Polymorphisms in base excision repair genes and thyroid cancer risk

Area of Science:

• Genetics and Molecular Biology
• Cancer Research
• Endocrinology

Background:

• Thyroid cancer (TC) is the most common endocrine malignancy.
• Radiation exposure, especially in childhood, is a known risk factor for TC.
• The Base Excision Repair (BER) pathway is crucial for repairing DNA damage from genotoxic agents like radiation.

Purpose of the Study:

• To assess the role of six BER gene polymorphisms in modifying individual susceptibility to non-familial thyroid cancer.
• To investigate potential associations between specific BER polymorphisms and TC risk, including histological subtypes.

Main Methods:

• A hospital-based case-control study was conducted.
• 109 TC patients (treated with iodine-131) and 217 matched controls were analyzed.
• Six BER polymorphisms (XRCC1, OGG1, APEX1, MUTYH, PARP1) were genotyped.

Main Results:

• No significant association was found between most studied BER polymorphisms (XRCC1, OGG1, APEX1, PARP1) and overall TC susceptibility.
• A near-significant association was observed between MUTYH Gln335His heterozygosity and an increased risk of papillary thyroid cancer.
• This is the first study to evaluate the MUTYH Gln335His polymorphism in relation to TC susceptibility.

Conclusions:

• The studied BER polymorphisms, except possibly MUTYH Gln335His, do not appear to significantly influence susceptibility to non-familial thyroid cancer.
• The potential role of MUTYH Gln335His in papillary TC risk warrants further investigation in larger cohorts due to the modest sample size.
• Future research should focus on larger populations to validate these findings and explore the predictive utility of the MUTYH Gln335His genotype.