Genomic instability in colorectal cancers in Turkey

Area of Science:

• Oncology
• Genetics
• Molecular Biology

Background:

• Microsatellite instability (MSI) is observed in a subset of colorectal cancers globally.
• Previous studies have reported MSI frequencies in North America, Europe, and Japan.

Purpose of the Study:

• To investigate the frequency and characteristics of microsatellite instability in colorectal cancers from Turkish patients.
• To compare MSI findings in Turkish patients with those reported in other populations.

Main Methods:

• Analysis of 88 colorectal cancer samples from Turkish patients.
• Testing of five microsatellite loci (1 mononucleotide and 4 dinucleotide repeat regions).
• Identification of tumors displaying replication errors (RERs) using at least two markers.

Main Results:

• Eight tumors (9%) exhibited microsatellite instability (replication errors).
• A significantly higher frequency of MSI was observed in right-sided tumors compared to left-sided tumors.
• The RER phenotype was slightly more prevalent in younger patients (<50 years) than older patients (13% vs. 8%).
• No association was found between sex and genomic instability.
• The observed MSI frequency of 9% in Turkish patients is lower than the 12%-16% reported in other countries.

Conclusions:

• Microsatellite instability occurs in a subset of Turkish colorectal cancer patients.
• Tumor location (right-sided) and patient age are potential factors associated with MSI in this cohort.
• Further research is warranted to understand the variations in MSI frequencies across different ethnic and geographic populations.