The non-invasive diagnosis of precancerous changes of stomach mucosa
Pasechnikov VD, Chukov SZ, Kotelevets SM, Mostovov AN, Polyakova MB, Mernova VP

Purpose: To detect the Helicobacter pylori (H.pylori)-induced gastric precancerous lesions leading to cancer formation, and to evaluate the possibility of non-invasive screening of dyspeptic patients to identify those having high risk of gastric cancer.
Material and methods: 178 consecutive H.pylori-positive dyspeptic patients after assessment of serum pepsinogen-1 (PG-1) and gastrin-17 (G-17) levels by enzyme immunoassay were examined with endoscopy and histology. The serologic and morphologic results were compared with estimating the sensitivity, specificity and prognostic values of the tests.
Results: There was statistically significant reverse dependence between the presence and severity of stomach mucosal atrophy (in antrum or corpus) and the proper serologic markers of stomach functional activity (G-17 or PG-1). On the other hand, the presence and the degree of intestinal metaplasia, dysplasia and gastric cancer did not correspond to the serum levels of G-17 or PG-1. The serologic method was quite sensitive in the diagnosis of non-atrophic and severe antral and corpus gastritis. Also, it was characterized by the high positive and negative prognostic values. Additionally, we have established the obvious advantage of the chromoendoscopy method in the diagnosis of intestinal metaplasia in the stomach epithelium.
Conclusions: The assays of serum G-17 and PG-1 levels can be offered as the screening tool for atrophic gastritis. The positive serologic results require further chromoendoscopic examination with mucosal biopsy to disclose the probable progression of atrophic process with development of intestinal metaplasia, dysplasia or gastric cancer. 

Key words:   gastric cancer, pepsinogen, gastrin, non-invasive screening, chromoendoscopy.