Helicobacter pylori CagA and VacA genotypes and gastric phenotype: a meta-analysis.
BACKGROUND
CagA+ and vacuolizing cytotoxin (VacA)-specific strains of Helicobacter pylori have been associated with different risks for developing gastric lesions. We aim to summarize a possible association between these genotypes and the risk for developing different gastric phenotypes.


METHODS
A MEDLINE database (PubMed) search was performed and a meta-analysis conducted.


RESULTS
Forty-four studies were retrieved, all with either a case-control (n=13) or cross-sectional (n=31) design, including 17 374 patients. CagA positivity was associated with an increased risk for gastric cancer [odds ratio (OR) 2.09 (95% confidence interval (CI), 1.48-2.94)] compared with that in individuals without gastric lesions [OR 2.44 (95% CI 1.27-4.70)] and in those with previously identified gastritis. In addition, there was an increased risk for peptic ulcer disease [OR 1.69 (95% CI 1.12-2.55)]. Individuals harboring the H. pylori strains VacA s1 (vs. s2), m1 (vs. m2), s1m1 (vs. s1m2), and s1m1 (vs. s2m2) had an increased risk for development of cancer [OR of 5.32 (95% CI 2.76-10.26), 2.50 (95% CI 1.67-3.750), 2.58 (95% CI 1.24-5.38), and 4.36 (95% CI 2.08-9.10), respectively]. s1m1 strains (vs. s2m2) were also associated with peptic ulcer disease [OR 2.04 (1.01-4.13)].


CONCLUSIONS
Our results indicate that individuals infected with CagA+ H. pylori strains and those infected with VacA s1 and m1 strains have an increased risk for gastric cancer. Cohort studies are welcome to integrate this information in the management of at-risk individuals such as those with precancerous cancer conditions and/or a family history of gastric cancer.
aCIDES, Medical Faculty bInstitute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto cCentro Hospitalar do Porto dPortuguese Institute of Oncology, Porto, Portugal.
Joana I
JI
Matos
Henrique A C
HA
de Sousa
Ricardo
R
Marcos-Pinto
Mário
M
Dinis-Ribeiro
D000942:Antigens, Bacterial / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D005756:Gastritis / Q000150:complications / Q000382:microbiology; D005838:Genotype; D016481:Helicobacter Infections / Q000150:complications / Q000382:microbiology*; D016480:Helicobacter pylori / Q000235:genetics* / Q000472:pathogenicity; D006801:Humans; D010437:Peptic Ulcer / Q000382:microbiology; D010641:Phenotype; D018570:Risk Assessment / Q000379:methods; D013274:Stomach Neoplasms / Q000382:microbiology; D014774:Virulence / Q000235:genetics
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C074689:VacA protein, Helicobacter pylori; C080866:cagA protein, Helicobacter pylori