Correlation Of Hp Infection In Gastric Cardia, Antrum And Esophageal Epithelia: Comparative Study On The Subjects From High-and Low-incidence Areas For Esophageal Cancer

1 BACKGROUND AND OBJECTThe relationship between Helicobacter pylori (Hp) and gastric cancer has been paid more and more attention since 1983, the year Hp was found by Barry J Mashall and J Robin Warren. Recent studies have demonstrated that a high Hp infection ratio in general people, especially in developing countries. Hp infection is closely related to not only the digestive diseases but also the blood system diseases, coronary heart disease and ischemic cerebrovascular disease. Esophageal cancer and gastric cancer have a high incidence in northern China, especially in Linzhou, Huixian, Anyang and nearby counties in Henan province. It is unclear whether Hp infection was related to esophageal cancer and cardia cancer. Studies from our laboratory and other scholars have showed that Hp infection rate is different in cardia and antrum at high-incidence areas for esophageal and cardia cancers, lower in cardia than in antrum. Preliminary research results suggest that esophageal basic cell hyperplasia lesions are lighter in patients with Hp infection positive in cardia, however, the effect of Hp infection in cardia and gastric antrum to esophageal epithelial cell proliferation in the same individual is not clear. The present study was thus designed to further characterize the Hp infection in different parts of the stomach and the relationship between the infection area and lesions in esophagus, gastric cardia and antrum both in high- and low-incidence areas for esophageal cancer in order to facilitate the understanding of the pattern of Hp infection in cardia and stomach antrum and its infect on the lesions of esophagus, gastric cardia and antrum epithelia.2 MATERIALS AND METHODS2.1 MaterialsBiopsies at esophagus, gastric cardia and antrum were collected from 152 symptom-free subjects at the high-incidence areas for esophageal and gastric cardia cancers in Henan. None of them takes medicines, including 117 gastric antrum biopsies, 105 gastric cardia biopsies, and 152 esophageal biopsies. Seventy-nine gastric cardia and antrum biopsies were collected from Puyang, the low-incidence areas for esophageal cancer, including 39 gastric antrum biopsies and 40 gastric cardia biopsies.2.2 MethodsAll the specimens were fixed by 85% alcohol, embedded by paraffin, sliced continuously 5um, HE staining histopathology. According to the cell morphological changes and tissue architecture, the esophageal epithelia was classified into normal (Nor), basic cell hyperplasia (BCH), dysplasia (Dys), and gastric antrum and cardia epithelia were classified into Nor, chronic superficial gastritis (CSG), chronic atrophy gastritis (CAG), and dysplasia (Dys). Hp was detected based on modified Giemsa. Every slide was randomly observed ten high power fields, to record Hp infection. Hp positive was classified into three degrees. The data were analyzed by SPSS10.0 statistical software using Fisher s exact test of probabilities. The test used for the statistics (P<0.05) was considered significant.3 RESULTS3.1 The relationship between Hp infection in cardia and antrum and the lesions in esophagus, cardia and antrumHp infection rate in cardia was obviously lower (10%) than in antrum (59%) (p<0.05). The detection of lesions at antrum epithelia increased as higher with the infection degree of Hp rate. No difference was observed between Hp infection in cardia and antrum and different age and sex.It was note worthy that the detection of BCH and Dys in esophageal epithelia was obviously higher in Hp negative in cardia than in positive, while there was no such results observed in Hp infection in antrum, which indicated that Hp infection in cardia might be a protection for esophageal epithelia.3.2 Comparison of Hp infection in cardia and antrum in high- and low-incidence areas for esophageal cancerPositive rate of Hp infection in cardia was much higher in low-incidence areas for esophageal cancers than in high-incidence areas for esophageal cancer (30% vs 10%) (p<0.05). However, positive rate of Hp infection in antrum between the high-and low-incidence areas for esophageal cancer was no significant difference (p>0.05), which further suggested that there might be a negative correlation between Hp infection in cardia and esophageal carcinogens.3.3 Relationship between Hp infection and gender and age at high- and low-incidence areasThere was no significant difference in Hp infection rate in gender at high- and low-incidence areas for esophageal cancer (p>0.05), however, as the age increased the Hp infection rate had an increasing trend (p<0.05).4 CONCLUSIONS4.1 Hp infection rate in cardia is obviously higher in low-incidence areas for esophageal cancer than in high-incidence areas. There is a low lesion detection rate in esophageal epithelium as Hp infection in cardia was positive, which indicate that Hp infection in cardia might be a protection for esophageal epithelium.4.2 Hp infection rate in antrum was obviously lower in low-incidence areas for esophageal cancer than in the high-incidence areas. There was no difference between Hp infection in antrum and lesions in esophageal epithelium.4.3 The positive rate of Hp infection in residents from low-incidence areas for esophageal cancer has showed an increasing tendency with age, which is different with the subjects from the high-incidence areas for esophageal cancer.