions (AG and/or IM) in 20 individuals (14.7%). Likewise, the prevalence of pre-malignant lesions, in a sample of 109 patients from Maputo, were 8.3% AG and 8.3% IM. While H. pylori is endemic in Africa, the observed prevalence for GCA is rather low. However, cancer data is drawn from country cancer registries that are not comprehensive due to considerable variation in the availability of efficient local cancer reporting systems, diagnostic health facilities and expertise. Validation of cases and their source as well as specificity of outcome definitions are not explicit in most studies further contributing to uncertainty about the precise incidence rates of GCA on the continent. We conclude that evidence is still lacking to support (or not) the African enigma theory due to inconsistencies in the data that indicate a particularly low incidence of GDD in African countries.

Infections with Helicobacter pylori and challenges encountered in Africa

Helicobacter pylori (H. pylori) is the causative agent of gastritis, peptic ulcer disease, mucosa associated lymphoid tissue lymphoma and gastric cancer (GC). While this bacterium infects 50% of the world’s population, in Africa its prevalence reach as high as 80% as the infection is acquired during childhood. Risk factors for H. pylori acquisition have been reported to be mainly due to overcrowding, to have infected siblings or parent and to unsafe water sources. Despite this high H. pylori prevalence there still does not exist an African guideline, equivalent to the Maastricht V/Florence Consensus Report of the European Helicobacter and Microbiota Study Group for the management of this infection. In this continent, although there is a paucity of epidemiologic data, a contrast between the high prevalence of H. pylori infection and the low incidence of GC has been reported. This phenomenon is the so-called “African Enigma” and it has been hypothesized that it could be explained by environmental, dietary and genetic factors. A heterogeneity of data both on diagnosis and on therapy have been published. In this context, it is evident that in several African countries the increasing rate of bacterial resistance, mainly to metronidazole and clarithromycin, requires continental guidelines to recommend the appropriate management of H. pylori. The aim of this manuscript is to review current literature on H. pylori infection in Africa, in terms of prevalence, risk factors, impact on human health, treatment and challenges encountered so as to proffer possible solutions to reduce H. pylori transmission in this continent.

Impact of delayed care on surgical management of patients with gastric cancer in a low-resource setting

BACKGROUND

Gastric cancer is the fifth most common cancer in Eastern Africa. Diagnostic delays in low-resource countries result in advanced disease presentation. We describe perioperative management of gastric cancer in Rwanda.

METHODS

A retrospective review of records at three hospitals was performed to identify gastric adenocarcinoma cases from January 2012 to June 2016. Multiple perioperative and tumor-related variables were collected. Descriptive and bivariate analyses were performed.

RESULTS

The final analysis included 229 patients with gastric cancer. Median age was 58 years (interquartile range [IQR] 49-65) and 49.6% were female (n = 114). Patients reported symptoms (ie, weight loss, epigastric pain) for a median time of 12 months (IQR 7.5-24). On presentation, 18.8% ( n = 43) had gastric outlet obstruction; 13.5% ( n = 31) had a palpable mass. Fifty-one percent ( n = 117) underwent an operation; of these, 74% ( n = 86) received gastrojejunostomy or were inoperable; and 29% ( n = 34) underwent curative resection. Palliative care referrals were made for 9% ( n = 20). Pathology reports were available for 190 patients (83.0%). Only 11.3% ( n = 26) had Helicobacter pylori ( H. pylori) testing of which 65.4% tested positive ( n = 17).

CONCLUSIONS

A majority of patients presented with advanced disease. Very few patients had a curative resection. Significant advances in diagnosis and treatment are needed to improve the care of gastric cancer patients in Rwanda.

