title: Six-fold difference in the stomach cancer mortality rate between northern and southern Iran.
abstract: BACKGROUND
  Stomach cancer is the most common cancer in Iran. A multi-ethnic population and wide variation in the environmental risk factors may lead to variations in cancer risk within this country. We have designed an ecological study and evaluated geographical variation regarding mortality from stomach cancer and its established risk factors in Iran.
  
  
  METHODS
  We used the Iranian National Causes of Death Registry and estimated the age-standardized mortality rates (ASMR) of stomach cancer in 29 Iranian provinces, stratified by sex and area of residence (rural/urban).
  
  
  RESULTS
  The average ASMR of stomach cancer among Iranian males was 15 per 100,000 and for females it was 8.1 per 100,000. The highest and lowest mortality rates were observed in Kurdistan with an ASMR of 29.1 per 100,000 in northwestern Iran and Hormozgan that had an ASMR of 5.0 per 100,000 in southern Iran. Males had approximately a two-fold higher ASMR compared to females, as did rural residents when compared with urban residents. The prevalence of H. pylori infection was about 90% in the province of Ardabil (a high-risk area) and 27% in the province of Sistan-Baluchistan (a low-risk area).
  
  
  CONCLUSIONS
  The wide geographical variation and high mortality rate of stomach cancer in Iran is likely due to differences in the exposure to the environmental risk factors among people living in the high- and low-risk areas, particularly H. pylori infection, a well-established risk factor of stomach cancer.
authors.affiliation: Cancer Research Center, Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran. kzendeh@tums.ac.ir
authors.forename: Kazem
authors.initials: K
authors.lastname: Zendehdel
authors.forename: Maryam
authors.initials: M
authors.lastname: Marzban
authors.forename: Azin
authors.initials: A
authors.lastname: Nahvijou
authors.forename: Nahid
authors.initials: N
authors.lastname: Jafari
mesh_terms: D005260:Female; D016481:Helicobacter Infections / Q000150:complications / Q000453:epidemiology; D016480:Helicobacter pylori; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D015995:Prevalence; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D013274:Stomach Neoplasms / Q000209:etiology / Q000401:mortality*