Helicobacter pylori infection and the risk of gastric malignancy.
OBJECTIVE
This prospective cohort study investigated the impact of Helicobacter pylori infection on the development of various gastric malignancies.


METHODS
We prospectively followed up 1,225 dyspeptic Taiwanese who had nonulcer dyspepsia, gastric ulcers, or duodenal ulcers at enrollment. Among them, 618 (50.4%) had H. pylori infection and 607 (49.6%) did not. Patients underwent endoscopy at enrollment and at 1- to 3-yr intervals thereafter.


RESULTS
During a mean follow-up of 6.3 yr, gastric adenocarcinoma developed in 7 of the 618 H. pylori-infected patients, but in none of the 607 uninfected patients (1.1%vs 0.0%, P= 0.015). The incidence of gastric lymphoma was 0.2% (1/618) and 0% in H. pylori-infected and uninfected patients. Taken together, the development rate of gastric malignancy in H. pylori-infected patients was significantly higher than that in uninfected patients (1.3%vs 0%, P= 0.007). Among H. pylori-infected subjects, the incidence of gastric malignancy was similar between those receiving and not receiving eradication therapy (1.4%vs 1.2%). Multivariate analysis showed that intestinal metaplasia was the only independent factor predicting subsequent development of gastric malignancy in H. pylori-infected subjects with an odds ratio of 4.5 (95% CI 1.1-19.1).


CONCLUSIONS
In this prospective cohort study, all gastric malignancies, including adenocarcinoma and lymphoma, developed in H. pylori-infected patients. The finding implies that H. pylori is a necessary cause of most gastric malignancies. Follow-up for H. pylori-infected patients who have intestinal metaplasia is indicated.
Hsu
Ping-I
PI
Division of Gastroenterology and General Medicine, Department of Medicine, Kaohsiung Veterans General Hospital and National Yang-Ming University, Kaohsiung, Taiwan.
Lai
Kwok-Hung
KH
Hsu
Ping-Ning
PN
Lo
Gin-Ho
GH
Yu
Hsien-Chung
HC
Chen
Wen-Chi
WC
Tsay
Feng-Woei
FW
Lin
Hui-Chen
HC
Tseng
Hui-Hwa
HH
Ger
Luo-Ping
LP
Chen
Hui-Chun
HC
D000230:Adenocarcinoma / Q000382:microbiology*; D016009:Chi-Square Distribution; D016099:Endoscopy, Gastrointestinal; D005260:Female; D016481:Helicobacter Infections / Q000150:complications*; D016480:Helicobacter pylori; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000453:epidemiology / Q000382:microbiology*; D013624:Taiwan