Risk Factors for Gastric Cancer: A Systematic Review

Objective: Gastric cancer is one of the leading causes of death worldwide, with many influences contributing to the disease. The aim of this study was to identify the most important risk factors. Methods: This study was conducted in 2017 with a structured overview in the Science Directe, Scopus, PubMed, Cochrane, Web of Science (ISI) databases. In the first step, articles were extracted based on their titles and abstracts; the quality of 43 articles was evaluated using the STORBE tool. Inclusion criteria were studies carried out on human, English language (first step), year of the study and the study type (second step). Results: Finally, 1,381 articles were found, of which 1,269 were excluded in primary and secondary screening. In reviewing the references of the remaining 44 papers, 4 studies were added. Finally, 43 articles were selected for the quality assessment process. A total of 52 risk factors for gastric cancer were identified and classified into nine important categories: diet, lifestyle, genetic predisposition, family history, treatment and medical conditions, infections, demographic characteristics, occupational exposures and ionizing radiation’. Conclusion: Several environmental and genetic factors are involved in the development of gastric cancer. Regarding the role of changes in ‘diet and lifestyle’, considering appropriate nutrition and improving the level of education and awareness of people is vital for early diagnosis and timely treatment of this disease, especially in people with a family history and genetic predisposition.

Sero-prevalence and associated factors of Helicobacter pylori infection among adult patients with dyspepsia attending the gastroenterology unit in a tertiary hospital in Mwanza, Tanzania

BACKGROUND

Prevalence of H.pylori infection varies greatly between populations in different countries. This study was conducted to determine the magnitude of H.pylori among adult patients with dyspepsia attending the gastroenterology unit at Bugando medical centre.

METHODS

A cross sectional study involving 202 dyspeptic patients was conducted between June and July 2014. A Standardized data collection tool was used to collect socio-demographic characteristics. H.pylori antibodies were detected using rapid immunochromatographic tests according to manufacturer's instructions.

RESULTS

The median age of study population was 42 (IQR: 33-54). Females 105 (51.9%) formed majority of the population studied. Of 202 participants; 119 (58.9%) were from rural areas. Seroprevalence of H.pylori infection was found to be 79/202 (39.1%, 95% CI: 32.3-45.7). As the age increased the risk of having H.pylori infection also increased (OR: 1.02 95% CI: 1-1.04, P=0.02). On multivariate logistic regression analysis untreated drinking water was found to predict H.pylori seropositivity (OR: 2.33, CI: 1.09-4.96, p=0.028).

CONCLUSION

The seroprevalence of H.pylori among dyspeptic patients is high in this setting. Therefore the community in Mwanza should be educated on the use of safe drinking water in order to minimize H. pylori infections.

Effect of Static Magnetic Field on Oxidant/Antioxidant Parameters in Cancerous and Noncancerous Human Gastric Tissues

Aim. To investigate the effects of static magnetic field (SMF) on oxidant and antioxidant parameters of the cancerous and noncancerous human gastric tissues. Materials and Methods. Gastric tissues obtained from patients with gastric cancer were used in the study. SMF was created by using two static magnets. Before and after treatment with SMF, oxidant and antioxidant parameters were measured in the tissue samples. Results. In the cancerous tissue, superoxide dismutase (SOD) activity was found higher and malondialdehyde (MDA) level was found lower as compared with noncancerous tissue. SMF affects oxidant/antioxidant parameters differently in the cancerous and noncancerous tissues. In this regard, SMF causes increase in SOD activity and decrease in MDA level in the noncancerous tissue. However, it decreases SOD and glutathione peroxidase (GSH-Px) activities and increases MDA level and catalase (CAT) activity in the cancerous tissue. There were no differences between nitric oxide (NO) and nitric oxide synthase (NOS) parameters in or among the cancerous and noncancerous tissues. Conclusions. SMF accelerates peroxidation reactions possibly by suppressing SOD and GSH-Px enzymes in the cancerous gastric tissue. This event caused by SMF might play part in the death of cancer cells, which may be a good supportive vehicle for the cancer therapy.

Serological response to Epstein-Barr virus early antigen is associated with gastric cancer and human immunodeficiency virus infection in Zambian adults: a case-control study

INTRODUCTION

Gastric cancer is one of the major causes of cancer related deaths, but data from sub-Saharan Africa are very scanty. The cancer genome atlas (TCGA) initiative confirmed Epstein-Barr virus (EBV) related cancer as a distinct subtype, and we set out to look for serological evidence of its role in a sub-Saharan African patient group.

METHODS

We used stored serum samples obtained from a gastric cancer case-control study conducted between 2010 and 2012 in Lusaka, Zambia. A total of 147 patients were included with 51 gastric adenocarcinoma cases and 96 age and sex matched controls. The presence of antibodies to EBV nuclear antigen-1 (EBNA-1) and early antigen (EA) was determined using commercially available ELISA kits. Data were analysed in STATA Stata Corp, College Station TX.

