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. 2023 Feb 17:10:1119513.
doi: 10.3389/fmed.2023.1119513. eCollection 2023.

Pattern and trends of Helicobacter pylori genotypes in gastric cancer: A Kenyan 8-year study

Priscilla Njenga  1 , Allan Njau  1 , Zahir Moloo  1 , Gunturu Revathi  1 , Evariste Tshibangu  2 , Yoshio Yamaoka  2
Affiliations

Pattern and trends of Helicobacter pylori genotypes in gastric cancer: A Kenyan 8-year study

Priscilla Njenga et al. Front Med (Lausanne). .

Abstract

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.

Keywords: H. pylori (Helicobacter pylori); Kenya; gastric cancer; genotype; trends.

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Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

FIGURE 1
FIGURE 1
Distribution of Helicobacter pylori amongst the histologic types and grades of gastric adenocarcinoma. (A) All samples, (B) H. pylori positive samples, and (C) H. pylori positive samples.
FIGURE 2
FIGURE 2
Trends in the distribution of Helicobacter pylori genotypes (CagA, VacA s1, VacA s2, VacA m1, and VacA m2) from 2012 to 2019.
See this image and copyright information in PMC

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