Gastric juice nitrite and vitamin C in patients with gastric cancer and atrophic gastritis: is low acidity solely responsible for cancer risk?
BACKGROUND
N-nitroso compounds are carcinogens formed from nitrite, a process that is inhibited by vitamin C in gastric juice. Helicobacter pylori infection has been reported to increase nitrite and decrease vitamin C in gastric juice. Therefore, susceptibility to gastric cancer in H. pylori-infected patients may be derived from increased N-nitroso compounds in gastric juice. However, most H. pylori-infected patients do not develop gastric cancer.


OBJECTIVE
To investigate additional factors that may affect susceptibility to gastric cancer, we compared nitrite and vitamin C levels in gastric juice from H. pylori-infected patients with and without gastric cancer.


METHODS
Serum and gastric juice were obtained from 95 patients undergoing diagnostic endoscopy, including those with normal findings, duodenal ulcer, gastric ulcer, atrophic gastritis and gastric cancer. Serum was analysed for H. pylori antibody, nitrate and nitrite, gastrin and pepsinogens; gastric juice was analysed for pH, nitrite and vitamin C.


RESULTS
pH and nitrite levels were increased and vitamin C levels decreased in the gastric juice of patients with atrophic gastritis and gastric cancer compared with other patients. However, in patients with a similar gastric acidity (pH 5-8), nitrite concentrations in the gastric juice were significantly higher and vitamin C levels significantly lower in patients with gastric cancer than in those with atrophic gastritis.


CONCLUSIONS
Although hypochlorhydria increases intraluminal nitrite and decreases intraluminal vitamin C, which increases the intraluminal formation of N-nitroso compounds, our results indicate that patients with gastric cancer may have additional factors that emphasize these changes.
Kodama
Kanji
K
Department of Medicine and Molecular Science, Graduate School of Biomedical Science, Hiroshima University, Japan.
Sumii
Koji
K
Kawano
Masanori
M
Kido
Tamako
T
Nojima
Keiko
K
Sumii
Masaharu
M
Haruma
Ken
K
Yoshihara
Masaharu
M
Chayama
Kazuaki
K
D000368:Aged; D001205:Ascorbic Acid / Q000032:analysis*; D005260:Female; D005750:Gastric Juice / Q000737:chemistry*; D005757:Gastritis, Atrophic / Q000378:metabolism*; D016481:Helicobacter Infections / Q000150:complications / Q000378:metabolism; D016480:Helicobacter pylori; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D009573:Nitrites / Q000032:analysis*; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000737:chemistry* / Q000382:microbiology
D009573:Nitrites; D001205:Ascorbic Acid