Preventing stomach cancer in East Asia: Developing markers to identify individuals at highest risk for targeted Helicobacter pylori eradication
Date: 09/21/2017 (Thu)
Time: 3:30pm- 5:00pm
Location: Gross Hall 270
Organizer: Giovanna Merli
Meeting Schedule: (Not currently open for scheduling. Please contact the seminar organizer listed above.)
3:30pm - Seminar Presentation (3:30pm to 5:00pm)
Additional Comments: Abstract: Gastric cancer is the second most deadly cancer in the world, and incidence and mortality rates are highest in East Asia. Infection with Helicobacter pylori, the strongest known risk factor for gastric cancer, is also endemic throughout East Asia, but only a small percentage of infected individuals ever develop gastric cancer. Due to the high level of genetic variation among H. pylori isolates, it may be possible to identify risk markers that could classify H. pylori-infected individuals into high- and low-risk groups, presenting a unique opportunity for cost-effective disease prevention. This is especially significant because H. pylori eradication has been found to effectively reduce gastric cancer incidence. Currently, however, there is no known biomarker that is feasibly assessed that can estimate a substantially significant increase in risk for gastric cancer. Utilizing novel H. pylori multiplex serology, we found that increasing number of sero-positive results to six H. pylori proteins (Omp, HP0305, HyuA, HpaA, CagA, and VacA) may be a novel biomarker panel for gastric cancer risk in among urban men living in Shanghai, China. We have found that this biomarker panel is significantly stronger at discriminating risk than evidence of the CagA protein alone, resulting in those individuals with antibodies to all six indicated H. pylori proteins having a three- to five-fold increase in risk of distal gastric cancer. We then replicated these results in a consortium of eight prospective cohort studies in the high gastric cancer-incidence populations of China, Japan, and Korea; and finally validated our novel H. pylori protein-specific biomarkers of gastric cancer risk in a cross-sectional study involving baseline endoscopy in Linqu County, an area of China with particularly high gastric cancer rates. We then built a predictive model for gastric cancer risk in East Asia that includes H. pylori blood biomarkers that enables us to categorize individuals into high and low-risk groups for prevalent precancerous lesions. Finally, we have explored the interaction of infection with a high-risk subtype of H. pylori with the established gastric cancer risk factors of diet and smoking. By ascertaining and validating a risk prediction model that predicts increased risk in high-incidence populations, we have sought to create the opportunity to substantially increase prevention of this deadly cancer through targeted prevention strategies among H. pylori-infected individuals at highest risk, while also reducing unnecessary antibiotic use among those at low risk.