Association of FOXO1 Rs17592236 Polymorphism and Tumor Size in Papillary Thyroid Carcinoma.

Background: A group of transcription factors involved in several cellular processes like cell growth, proliferation, cell cycle, differentiation and apoptosis which are critical to the cell biology of cancer is Forkhead Box O (FOXO) family. FOXOs are known as putative tumor suppressors. FOXO1 is a member of FOXO family which its abnormal expression or function has been indicated to promote cell proliferation and tumorigenesis. The probable effects of FOXO1 rs17592236 polymorphism on Papillary thyroid carcinoma (PTC) and its clinical findings were evaluated. Methods: In total, 156 PTC patients and 158 healthy subjects were participated in the study. Genotyping of FOXO1 rs17592236 polymorphism was carried out using RFLP-PCR method. Results: There was no association between the FOXO1 rs17592236 polymorphism and PTC in codominant, recessive, dominant, overdominant, and log-additive models. The frequency of rs17592236A allele was 13% in PTC and 17% in control group and were not statistically significant (p= 0.15). The analysis of the relationship between FOXO1 rs17592236 polymorphism and clinical specifications of papillary thyroid carcinoma demonstrated no significant relationship between rs17592236 polymorphism and PTC in different ages (< 40 and≥ 40), gender (male/female), extrathyroidal expansion, N stage, vascular invasion and capsular invasion in PTC patients. There was a relationship between FOX1 rs17592236 polymorphism and a larger tumor size (≥ 1 cm) only in log-additive model (OR= 2.96, 95% CI= 0.88-9.98; p= 0.04). Discussion: FOXO1 rs17592236 polymorphism was not associated with PTC; however, this variant was associated with a larger tumor size (≥ 1 cm) only in log-additive model.