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

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)

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

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