RESUMO
BACKGROUND: Although there have been some reports on microsatellite alterations in gastric cancer, findings are inconsistent regarding the associations between histological classification and microsatellite instability (MSI). In the present study, we attempted to determine whether Lauren's histological subtypes are related with MSI status. METHODS: Paraffin-embedded tissue samples from 14 diffuse-type and 14 intestinal-type gastric adenocarcinomas were matched up according to patient gender and age. Mononucleotide markers (BAT25 and BAT26) and dinucleotide markers (D2S123, D5S346, and D17S250) were used for MSI analyses. Microsatellite genotypes were categorized in terms of high MSI incidence (MSI-H, > 30% positive marker) or low MSI incidence (MSI-L, < 30% positive marker). Losses of hMLH1 and hMSH2 protein expression were immunohistochemically studied. RESULTS: MSI-H was observed in 11 cases (78%) of the 14 intestinal-type cases as compared to 3 (21%) of the 14 diffuse-type cases (p=0.007). In MSI-H tumors, 10 cases (71%) showed losses of hMLH1 protein expression, while 2 cases (14%) in MSI-L tumors showed losses of hMLH1 protein expression (p=0.006). CONCLUSION: MSI-H tumors are more frequently found in intestinal-type gastric cancer, which suggests the possibility that there are different pathogenic pathways in gastric carcinogenesis according to histologic type.
Assuntos
Idoso , Feminino , Humanos , Masculino , Adenocarcinoma/epidemiologia , Pareamento Incorreto de Bases/genética , Estudo Comparativo , Regulação Neoplásica da Expressão Gênica , Genótipo , Incidência , Coreia (Geográfico)/epidemiologia , Repetições de Microssatélites/genética , Proteínas de Neoplasias/genética , Proteínas Nucleares/genética , Reação em Cadeia da Polimerase , RNA Mensageiro/genética , Estudos Retrospectivos , Neoplasias Gástricas/epidemiologiaRESUMO
BACKGROUND/AIMS: In western countries, symptomatic diverticulitis develops in about 20% of the population with colonic diverticula, and it is mainly located at the left-sided colon. The clinical characteristics of diverticulitis have rarely been investigated although its incidence is increasing in Asia including Korea. The aim of this study was to compare diverticulitis with asymptomatic diverticulosis and to compare the clinical characteristics of right-sided diverticulitis with those of left-sided diverticulitis. METHODS: We retrospectively investigated the medical records of the patients who had symptoms and signs of diverticulitis. Their diagnosis was confirmed with computed tomography, barium study, colonoscopy and/or operations at Samsung Medical Center from September 1998 to February 2002. The control cases of asymptomatic and incidental diverticulosis were randomly selected during routine health check-up after matching age and sex. RESULTS: Twenty-seven patients with diverticulitis (male : female=14 : 13) were included. The mean age was 53 (27~86). The ratio of right and left diverticulitis was 20:7, which was similar to the ratio of diverticulosis. The complications, especially perforation, were more frequent in the patients with left-sided diverticulitis (p<0.05). CONCLUSIONS: Colonic diverticulitis is more prevalent at the right colon and left colonic diverticulitis has more complications than right colonic diverticulitis in Korea.