Validation of a blood biomarker for identification of individuals at high risk for gastric cancer.

BACKGROUND: Helicobacter pylori is the leading cause of gastric cancer, yet the majority of infected individuals will not develop neoplasia. Previously we developed and replicated serologic H. pylori biomarkers for gastric cancer risk among prospective cohorts in East Asia, and now seek to validate the performance of these biomarkers in identifying individuals with premalignant lesions.

METHODS: This cross-sectional study included 1,402 individuals from Linqu County screened by upper endoscopy. H. pylori protein-specific antibody levels were assessed using multiplex serology. Multivariable-adjusted logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for prevalent intestinal metaplasia, indefinite dysplasia, or dysplasia, compared to superficial or mild atrophic gastritis.

RESULTS: Compared to individuals sero-negative to Omp and HP0305, individuals sero-positive to both were seven times more likely to have precancerous lesions (OR, 7.43; 95% CI, 5.59-9.88). A classification model for precancerous lesions that includes age, smoking, and sero-positivity to H. pylori, Omp, and HP0305 resulted in an area under the curve (AUC) of 0.751 (95% CI, 0.725-0.777), which is significantly better than the same model including the established gastric cancer risk factor CagA (AUC, 0.718; 95% CI, 0.691 -0.746, pdifference=0.0002).

CONCLUSIONS: The present study of prevalent precancerous gastric lesions provides support for two new serum biomarkers of gastric cancer risk, Omp and HP 0305.

IMPACT: Our results support further research into the serological biomarkers Omp and HP0305 as possible improvements over the established virulence marker CagA for identifying individuals with precancerous lesions in East Asia.