High frequency of microsatellite instability in sporadic colorectal cancer patients in Iran.

Microsatellite instability in sporadic colorectal cancer patients was assessed, and the clinicopathological associations were evaluated in northeastern Iran, which is a high-risk region for gastrointestinal malignancies. Microsatellite instability (MSI) status of tumoral tissue, compared to normal tissue, was assessed with a standard panel of MSI markers on paraffin-embedded surgically resected tissues from 67 consecutive sporadic colorectal cancer patients. Eleven of the patients were under 40 years old.