| The relationship between Helicobacter pylori and digestive diseases has been paid more and more attention since 1983,the year H.pylori was found by Barry J Mashall and J Robin Warren. In the past two decades, the association of H.pylori and gastric cancers were well established and H.pylori was classified as a group 1 carcinogen in 1994.Linzhou and nearby counties, such as Huixian and Anyang in Henan Province are the high incidence and mortality area for esophageal squamous cell carcinoma (SCC)and gastric cardia adenocarcinoma (GCA).GCA remains the leading cause of cancer related death in these areas with a incidence of 190/100,000. Recent studies by us have indicated that more than 95% GCA originated at the gastric cardia in high incidence area in Henan. In contrast, the true GCA in western countries occupies only about 25% and most of which is low-esophagus adenocarcinoma.Intestinal metaplasia (IM) might be an important manifestation of precancerous lesion of GCA. Our research group demonstrates that, the detection rate of IM in cases with GCA is apparently higher than that in symptom-free subjects. IM occurred more frequently in dysplasia (DYS) than in chronic superficial gastritis (CSG) and chronic atrophy gastritis (CAG). But some studies in western countries showed that IM in gastric cardia had a low-risk for carcinogenesis. These studies indicate that IM and GCA in high incidence area in Henan may have a unique mechanism of carcinogenesis and related biomarkers.The histological feature is similar between cardia and gastric antrum. It is widely accepted that chronic H.pylori infection causes non-cardiac gastric carcinoma, but the effect of H.pylori infection on GCA risk has not yet been determined. Observational studies in Western countries indicated no association or inverse association between H.pylori infection and GCA. On the contrary, most researchers in Asian countries supported at least a trend of positive association between H.pylori infection and GCA.The present study was undertaken to determine the H.pylori infection rates of serum, GCA tissue and IM adjacent to GCA on the same subjects from high incidence area for GCA. We aim to clarify the relationship between H.pylori infection and the risk of GCA, especially IM adjacent to GCA and to determine whether a high-risk group for GCA can be selected by serological prescreening.2.1 Study population109 resected GCA tissues were enrolled from GCA patients in Linzhou Cancer Hospital, Linzhou Central Hospital and Anyang Cancer Hospital in Henan from 2006 to 2009. All subjects provided blood samples. Either chemotherapy or radiotherapy had not been applied to all the patients before surgical operation.105 gastric cardia biopsies were collected from symptom-free subjects at the high-incidence areas for esophageal and gastric cardia cancers in Henan. None of them took medicines. 2.2 MethodsAll the specimens were fixed by 85% alcohol, embedded by paraffin, sliced continuously 5um, HE staining histopathology. Histological analysis (HE method) was applied to determine the detection rate of IM. H.pylori was detected based on modified Giemsa staining. Helicobacter pylori Kit was undertaken to determine the positive rate of Hp in serum.2.3 StatisticsTheχ2 test and Kappa Test were used for the statistical analysis (P<0.05 was considered significant) with software SPSS 17.0.3.1 The H.pylori infection rates of serum, GCA tissues and adjacent tissues to GCA on the same subjectsThe H.pylori infection rates of serum, GCA tissues and adjacent tissues to GCA were 48%,9% and 44%, respectively, there were statistical significance among the detection rates of H. pylori infection (χ2=44.166, P<0.05). There was no statistical significance between the H.pylori infection rates of serum and adjacent tissues to GCA (χ2=0.296, P>0.05).There were statistical significance between the H.pylori infection rates of GCA tissues and serum, adjacent tissues to GCA respectively (χ2=39.759, P<0.05,χ2=33.922,P<0.05).3.2 The H.pylori infection rates of cardia mucosa with cases and healthy controlsH.pylori infection rates for subjects with adjacent tissues to GCA were 44%, compared with 10% for symptom-free control subjects. There was statistical significance between the H.pylori infection rates in symptom-free control subjects and cardia mucosa lesions in different groups (χ2=10.975,P<0.05).3.3 The rate of IM adjacent to GCA in H.pylori positive and negativeThere were 28 samples detected with IM adjacent to GCA (26%,28/109).The rate of IM adjacent to GCA was 38% and 16% in H.pylori positive and H.pylori negative. There was statistical significance in differences in the rate of IM. (χ2=6.269,P<0.05).3.4 The consistency of H.pylori infection in serum and GCA tissuesThere was forward consistency in two methods (P=0.000), but consistency level was not satisfactory.4.1 The H.pylori infection rates in subjects with GCA tissues and adjacent tissues to GCA was higher than that in symptom-free subjects in high incidence area in Henan, which indicates that H.pylori may be a risk factor for GCA.4.2 IM adjacent to GCA occurred frequently in high incidence area in Henan. The rate of IM adjacent to GCA in H.pylori positive group was higher than that in H.pylori negative one, indicating which there was correlation between H.pylori and IM adjacent to GCA.4.3 The positive rate of H.pylori infection in tissue was different from that of serum. Consistency level was not satisfactory, which indicates that serologic test cannot substitute for histopathological examination for H.pylori infection. A high-risk group for GCA cannot be selected by serological prescreening. |
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