Microsatellite instability in sporadic human breast cancers

Abstract

Human breast‐cancer specimens from 100 patients were analyzed for microsatellite instability (referred to as replication error; RER) at 12 genomic loci on 7 chromosomes, and results were correlated with clinicopathologic characteristics. In 42 of 100 breast‐cancer patients, we investigated whether RER was associated with the amplification of oncogenes and/or suppression of tumor‐suppressor genes. Of the 100 patients, 8 (8%) were RER‐positive at one or more chromosomal loci. The majority of RER‐positive patients had early‐stage disease with ER‐positive tumors, suggesting that RER occurs early in breast tumorigenesis. However, no significant correlation was observed between RER and oncogenes or tumor‐suppressor genes. Thus, the mechanism of RER in sporadic human breast cancer may be independent of the multi‐step carcinogenesis caused by the alterations of oncogenes and tumor‐suppressor genes. © 1996 Wiley‐Liss, Inc.