The replication error phenotype (RER+) represents an important new form of genetic alteration characterized by widespread instability in repetitive nucleotide sequences. The aim of this study was to compare the features of RER+ gastric tumours with those of RER+ colonic tumours. RER status was determined by analysis of size alterations in the BAT-26 mononucleotide repeat microsatellite, Twelve of 121 (10 per cent) gastric carcinomas from a low-incidence region were found to he RER+. BAT-26 instability was associated with tumours showing an absence of nodal invasion (p=0.009) and with a trend for improved prognosis, These tumours mere more frequent in older, female patients. Frameshift mutations in mononucleotide repeat sequences within the transforming growth factor-beta receptor II (RII), insulin-like growth factor II receptor (IGFIIR), and BAX genes were observed in 83, 33, and 25 per cent, respectively, of RER+ tumours, Only 1/12 (8 per cent) RER+ tumours contained a p53 gene mutation compared with 29/109 (27 per cent) RER tumours, RER+ gastric carcinomas therefore share several important features with RER+ colonic tumours, including less frequent nodal invasion, improved prognosis, a similar frequency of mutation in growth control genes containing repetitive nucleotide sequences, and a low frequency of mutation of the p53 tumour suppressor gene, Copyright (C) 1999 John Wiley & Sons, Ltd.
|Pages (from-to)||428 - 432|
|Journal||Journal of Pathology|
|Publication status||Published - 1999|