Helicobacter pylori infection in 1st degree relatives of Chinese gastric cancer patients.
OBJECTIVE
Familial aggregation of gastric cancer has been linked to familial clustering of Helicobacter pylori infection. Patterns and risk factors associated with H. pylori infection were investigated in 1st degree relatives of Chinese gastric cancer patients.


METHODS
Gastric cancer relatives were invited for screening endoscopy. H. pylori infection was diagnosed by endoscopic and serological methods.


RESULTS
Among the 270 cancer relatives examined, 161 (59.6%) were found to be infected with H. pylori. The prevalence of infection in cancer relatives was significantly higher than age- and gender-matched dyspeptic control (45.5%, p=0.0006). The mean age of H. pylori-infected relatives was significantly older than that of non-infected relatives (43.9 versus 38.3 years; p<0.001). The prevalence of H. pylori infection was higher in those with more siblings (p=0.013, chi(2) test for trend). Moreover, individuals whose siblings had stomach cancer were more likely to have H. pylori infection than those with a parental history of cancer (68.2% versus 51.8%, p=0.007). In contrast, the youngest sibling had a significantly lower H. pylori infection rate than other siblings (39.2% versus 64.2%, p=0.001). Using multiple logistic regression, it was found that age >45 years (OR=1.8; 95% CI, 1.02-3.3) and a history of gastric cancer in siblings (OR=1.9; 95% CI, 1.06-3.3) were independent risk factors for H. pylori infection, and that the youngest sibling in the family had a reduced risk (OR=0.45; 95% CI, 0.24-0.84).


CONCLUSIONS
This study identifies the patterns and risk factors for H. pylori in gastric cancer relatives, which may shed light on the evolving epidemiology of H. pylori infection in Chinese patients.
Institute of Digestive Diseases, Shatin, Hong Kong. wkleung@cuhk.edu.hk
Wai K
WK
Leung
Enders K W
EK
Ng
Candice C H
CC
Lam
Kui-Fat
KF
Chan
Wing Y
WY
Chan
Alex C M
AC
Auyeung
Justin C Y
JC
Wu
Jessica Y L
JY
Ching
James Y W
JY
Lau
Joseph J Y
JJ
Sung
D000293:Adolescent; D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000032:analysis; D001706:Biopsy; D002681:China / Q000453:epidemiology; D016099:Endoscopy, Gastrointestinal; D005260:Female; D016481:Helicobacter Infections / Q000150:complications / Q000453:epidemiology* / Q000635:transmission; D016480:Helicobacter pylori / Q000276:immunology / Q000302:isolation & purification*; D006801:Humans; D018445:Infectious Disease Transmission, Vertical; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D015995:Prevalence; D011379:Prognosis; D013274:Stomach Neoplasms / Q000150:complications* / Q000235:genetics / Q000473:pathology
D000907:Antibodies, Bacterial