BACKGROUND - Helicobacter pylori is the leading risk factor for gastric cancer, yet only a fraction of infected individuals ever develop neoplasia.
METHODS - To identify potential predictive biomarkers, we assessed the association of 15 antibodies to H. pylori proteins and gastric cancer in a nested case-control study. Blood levels of antibodies were assessed using multiplex serology for 226 incident cases and 451 matched controls from the Shanghai Men's Health Study. ORs and 95% confidence intervals (CI) were calculated using conditional logistic regression.
RESULTS - Seropositivity to four (Omp, HP0305, HyuA, and HpaA) proteins was associated with a 1.5- to 3-fold increased risk for gastric cancer. When excluding cases diagnosed within 2 years of study enrollment, seropositivity to two additional proteins (CagA and VacA) showed significant associations with risk. Compared with individuals with three or fewer seropositive results to the six virulent proteins identified in this population, individuals with four to five seropositive results were at a 2-fold increased risk (OR, 2.08; 95% CI, 1.31-3.30) and individuals seropositive to all six proteins had a 3.5-fold increase in risk (OR, 3.49; 95% CI, 2.00-6.11) for gastric cancer. Among individuals diagnosed at least 2 years after study enrollment, these associations were even stronger (ORs, 2.79 and 4.16, respectively).
CONCLUSIONS - Increasing number of seropositives to six H. pylori proteins may be a risk marker for distal gastric cancer in China.
IMPACT - In a population with a 90% prevalence of CagA-positive H. pylori infection, assessment of additional virulent H. pylori proteins might better identify individuals at high risk for gastric cancer.