RESULTS

Over 90% of all the samples analysed were positive for antibodies to EBNA-1. The presence of antibodies to EBV EA was significantly higher in gastric cancer cases than in controls, (OR 4.38; 95% CI 1.53-13.06, P = 0.0027), with an attributable risk of 23%. HIV infection was also associated with EBV EA seroprevalence (OR 10.97; 95% CI 2.26 -13.06, P = 0.001) but not EBNA-1 (OR 0.81; 95% CI 0.10 -38.75, P = 0.596). There was no association of EBV infection with age below 45 years, Helicobacter pylori infection, intestinal metaplasia, gastric atrophy or inflammation.

CONCLUSION

We therefore conclude that EBV exposure is common among Zambian adults and that EBV EA seropositivity is associated with gastric cancer and HIV infection, but not premalignant lesions.

Trends in upper gastrointestinal diagnosis over four decades in Lusaka, Zambia: a retrospective analysis of endoscopic findings

Background and aims

There a shortage of robust information about profiles of gastrointestinal disease in sub-Saharan Africa. The endoscopy unit of the University Teaching Hospital in Lusaka has been running without interruption since 1977 and this 38-year record is largely intact. We report an analysis of endoscopic findings over this period.

Methods

Written endoscopy records from 29th September 1977 to 16th December 2014 were recovered, computerised, coded by two experienced endoscopists and analysed. Temporal trends were analysed using tables, graphs, and unconditional logistic regression, with age, sex of patient, decade, and endoscopist as independent variables to adjust for inter-observer variation.

Results

Sixteen thousand nine hundred fifty-three records were identified and analysed. Diagnosis of gastric ulcer rose by 22 %, and that of duodenal ulcer fell by 14 % per decade. Endoscopically diagnosed oesophageal cancer increased by 32 % per decade, but gastric cancer rose only in patients under 60 years of age (21 % per decade). Oesophageal varices were the commonest finding in patients presenting with haematemesis, increasing by 14 % per decade in that patient group. Two HIV-related diagnoses, oesophageal candidiasis and Kaposi’s sarcoma, rose from almost zero to very high levels in the 1990s but fell substantially after 2005 when anti-retroviral therapy became widely available.

Conclusions

This useful dataset suggests that there are important trends in some endoscopic findings over four decades. These trends are not explained by inter-observer variation. Reasons for the divergent trends in incidence of peptic ulceration and apparent trends in diagnosis of upper gastrointestinal cancers merit further exploration.

Noncommunicable diseases in HIV infection in low- and middle-income countries: gastrointestinal, hepatic, and nutritional aspects

The purpose of this review was to outline the interaction between HIV and noncommunicable diseases affecting the gastrointestinal (GI) tract, liver, and nutritional disorders in low- and middle-income countries (LMICs), and to identify research priorities. Noncommunicable GI tract disorders are only moderately influenced by HIV, and peptic ulceration is actually less common. However, the impact of HIV on GI cancers needs further investigation. HIV interacts strongly with environmental enteropathy, exacerbating malabsorption of nutrients and drugs. HIV has 2 major effects on noncommunicable liver disease: drug-induced liver injury and nonalcoholic fatty liver disease (particularly in persons of African genetic descent). The effect of HIV on nutrition was one of the first markers of the epidemic in the 1980s, and HIV continues to have major nutritional consequences. Childhood malnutrition and HIV frequently coexist in some regions, for example, southern Africa, resulting in powerful negative interactions with poorer responses to standard nutritional rehabilitation. HIV and nutritional care need to be better integrated, but many questions on how best to do this remain unanswered. Across the spectrum of GI, hepatic, and nutritional disorders in HIV infection, there is increasing evidence that the microbiome may play an important role in disease pathogenesis, but work in this area, especially in low- and middle-income countries, is in its infancy.

