title: The relative frequency of the Helicobacter pylori infection in proximal gastric cancers.
abstract: Gastric cancer with the annual mortality of 700 000 is the second cause of death in the world. Iran with the annual incidence of 37 in 100 000 is among areas with high risk of gastric cancer. In Iran, Khuzestan Province with the annual incidence of 10 -15 in 100 000 is among areas with moderate risk. The role of Helicobacter pylori infection in distal gastric cancer as one of the most important risk factors of gastric ulcer has been proved but its role in proximal gastric cancer is controversial. In recent decades, the incidence of proximal cancers has increased. The aim of the study was to survey the relative frequency of Helicobacter pylori infection in the people with proximal cancer and to compare it with this infection frequency in the distal cancer.
  
  
  METHODS
  Relative frequency of Helicobacter pylori infection was surveyed by pathology tests and biopsy gastric mucosa sample staining with H&E in the patients with proximal and distal gastric ulcer whose cancers were proved by pathology method and also in the people who were healthy in terms of a gastric cancer. Data were statistically analyzed by frequency tables and chi square test.
  
  
  RESULTS
  One hundred and seventeen people entered the study. Among 32 patients with the proximal cancer, 21 people were with the positive Helicobacter pylori (65.6%) and 11 people (34.4%) were with the negative Helicobacter pylori (p<0.01). Among 30 patients with the distal cancer, 26 people were with positive Helicobacter pylori (86.7%) and four people were with negative Helicobacter pylori (13.3%) (p<0.01); 55 people were without the cancer, which among them, 40 people were with the positive Helicobacter pylori (72.7%); and 15 people were with the negative Helicobacter pylori (37.7%) (p<0.01). In comparison of the frequency of Helicobacter pylori infection in the patients with the proximal cancer, a weak significant difference exists (p = 0.053). Comparing the frequency of Helicobacter pylori infection in the patients with the gastric cancer and people without the cancer, no significant difference existed (p = 0.703).
  
  
  CONCLUSIONS
  A weak significant difference existed between the frequency of Helicobacter pylori infection in patients with the proximal gastric cancer and the frequency of these infections in the patients with the distal cancer. So, eradicating Helicobacter pylori infection can be effective in preventing the distal gastric cancers in addition to preventing the proximal gastric cancers.
authors.forename: Abdolhassan
authors.initials: A
authors.lastname: Talaiezadeh
authors.forename: Eskandar
authors.initials: E
authors.lastname: Hajiani
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Tarshizi
mesh_terms: D000328:Adult; D000368:Aged; D015897:Comorbidity; D005260:Female; D005753:Gastric Mucosa / Q000382:microbiology*; D016481:Helicobacter Infections / Q000453:epidemiology*; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D015994:Incidence; D007492:Iran / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000453:epidemiology* / Q000382:microbiology*