Microsatellite instability in latent prostate cancers

Forty-seven latent prostate cancers obtained from 46 Japanese men were examined for microsatellite instability (MSI). This study with examination at 23 microsatellite loci revealed replication error (RER) in II of the 47 cases (23%), 4 of them showing RER with 2 loci that was defined as MSI. Histological grade was significantly associated with RER; 9 of the 11 RER positive cases were of infiltrative type, and the 4 of them exhibiting MSI were all poorly differentiated. While the frequency of MSI in latent prostate cancer was lower than in clinical cases, it was found in the more aggressive lesions thought most likely to develop into clinical cancers.