Gastric cancer in Africa: Current management and outcomes

Gastric cancer is the fourth most common cancer and second most common cause of cancer death worldwide. Globally, gastric cancer poses a significant public health burden - both economically and socially. In 2008, the economic burden from premature cancer deaths and disability was $895 billion and gastric cancer was the second highest cancer responsible for healthy life lost. With the expected increase in cancer deaths and non-communicable diseases, these costs are expected to rise and impact patient care. World Health Organization, estimates a 15% increase in non-communicable disease worldwide, with more than 20% increase occurring in Africa between 2010 and 2020. Mali, West Africa, is ranked 15^th highest incidence of gastric cancer worldwide at a rate of 20.3/100000, yet very scarce published data evaluating etiology, prevention or management exist. It is understood that risk factors of gastric cancer are multifactorial and include infectious agents (Helicobacter pylori, Epstein-Barr virus), genetic, dietary, and environmental factors (alcohol, smoking). Interestingly, African patients with gastric cancer are younger, in their 3^rd-4^th decade, and present at a late stage of the disease. There is sparse data regarding gastric cancer in Africa due to lack of data collection and under-reporting, which impacts incidence and mortality rates. Currently, GLOBOCAN, an International Agency for Research on Cancer resource, is the most comprehensive available resource allowing comparison between nations. In resource limited settings, with already restricted healthcare funding, data is needed to establish programs in Africa that increase gastric cancer awareness, curtail the economic burden, and improve patient management and survival outcomes.

Helicobacter pylori status and associated gastroscopic diagnoses in a tertiary hospital endoscopy population in Rwanda

BACKGROUND

The study was undertaken to document the prevalence of Helicobacter pylori and endoscopic diagnoses in Rwandans presenting for gastroscopy.

METHODS

We studied an endoscopic database containing 961 consecutive gastroscopy patients at the University Teaching Hospital, Butare, over 12 months. Patient characteristics, endoscopic diagnoses and H. pylori status (by modified rapid urease testing) were analysed.

RESULTS AND CONCLUSION

The overall H. pylori positivity rate was 75% (n=825), similar to that found elsewhere in sub-Saharan Africa. Common endoscopic diagnoses included duodenal ulceration (20%), duodenitis (9%), benign gastric outlet obstruction (6%) and malignancy (5%). Duodenal ulceration was strongly associated with H. pylori infection (OR 6.2 [3.1-12.6]; p<0.001).

[Epidemiology of gastric cancer: experience of a Moroccan hospital]

Le cancer de l'estomac est représenté essentiellement par Les adénocarcinomes gastriques, ces derniers demeurent l'une des dix premières causes mondiales de mortalité avec un pronostic qui est péjoratif. Son incidence reste variable à travers le monde, elle est caractérisée par une importante disparité géographique. Le but de notre travail est de décrire les caractéristiques épidémiologiques de l'adénocarcinome gastrique dans notre contexte à travers une étude rétrospective, observationnelle étalée sur une période de 10 ans (Janvier 2001- Janvier 2011), incluant tous les malades admis au service d'hépato-gastroentérologie du CHU Hassan II de Fès pour prise en charge d'un adénocarcinome gastrique. Durant cette période, 343 patients étaient admis pour prise en charge d'une tumeur gastrique, dont 170 patients avaient un adénocarcinome gastrique (49.5%). L’âge moyen de ces patients était de 58±13.4 ans [16 ans-0 ans]. Dans 43.7% des cas, les patients provenaient de la région de Fès, souvent du milieu rurale. On note une nette prédominance masculine, avec une différence significative entre les 2 sexes (p < ;0.05). Les patients âgés de moins de 60ans représentaient la tranche d’âge prédominante (63%) par rapports aux patients âgés de plus de 60ans (p = 0.02). 61% des patients consultaient dans un délai allant de 1 mois à 6 mois, 30.4% des patients étaient tabagiques, ce facteur avait une relation statistiquement significative avec l'adénocarcinome gastrique (p = 0.02). la non consommation de l'alcool est inversement liée et de façon significative à l'apparition de l'adénocarcinome gastrique (p = 0.03) dans notre contexte. L'infection par Hélicobacter pylori n’était mentionnée que chez peu de malades. Les formes métastatiques au moment du diagnostic dépassaient 50% avec un taux de décès au cours de l'hospitalisation de 2.6%. Sur le plan endoscopique, la localisation antropylorique, et la forme ulcéro-végétante étaient prédominantes, elles présentaient successivement 49% (p = 0,002) et 66% (p = 0.00001). Une chirurgie curative n’était proposée que chez 50 patients (30.2%). L'adénocarcinome gastrique représente le type histologique le plus fréquent, son pronostic reste fâcheux dans notre région, touchant une population jeune, minimisant ainsi les chances de tout traitement curatif.

