title: Frequent loss of heterozygosity but rare microsatellite instability in oesophageal cancer in Japanese and Chinese patients.
abstract: Reported frequencies for microsatellite instability (MSI) in oesophageal cancer differ widely in the literature, perhaps due to the high incidence of loss of heterozygosity (LOH) in this cancer. Using high-resolution fluorescent microsatellite analysis (HRFMA), we analysed microsatellite alterations in detail in 50 Japanese and 50 Chinese patients with squamous cell carcinoma in the oesophagus. In HRFMA, several devices have been developed to improve the detection characteristics, reproducibility of polymerase chain reaction and the migration accuracy of electrophoresis. All the alterations observed were separable into MSI, LOH and alterations ambiguous for both. MSI was rare in these panels of oesophageal carcinomas. The frequencies of MSI in the Japanese and Chinese subjects were 8 and 4%, respectively. All the alterations were mild (within 2 base pairs) and were observed in a limited number of markers. More drastic types of MSI, such as those typical in colorectal cancer, were not observed. On the other hand, the incidence of LOH was high, reaching 50% for the Japanese and 70% for the Chinese subjects. In many of these cases, LOH was observed in multiple microsatellite markers. The frequency of LOH in each marker was not apparently biased. Although in many cases MSI and LOH were clearly distinguished with use of the sensitive and quantitative fluorescent assay, theoretically indistinguishable patterns were noted in some cases. In conclusion, MSI is rare and LOH predominates in squamous cell carcinoma in the oesophagus.
authors.affiliation: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Koshi
authors.initials: K
authors.lastname: Araki
authors.forename: Bing
authors.initials: B
authors.lastname: Wang
authors.forename: Kaname
authors.initials: K
authors.lastname: Miyashita
authors.forename: Qingping
authors.initials: Q
authors.lastname: Cui
authors.forename: Shinji
authors.initials: S
authors.lastname: Ohno
authors.forename: Hideo
authors.initials: H
authors.lastname: Baba
authors.forename: Ru Gang
authors.initials: RG
authors.lastname: Zhang
authors.forename: Keizo
authors.initials: K
authors.lastname: Sugimachi
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Maehara
authors.forename: Shinya
authors.initials: S
authors.lastname: Oda
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People / Q000235:genetics*; D002294:Carcinoma, Squamous Cell / Q000235:genetics*; D002681:China; D004273:DNA, Neoplasm / Q000032:analysis*; D004938:Esophageal Neoplasms / Q000235:genetics*; D005260:Female; D005453:Fluorescence; D005787:Gene Frequency; D006801:Humans; D007564:Japan; D019656:Loss of Heterozygosity; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged
chemical_list: D004273:DNA, Neoplasm