Chronic atrophic gastritis and risk of N-nitroso compounds carcinogenesis.

Chronic atrophic gastritis is considered a precancerous condition for carcinoma of the stomach. To evaluate the correlation between progressive alterations in the mucosa and gastric juice microenvironmental factors, retained involved on N-nitroso compounds carcinogenesis, detailed analyses of biochemical and microbiological parameters such as pH, total viable counts (TVC), nitrate reductase positive bacterial counts (NRPBC), nitrite (NO2-) and thiocyanate (SNC-) levels, were carried out on 56 fasting gastric juices samples obtained at endoscopy from 28 patients with chronic atrophic gastritis (CAG), 14 with gastric cancers (GC), and 14 normal controls (NC). The mean values of pH, nitrite, TVC, and NRPBC were significantly lower in the juices of NC than in those of CAG and GC patients. Furthermore, the mean levels of the same parameters were higher in GC than in CAG juices. No significant difference was found in the three groups for SCN- level which principally resulted influenced by smoke habit. The 28 patients with CAG were subdivided into two groups (Group A = Diffuse chronic atrophic gastritis--DCAG; Group B = Multifocal chronic atrophic gastritis--MCAG) according to the involvement of gastric corpus and fundus besides antrum by a process of mucosal atrophy. The mean levels of pH, nitrite, TVC, and NRPBC were significantly higher in MCAG than in normal controls but statistically lower in reference to DCAG and cancers. In these two groups no difference was found for the same variables. The percentage of contaminated juices was higher for DCAG and cancers in respect to MCAG but no difference was found between DCAG and neoplastic stomachs. The results of this study suggest that the DCAG could be considered as the chronic atrophic gastritis type more exposed to the risk of N-nitroso compounds carcinogenesis.