Frequent microsatellite instability in oral cancer

In oder to confirm whether microsatellite instability (MI) contributes to oral carcinogenesis, we studied 30 unrelated patients with oral cancer by PCR-MI assay with 14 microsatellite markers. MI was detected in 60% of 30 primary tumors. Tn particular, 12 of these cases presented at least two loci with MI, which were considered as patients with replication error (RER). Moreover, an additional MI, which was not observed in the primary tumor and normal tissue, was observed in one lymph node metastasis. We found significant correlation between RER and lymph node metastasis. These results suggest that RER is a common event in the oncogenesis of oral cancer and may be correlated with the progression of this disease.