NITRITE, N-NITROSO COMPOUNDS, AND OTHER ANALYTES IN PHYSIOLOGICAL FLUIDS IN RELATION TO PRECANCEROUS GASTRIC-LESIONS

Levels of gastric juice nitrite, several urinary N-nitroso compounds, and other analytes were examined among nearly 600 residents in an area of Shandong, China, where precancerous gastric lesions are common and rates of stomach cancer are among the world's highest. Gastric juice nitrite levels were considerably higher among those with gastric juice pH values above 2.4 versus below 2.4. Nitrite was detected more often and at higher levels among persons with later stage gastric lesions, especially when gastric pH was high. Of those with intestinal metaplas ia, 17.5% had detectable levels of gastric nitrite, while this analyte was detected in only 7.2% of those with less advanced lesions. Relati ve to those with undetectable nitrite, the odds of intestinal metaplas ia increased from 1.5 (95% confidence interval = 0.6-4.1) to 4.1 (95% confidence interval = 1.8-9.3) among those with low and high nitrite c oncentrations, respectively. Urinary acetaldehyde and formaldehyde lev els also tended to be higher among those with more advanced pathology, particularly dysplasia. However, urinary excretion levels of total N- nitroso compounds and several nitrosamino acids differed little among those with chronic atrophic gastritis and intestinal metaplasia and dy splasia, consistent with findings from recent studies in the United Ki ngdom, France, and Colombia. The data from this high-risk population s uggest that elevated levels of gastric nitrite, especially in a high p H environment, are associated with advanced precancerous gastric lesio ns, although specific N-nitroso compounds were not implicated.