NAD(P)H: quinone oxidoreductase 1 (NQO1) C609T gene polymorphism association with digestive tract cancer: a meta-analysis

NAD(P)H: quinone oxidoreductase 1 (NQO1) C609T gene polymorphisms have been reported to influence the risk for digestive tract cancer (DTC) in many studies; however, the results remain controversial and ambiguous. We therefore carried out a meta-analysis of published case-control studies to derive a more precise estimation of any associations. Electronic searches were conducted on links between this variant and DTC in several databases through April 2012. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to estimate the strength of associations in fixed or random effect models. Heterogeneity and publication bias were also assessed. A total of 21 case-control studies were identified, including 6,198 cases and 7,583 controls. Overall, there was a statistically significant association between the NQO1 C609T polymorphism and DTC risk (TT vs. CC: OR=1.224, 95%CI=1.055-1.421; TT/CT vs. CC: OR=1.195, 95%CI=1.073-1.330; TT vs. CT/CC: OR=1.183, 95%CI=1.029-1.359; T vs. C: OR=1.180, 95%CI=1.080-1.290). When stratified for tumor location, the results based on all studies showed the variant allele 609T might have a significantly increased risk of upper digest tract cancer (UGIC), but not colorectal cancer. In the subgroup analysis by ethnicity, we observed a significantly risk for DTC in Caucasians. For esophageal and gastric cancer, a significantly risk was found in both populations, and for colorectal, a weak risk was observed in Caucasians, but not Asians. This meta-analysis suggested that the NQO1 C609T polymorphism may increase the risk of DTC, especially in the upper gastric tract.

Treatment of cancer in sub-Saharan Africa

Cancer is rapidly becoming a public health crisis in low-income and middle-income countries. In sub-Saharan Africa, patients often present with advanced disease. Little health-care infrastructure exists, and few personnel are available for the care of patients. Surgeons are often central to cancer care in the region, since they can be the only physician a patient sees for diagnosis, treatment (including chemotherapy), and palliative care. Poor access to surgical care is a major impediment to cancer care in sub-Saharan Africa. Additional obstacles include the cost of oncological care, poor infrastructure, and the scarcity of medical oncologists, pathologists, radiation oncologists, and other health-care workers who are needed for cancer care. We describe treatment options for patients with cancer in sub-Saharan Africa, with a focus on the role of surgery in relation to medical and radiation oncology, and argue that surgery must be included in public health efforts to improve cancer care in the region.

Gastric cancer in Zambian adults: a prospective case-control study that assessed dietary intake and antioxidant status by using urinary isoprostane excretion

BACKGROUND

Gastric cancer is increasingly recognized in Zambia. Although nutritional factors contribute to gastric cancer risk, their effect in Zambia is unknown.

OBJECTIVE

The objective was to investigate the association between intake of dietary antioxidants, urinary 8-iso prostaglandin F2α (8-iso PGF2α) as a marker of oxidative stress, and gastric cancer.

DESIGN

This was a case-control study at the University Teaching Hospital in Zambia. Gastric cancer cases were compared with age- and sex-matched controls. Urine 8-iso PGF2α was measured primarily by ELISA, and by gas chromatography-mass spectrometry in a subset, expressed as a ratio to creatinine. Blood was collected for Helicobacter pylori, HIV serology, gastrin-17, and pepsinogen 1 and 2 concentrations. Clinical and dietary data were collected by using questionnaires. Food items were broadly classified into 7 major categories (fruit, vegetables, fish, meat, insects, cereals, and starches).

RESULTS

Fifty cases with gastric cancer (mean age: 61 y; n = 31 males) and 90 controls (mean age: 54 y; n = 41 males) were enrolled. Median urinary 8-iso PGF2α excretion was higher in cases (0.014; IQR: 0.008-0.021) than in controls (0.011; IQR: 0.006-0.018; P = 0.039). On univariate analysis, habitual fruit intake was lower in cases than in controls during the dry season (P = 0.02). On multivariate analysis, smoking (OR: 7.22; IQR: 1.38-37.9) and gastric atrophy (OR: 2.43; IQR: 1.12-5.13) were independently associated with cancer, and higher fruit intake was protective (OR: 0.44; IQR: 0.20-0.95). Isoprostane excretion was inversely correlated with total fruit intake (ρ = -0.23; n = 140; P = 0.006).

