Association between infections with CagA-positive or -negative strains of Helicobacter pylori and risk for gastric cancer in young adults. Research Group on Prevention of Gastric Carcinoma Among Young Adults.
OBJECTIVE
We assessed the association between infection with CagA-positive and -negative Helicobacter pylori and the risk of gastric cancer in young adults.


METHODS
CagA IgG antibodies were measured in sera of subjects participating in a case-control study in Japan. The study subjects were 103 gastric cancer patients <40 yr of age, 100 inpatients with benign diseases, and 101 screenees younger than age 43 yr.


RESULTS
Compared with the H. pylori-negative/CagA-negative (H. pylori-/CagA-) group, both the H. pylori-positive/CagA-negative (H. pylori+/CagA-) group and the H. pylori-positive/CagA-positive (H. pylori+/CagA+) groups showed elevated odds ratios for intestinal-type, diffuse-type, early, advanced, proximal, and distal gastric cancers. All the relationships were significant except for the H. pylori+/CagA- group in relation to proximal cancer. The overall odds ratios (95% confidence intervals) for gastric cancer in the H. pylori+/CagA- and the H. pylori+/CagA+ groups were 15.0 (6.4, 35.2) and 14.6 (6.7, 31.9), respectively. Between these two groups, no significant difference was observed in risks for intestinal-type, diffuse-type, early, advanced, proximal, or distal gastric cancer.


CONCLUSIONS
In those <40 yr of age, it is concluded that both CagA-positive and CagA-negative H. pylori infections are related to risks of intestinal-type, diffuse-type, early, advanced, and distal gastric cancers.
Kikuchi
S
S
Department of Epidemiology and Environmental Health, Juntendo University School of Medicine, Tokyo, Japan.
Crabtree
J E
JE
Forman
D
D
Kurosawa
M
M
D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial; D001426:Bacterial Proteins / Q000235:genetics* / Q000276:immunology; D016022:Case-Control Studies; D005260:Female; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D016481:Helicobacter Infections / Q000175:diagnosis / Q000276:immunology / Q000382:microbiology*; D016480:Helicobacter pylori / Q000235:genetics* / Q000276:immunology / Q000472:pathogenicity; D006801:Humans; D007564:Japan; D008297:Male; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D013274:Stomach Neoplasms / Q000175:diagnosis / Q000276:immunology / Q000382:microbiology*; D014774:Virulence / Q000235:genetics
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C080866:cagA protein, Helicobacter pylori