title: Effects of Helicobacter pylori infection and smoking on gastric cancer incidence in China: a population-level analysis of trends and projections.
abstract: OBJECTIVE
  Although gastric cancer incidence is declining in China, trends may differ from historical patterns in developed countries. Our aim was to (1) retrospectively estimate the effects of Helicobacter pylori (H. pylori) and smoking on past gastric cancer incidence and (2) project how interventions on these two risk factors can reduce future incidence.
  
  
  METHODS
  We used a population-based model of intestinal-type gastric cancer to estimate gastric cancer incidence between 1985 and 2050. Disease and risk factor data in the model were from community-based epidemiological studies and national prevalence surveys.
  
  
  RESULTS
  Between 1985 and 2005, age-standardized gastric cancer incidence among Chinese men declined from 30.8 to 27.2 per 100,000 (12%); trends in H. pylori and smoking prevalences accounted for >30% of overall decline. If past risk factor trends continue, gastric cancer incidence will decline an additional 30% by 2050. Yet, annual cases will increase from 116,000 to 201,000 due to population growth and aging. Assuming that H. pylori prevention/treatment and tobacco control are implemented in 2010, the decline in gastric cancer incidence is projected to increase to 33% with universal H. pylori treatment for 20-year-olds, 42% for a hypothetical childhood H. pylori vaccine, and 34% for aggressive tobacco control.
  
  
  CONCLUSIONS
  The decline in gastric cancer incidence has been slower than in developed countries and will be offset by population growth and aging. Public health interventions should be implemented to reduce the total number of cases. Electronic supplementary material The online version of this article (doi:10.1007/s10552-009-9397-9) contains supplementary material, which is available to authorized users.
authors.affiliation: Center for Health Decision Science, Harvard School of Public Health, 718 Huntington Avenue, 2nd Floor, Boston, MA 02115, USA. jyeh@hsph.harvard.edu
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Yeh
authors.forename: Sue J
authors.initials: SJ
authors.lastname: Goldie
authors.forename: Karen M
authors.initials: KM
authors.lastname: Kuntz
authors.forename: Majid
authors.initials: M
authors.lastname: Ezzati
mesh_terms: D000328:Adult; D017677:Age Distribution; D002277:Carcinoma / Q000453:epidemiology* / Q000209:etiology; D002681:China / Q000453:epidemiology; D015331:Cohort Studies; D005260:Female; D005544:Forecasting; D016481:Helicobacter Infections / Q000150:complications / Q000453:epidemiology*; D016480:Helicobacter pylori / Q000502:physiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011153:Population; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology*; D013274:Stomach Neoplasms / Q000453:epidemiology* / Q000209:etiology; D055815:Young Adult