| Epstein-Barr virus (EBV) is an ubiquitous herpes virus which is the causative agent of infectious mononucleosis, almost the entire population more than 25 years old test positive for anti-EBV antibodies, and it may also be found in a wide variety of benign and malignant lesions including oral hairy leukoplakia, inflammatory pseudotumor, Hodgkin's disease, non-Hodgkin's lymphoma, nasopharyngeal carcinoma, gastric carcinoma and some carcinomas of other organs with similar lymphoepithelioma-like features. Most EBV-associated tumours are rare or occur at higher incidence only in certain geographical regions, though the relationship between EBV and gastric carcinoma had been reported frequently, there are some regional differences in the incidence of EBV positive gastric carcinoma as a proportion of all cases of gastric carcinoma, with the highest (16-18%) in the USA and Germany, and the lowest (1.6-10.3%) in China, as reports in this regard are not entirely consistent and the methods employed are of different sensitivity and specificity. There are few papers about the associations of EBV with esophageal carcinoma and colorectal carcinoma, and this associations have not yet been clarified.Molecular testing is increasingly important in the diagnosis and monitoring of patients affected by these diseases. In biopsy tissues, molecular detection of EBV-encoded RNA transcripts by in situ hybridization remains the gold standard for proving that a histopathological lesion is EBV-related. EBV LMP1 immunostains and PCR are used routinely to detect latent EBV in tissues. So, we used ISH tests combined with PCR and histochemical assays to elucidate the relationship between EBV and gastrointestinal tract tumors in this study.We collected 257 paraffin embeded blocks of gastrointestinal tracttumors in Cantonese patients, which included 75 gastric adenocarcinomas and 40 nomal gastric mucosa adjacent to tumors, 52 esophageal carcinomas and 28 nomal esophageal mucosa adjacent to tumors, 130 colorectal tumors and 30 normal colorectal mucosa, all cases were tested with immunohistochemistry(IHC), polymerase chain reaction (PCR) and in situ hybridization (ISH), respectively. Then difference in proportions among the groups were calculated using the SPSS 10.0 statistical software program.This study found 7 gastric carcinoma showed EBER-1 positive, account for 9.3%, in addition, 11 cases(14.7%) were positive in PCR test and 4 cases(5.3%) showed LMP1 signals; 3 cases of normal mucosa were positive in PCR, account for 7.5%, EBER1 or LMP1 was negative in normal mucosa. There was significant differences between the results of ISH, PCR or IHC(p<0.05)3 cases(5.8%) of esophageal carcinomas showed positive lanes by PCR, and 2 cases(7.l%) of normal mucosa adjacent to tumors were PCR positive; no case esophageal carcinomas showed EBER signals, but 2 cases(3.8%) with lymphoid stromal showed EBER positive, 1 cases(1.9%) showed the expression of LMP1, no EBER or LMP1 signals was showed in normal mucosa tissues. There was no significant differences between the results of ISH, PCR or IHC .130 colorectal tumors were used in this study, including 26 adenomas, 22 adenomas with dysplasia, 22 adenomas with cancinomatous change, 36 colon carcinoma and 23 HNPCC, EBER1 detected by ISH were positive in 6 cases(4.6%), including 1 adenoma with dysplasia, 2 adenomas with cancinomatous change and 3 colorectal carcinomas, EBER1 signals were not detected in normal mucosa tissues. IHC detection showed the expression of LMP1 in 7 cases(5.4%), including 1 adenoma,! adenoma with dysplasia,! HNPCC, 2 adenoma with carcinomatous change and 2 colorectal carcinomas. In addition, EBV DNA was tested by PCR in 26 cases(20%), including 5 adenomas, 5 adenomas with dysplasia, 6 adenomas with carcinomatouschange, 6 colorectal carcinomas, 4 HNPCC ; 4 normal mucosa tissues(13.3%) were positive by PCR test. There was no significant differences of the results of ISH, PCR or IHC among the six groups.Our results indicate that EBV is not generally related to the c... |
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