2000 Volume 8 Issue 1-2 Pages 112-124
Micro-satellite instability (MSI) may underlie one of the etiologies in multistep gastric carcinogenesis, which is strongly related with the alteration of DNA mismatch repair genes. There are many reports for this abnormality in sporadic or familial gastric cancer, but only a few in multiple gastric cancer. In order to elucidate the difference between these two groups, we performed the assessment of MSI by 10 micro-satellite markers in 4 multiple and 25 single gastric cancers using fluorescent DNA auto-sequencer. We detected replication errors (RER) in one (25%) of 4 cases of multiple gastric cancer and 2 (8%) of 25 cases of single gastric cancer, which showed no statistical significance between these two groups. Both cases of single cancer were advanced cancers, of which histological types were poorly differentiated adenocarcinoma, and they showed less than 2 positive markers. On the other hand, in the RER positive case of multiple gastric cancer, histological types were well-differentiated adenocarcinoma and early cancers, in which of one lesion indicated that 7 micro-satellite markers were positive. And the other lesion in the same case showed RER negative, which showed that genetic heterogeneity was recognized. For clinicopathological factors according to RER status, no significant differences were observed in age, gender, tumor localization and size, histological type, depth of invasion, lymph node metastasis, venous invasion or pTNM classification. In conclusion, it is suggested that the carcinogenic etiology of these two groups may be different from our results.