CONCLUSION

Urinary 8-iso PGF2α excretion was associated with the risk of gastric cancer, as were smoking and gastric atrophy, but increased fruit intake conferred protection. This trial was registered at www.pactr.org as ISRCTN52971746.

Gastric adenocarcinoma in Zambia: a case-control study of HIV, lifestyle risk factors, and biomarkers of pathogenesis

BACKGROUND

Gastric cancer is a leading cause of cancer deaths worldwide but there are few data from Africa. We recently observed a trend towards diagnosis in younger patients.

OBJECTIVE

To test the hypothesis that HIV might have altered risk factors for acquisition of gastric cancer, in a case-control study in the University Teaching Hospital, Lusaka, Zambia.

METHODS

Patients (n=52) with confirmed gastric adenocarcinoma and controls (n=94) undergoing endoscopy but with no macroscopic gastric pathology. Established risk factors and HIV status were compared.

RESULTS

HIV status did not differ significantly between cases and controls (odds ratio 1.03; 95% CI 0.2 - 4.3; p=1.00) and seroprevalence in cases was similar to that of the Zambian population. Smoking, regular alcohol intake, and gastric atrophy were all associated with cancer in univariate and multivariate analysis. Helicobacter pylori serology was positive in 84% of patients studied and cagA serology in 66%; neither serological marker was associated with cancer. Atrophy was common in cases (57%) and controls (30%) and associated with both smoking and alcohol use. Intestinal metaplasia was present in 17% of the controls, but was not associated with atrophy.

CONCLUSIONS

HIV was not associated with gastric cancer and does not explain the apparent younger age distribution. Atrophy was common and was not essential for the development of intestinal metaplasia, suggesting that gastric carcinogenesis in Africa does not always follow the pathway from atrophy to intestinal metaplasia to gastric carcinoma (the so-called Correa pathway).

Can the incidence of gastric cancer be reduced in the new century?

Gastric cancer (GC) is one of the most common cancers in the world. The incidence and mortality rate of GC vary among different countries. It is suggested that GC is the result of the interaction between Helicobacter pylori (H. pylori) infection and the genetic and environmental factors in the host. H. pylori infection is the trigger of intestinal gastric adenocarcinoma. The incidence of GC is highest in East Asia and East Europe, but much lower in Africa; however, H. pylori infection is commonly seen in Africa, which is known as the African enigma. The 5-year survival of early GC is far better than that of advanced GC. A high detection rate of early GC could help us to conquer GC. A decreasing trend of GC incidence has been witnessed worldwide. With the improvement of living conditions and the achievements of scientific research, it seems possible that there will be a further reduction in the incidence of GC in the new century.

Advances in gastric cancer prevention

Gastric cancer is a multifactorial neoplastic pathology numbering among its causes both environmental and genetic predisposing factors. It is mainly diffused in South America and South-East Asia, where it shows the highest morbility percentages and it is relatively scarcely diffused in Western countries and North America. Although molecular mechanisms leading to gastric cancer development are only partially known, three main causes are well characterized: Helicobacter pylori (H. pylori) infection, diet rich in salted and/or smoked food and red meat, and epithelial cadherin (E-cadherin) mutations. Unhealthy diet and H. pylori infection are able to induce in stomach cancer cells genotypic and phenotypic transformation, but their effects may be crossed by a diet rich in vegetables and fresh fruits. Various authors have recently focused their attention on the importance of a well balanced diet, suggesting a necessary dietary education starting from childhood. A constant surveillance will be necessary in people carrying E-cadherin mutations, since they are highly prone in developing gastric cancer, also within the inner stomach layers. Above all in the United States, several carriers decided to undergo a gastrectomy, preferring changing their lifestyle than living with the awareness of the development of a possible gastric cancer. This kind of choice is strictly personal, hence a decision cannot be suggested within the clinical management. Here we summarize the key points of gastric cancer prevention analyzing possible strategies referred to the different predisposing factors. We will discuss about the effects of diet, H. pylori infection and E-cadherin mutations and how each of them can be handled.