Endoscopic diagnosis of gastric and oesophageal cancer in Lusaka, Zambia: a retrospective analysis.

INTRODUCTION: There are uncertainties surrounding the spectrum of upper gastrointestinal (UGI) diseases in sub-Saharan Africa. This is mainly due to the limitations of data collection and recording. We previously reported an audit of UGI endoscopic diagnoses in Zambia spanning from 1977 to 2014. We now have extended this analysis to include subsequent years, in order to provide a more comprehensive picture of how the diagnoses have evolved over 4 decades. METHODS: We combined data collected from the endoscopy unit at the University Teaching Hospital (UTH) in Lusaka during a previous review with that collected from the beginning of 2015 to the end of 2021. Since 2015, an electronic data base of endoscopy reports at the UTH was kept. The electronic data base was composed of drop-down menus that allowed for standardised reporting of findings. Collected data were coded by two experienced endoscopists and analysed. RESULTS: In total, the analysis included 25,849 endoscopic records covering 43 years. The number of endoscopic procedures performed per year increased drastically in 2010. With the exception of the last 2 years, the proportion of normal endoscopies also increased during the time under review. In total, the number of gastric cancer (GC) cases was 658 (3%) while that of oesophageal cancer (OC) was 1168 (5%). The number of GC and OC diagnoses increased significantly over the period under review, (p < 0.001 for both). For OC the increase remained significant when analysed as a percentage of all procedures performed (p < 0.001). Gastric ulcers (GU) were diagnosed in 2095 (8%) cases, duodenal ulcers (DU) in 2276 (9%) cases and 239 (1%) had both ulcer types. DU diagnosis showed a significantly decreasing trend over each decade (p < 0.001) while GU followed an increasing trend (p < 0.001). CONCLUSIONS: UGI endoscopic findings in Lusaka, Zambia, have evolved over the past four decades with a significant increase of OC and GU diagnoses. Reasons for these observations are yet to be established

HIV infection and domestic smoke exposure, but not human papillomavirus, are risk factors for esophageal squamous cell carcinoma in Zambia: a case-control study

(c) 2015 The Authors. Cancer Medicine published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited

Prevalence of Clarithromycin-Resistant Helicobacter pylori Strains in Zambia: A Sub-Saharan African Country.

INTRODUCTION: Helicobacter pylori (H. pylori) is one of the most important infections globally, affecting more than 50% of the human population. Clarithromycin (CLA)-containing regimens are recommended for empirical eradication of H. pylori in populations with less than 15% resistance. The aim of this study was to estimate the prevalence of CLA resistance in samples collected from Zambian patients to determine if CLA is suitable for first-line H. pylori empirical treatment. METHODOLOGY: We used archival biopsy samples collected from dyspeptic patients undergoing endoscopy. The samples had been snap-frozen immediately after collection and stored at -80°C. We performed multiplex real-time PCR using Bosphore Helicobacter pylori Genotyping Kits v1, Istanbul, Turkey, to determine the presence of wild-type H. pylori and three mutations, A2142G, A2142C, and A2143G, of domain V in 23s rRNA gene. RESULTS: We tested 259 gastric biopsy samples from patients with dyspepsia, of which 136 (53%) were from females. The median age was 48 years (IQR 40-61 years). Endoscopically, most of the patients, 164 (63%), had a normal gastric mucosa. CLA resistance was found in 48 (28%) samples, with A2142G mutation in 23 (13%), A2143G mutation in 32 (18%), and double mutations A2142C and A2143G in 6 (3%). CONCLUSIONS: The presence of significant levels of CLA resistance in Zambia suggests that it should not be used as first-line empirical treatment for H. pylori infection. However, with a limitation of suitable alternatives, there is an urgent need to formulate new treatment approaches

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.Funding: wellcome Trust through SACORE, grant number WT087537MA

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 trendtowards 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 theUniversity Teaching Hospital, Lusaka, Zambia.Methods. Patients (n=52) with confirmed gastric adenocarcinoma and controls (n=94) undergoing endoscopy but with no macroscopicgastric 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 seroprevalencein cases was similar to that of the Zambian population. Smoking, regular alcohol intake, and gastric atrophy were all associated with cancerin univariate and multivariate analysis. Helicobacter pylori serology was positive in 84% of patients studied and cytotoxin-associated gene A(cagA) serology in 66%; neither serological marker was associated with cancer. Atrophy was common in cases (57%) and controls (30%) andassociated 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 commonand was not essential for the development of intestinal metaplasia, suggesting that gastric carcinogenesis in Africa does not always followthe pathway from atrophy to intestinal metaplasia to gastric carcinoma (the so-called Correa pathway)

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

Gastric Malignancy Survival in Zambia, Southern Africa: A two year follow up study

Background: Gastric cancer poses a significant global health burden. It is the second most common cause of cancer death worldwide and the ninth leading cause of cancer mortality in Zambia, at a rate of 3.8/100,000; comparable to USA (2/100,000) and UK (3.4/100,000). Survival data on gastric malignancy in Zambia is not known.Objectives: To provide preliminary survival rates of patients with histologically proven gastric adenocarcinoma in Zambia.Study Design: Using our prospective gastric cancer research database, we conducted a retrospective audit of patients diagnosed with gastric cancer at the University Teaching Hospital, Zambia, from June 2010 until January 2012. We contacted patients or their relatives using phone numbers provided at time of enrollment.Main Outcomes: We reviewed age, sex, demographic data (income, education), body mass index, symptoms, duration of symptoms, treatment (surgery, chemotherapy, radiotherapy or combination) and survival outcome.  Analysis was performed using Kaplan-Meier models and log rank test.Results: Fifty one patients were diagnosed with gastric adenocarcinoma during the study period, but follow-up data were available for 50. Median survival was 142 days. Age, sex, income, education, BMI, tumor location, and treatment modality were not significantly associated with overall survival. In Cox regression models, covariates associated with survival were a history of regular alcohol intake (HR 0.49, 95%CI 0.26,0.92; P=0.025) and intestinal type cancer histology (HR 0.40, 95%CI 0.19,0.83; P=0.01).Conclusion: Prognosis of newly diagnosed gastric cancer in Zambia is poor with significant mortality within 1 yearof diagnosis, particularly among patients with weight loss and dysphagia

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

The African Esophageal Cancer Consortium: A Call to Action.

Esophageal cancer is the eighth most common cancer worldwide and the sixth most common cause of cancer-related death; however, worldwide incidence and mortality rates do not reflect the geographic variations in the occurrence of this disease. In recent years, increased attention has been focused on the high incidence of esophageal squamous cell carcinoma (ESCC) throughout the eastern corridor of Africa, extending from Ethiopia to South Africa. Nascent investigations are underway at a number of sites throughout the region in an effort to improve our understanding of the etiology behind the high incidence of ESCC in this region. In 2017, these sites established the African Esophageal Cancer Consortium. Here, we summarize the priorities of this newly established consortium: to implement coordinated multisite investigations into etiology and identify targets for primary prevention; to address the impact of the clinical burden of ESCC via capacity building and shared resources in treatment and palliative care; and to heighten awareness of ESCC among physicians, at-risk populations, policy makers, and funding agencies.The African Esophageal Cancer Consortium is supported jointly by the International Agency for Research on Cancer and the Division of Cancer Epidemiology and Genetics of the Intramural Research Program of the National Cancer Institute