Association of CYP2D6*4 gene polymorphism with early papillary thyroid carcinoma

Objectives CYP2D6 is highly polymorphic and a common variant CYP2D6*4 results in the generation of poor metabolizer enzyme. The CYP2D6*4 variant has been associated with altered susceptibility to several cancers. The aim of the present case-control study aims to investigate the association between CYP2D6*4 polymorphism and the risk of papillary thyroid carcinoma (PTC). Materials and methods A study population of 97 cases with PTC and 120 controls were included in the study. Genotyping was done by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method to detect the presence of CYP2D6*4. Results The CYP2D6*4 was associated with significantly increased PTC risk when compared with controls (odds ratio [OR]=1.995, 95% confidence interval [CI]=1.060–3.752, p=0.031). Besides, CYP2D6*4 allele frequency was higher in PTC patients with age ≤50 years when compared to those with age >50 (OR=2.380, 95% CI=1.191–4.755, p=0.013). CYP2D6*4 allele frequency was higher in patients who had encapsulated tumors, but it was not statistically significant (p=0.111). No relationship was found between CYP2D6*4 and PTC variants or between early (I/II) and late (III/IV) tumor stages. Conclusions Our findings indicate that the poor metabolizer CYP2D6*4 genotype may be a risk factor, especially in early PTC development. Further research with larger groups is required for the confirmation of our consequences.