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Background: Notable geographic and temporal variations in the prevalence and genotypes of Helicobacter pylori, in relation to gastric pathologies, have been observed; however, their significance and trends in African populations is scarcely described. The aim of this study, was to investigate the association of H. pylori and its respective CagA and vacuolating cytotoxin A (VacA) genotypes with gastric adenocarcinoma, and to describe the trends of H. pylori genotypes over an 8-year period (2012-2019). Materials and methods: A total of 286 samples of gastric cancer cases and benign controls (one-to-one matching), from three main cities in Kenya, between 2012 and 2019 were included. Histologic evaluation, and CagA and VacA genotyping using PCR, was performed. Distribution of H. pylori genotypes was presented in proportions. To determine association, a univariate analysis was conducted using a Wilcoxon rank sum test for continuous variables, and a Chi-squared test or Fisher's exact test for categorical data. Results: The VacA s1m1 genotype was associated with gastric adenocarcinoma, {odds ratio (OR) = 2.68 [confidence interval (CI) of 95%: 0.83-8.65]; p = 0.108}, whilst VacA s2m2 was associated with a reduced probability of gastric adenocarcinoma [OR = 0.23 (CI 95%: 0.07-0.78); p = 0.031]. No association between cytotoxin associated gene A (CagA) and gastric adenocarcinoma was observed. Conclusion: Over the study period, an increase in all genotypes of H. pylori was seen, and although no predominant genotype was noted, there was significant year-to-year variation, with VacA s1 and VacA s2 showing the greatest variation. VacA s1m1 and VacA s2m2 were associated with increased, and reduced risk of gastric cancer, respectively. Intestinal metaplasia and atrophic gastritis did not appear to be significant in this population.
RESUMO
OBJECTIVE: To determine the frequency of the HPV associated endocervical adenocarcinomas diagnosed at a tertiary referral laboratory in Kenya over a one-year period and classify them by histologic subtypes according to the proposed criteria by IECC. MATERIALS AND METHODS: This was a collaborative cross-sectional descriptive study. Formalin-fixed parrafin embedded tissue blocks of 29 confirmed cases of endocervical adenocarcinoma diagnosed at AKUHN between July 2017 and July 2018 were analyzed for presence of 14 hrHPV subtypes including types 16 and 18 using GenomeMETM's GeneNavTm HPV One qPCR kit. Variables analyzed included age, histologic subtype and presence or absence of hrHPV. RESULTS: Twenty-nine cases were analyzed (median age=48years, range 23-70 years), of which 27(93.1%) were positive for hrHPV, with type 16 alone positive in 11(40.7%) cases and present alone or in combination with others including type 18 in 21(72.4%) cases. All hrHPV positive cases had either type 16 or 18. Twenty cases (69.0%) were classified as usual type adenocarcinoma, all positive for hrHPV. Other HPV associated adenocarcinomas identified were mucinous, signet ring cell type (4), villoglandular (2) and mucinous, NOS (1). There were only two cases of non-HPV associated adenocarcinoma. CONCLUSION: In this series, we show that the proportion of HPV associated endocervical adenocarcinoma in Kenya is high and is particularly driven by types 16 and 18. Policy makers, hospitals and laboratories in East Africa should make an effort to avail the various techniques of detecting hrHPV critical in screening and diagnosis of endocervical adenocarcinoma.