| Objective: Incidence of gastric cancer has been declining worldwidely for past several decades. At the same time, the sub-sites of gastric carcinoma changed significantly. The incidence of distal gastric carcinoma has been decreased, whlie that of proximal gastric carcinoma has been increased. Studies in our country showed that the incidence of cardiac carcinomas significantly increased and accounted for two thirds of all gastric carcinomas of the residents in Cixian County where is a high-risk area of esophageal carcinoma in Hebei province, China.The changing trends in the sub-site of gastric carcinoma caused the intensive concerns of oncologists. The exact mechanism for the changing trend in the sub-site of gastric carcinoma is still not clear. Studies showed that there were some differences in the etiology and carcinogenesis of cardiac carcinoma and distal gastric carcinoma. Cardiac carcinoma is considered an unique entity of gastric cancer.Recent studies showed that biological factors played important roles in the development and progression of some carcinomas. Helicobacter pylori (H. pylori) is a spiral gram-negative bacterium that colonises the stomach. It is one of the most common infections in humans with an estimated prevalence of 50% worldwide and 90% in developing countries. In 1994, H.pylori was classified as a group 1 carcinogen by the International Agency for Research on Cancer. The putative role of H.pylori in the gastric carcinogenesis has been widely studied. Epidemiological studies have clearly shown that H. pylori infection is associated with gastric carcinoma, but the relationship between H.pylor infection and cardiac carcinoma is still controversial. Meta-analysis demonstrated a weak association between H. pylori infection and cardiac carcinoma. Recently, a Japanese reported an opposite conclusion which suggestted that H.pylor infection be closely associated with cardiac carcinoma. The relationship between H. pylori infection and cardiac carcinoma requires in-deep assessment.Epstein-Barr virus (EBV) oncoprotein Latent Membrane Protein 1 (LMP1) is an aggregated membrane protein responsible for most of the carcinogenic properties of EBV. LMP1 is expressed in all the EBV-associated malignancies and transform cell in vitro, by altering the control of cell cycle and apoptosis. In 1990, Burke first reported a case of EBV positive gastric carcinoma.Studies show that EBV-associated gastric carcinoma predominately located on proximal stomach and gastric body in general.Up to now, studies on relationship between biological factors and gastric carcinoma were mainly focused on distal gastric carcinoma, few study involved in the sub-site of gastric carcinomas.The aim of this stuy is to explore the putative relationship between H. pylori and EBV infection and cardiac and distal gastric carcinoma and to elucidate the carcinogenesis of cardiac carcinoma. H. pylori and EBV were comparatively detected in cardiac carcinoma and distal gastric carcinoma from local residents of high risk area of esophageal carcinoma in Cixian county, Hebei province in China with immunohistochemical method.Method:1 Formalin fixed, paraffin embedded tissue blocks of 190 cases of cadiac carcinoma(CC) and distal gastric carcinoma (DGC), archived from 2005 to 2008 in Department of Pathology, Cixian Hospital were included in this study. All the slides of the cases included in this study were reviewed by two experienced pathologists according to 2000 WHO criterion and the diagnosis confirmed. The detection of H.pylori and EBV LMP1 were immunohistochemically studied in 144 cases of CC and 46 cases of DGC with ElivisionTM plus two-step method.2 The experimental data were statistically analyzed with Chi-square test and Fisher's exact test with statistics software of SPSS13.0 edition.Results:1 The results of immunohistochemical staining1.1 Results of H. pylori staining in gastric carcinomaThe immunoreaction of H. pylori was seen in the mucous layer on the mucosa surface, in gland lumen, surface epithelium of mucosa as well as cytoplasm of cardiac and distal gastric carcinoma cells.Of all the 190 cases of gastric carcinoma including cardiac and distal gastric carcinoma, the detection rate of H. pylori infection was 58.95% (112/190).The detection rate of H.pylori was related to Laurén type. The detection rate of H.pylori in intestinal type was 62.96%, which was significantly higher than that in diffuse type (35.71%, P<0.05). No association was found between H. pylori infection and clinical pathologic features of gastric carcinoma, such as gender and age of the patients and differentiation of tumor. There is no significant change in detection rate of H. pylori in recent four years.1.2 H. pylori detection and clinical pathological signi- ficance in CC and DGCThe detection rate of H. pylori P in 144 cases of cardiac carcinoma was 56.94%, while that in distal gastric carcinoma was 65.22%. No significant statistical difference was found between the two groups(χ2= 0.986,P>0.05).There were no significant relationship between H.pylori detection and gender and age of the patient, differentiation and histological types of tumor in cardiac carcinoma.Among the distal gastric carcinoma cases, the detection of H.pylori was closely related with Laurén's type, the detection rate in intestinal types was significantly high than that in diffuse types (71.79% vs 28.57%,P<0.05). No relationship between H.pylori detection and gender and age of the patient, differentiation was found in the cases.2 Detection of EBV LMP1 in CC and DGCImmunohistochemical staining results showed that strong positive staining was resulted in positive control slides, while no positive expression of EBV LMP1 was found in the 190 cases.Conclusion:1 There is no significant difference in the H.pylori detection rate between CC and DGC in the residents in high-risk area of esophageal tumor in Cixian County.2 H. pylori infection was related with Laurén's type in distal gastric carcinoma.3 No positive expression of EBV LMP1 was found in CC and DGC,suggestting that EBV be not associated with the trends and changes in the sub-site of gastric carcinoma in the high-risk area of esophageal carcinoma in Cixian County. |
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