Association of iodine intake and BRAFV600E mutation in papillary thyroid carcinoma

Abstract

Objective To investigate the correlation between iodine intake, BRAF mutation in thyroid gland and clinical biologic characteristics in papillary thyroid carcinoma(PTC) cases. Methods A total of 159 PTC patients and 200 healthy controls were enrolled in this study. Urine iodine was tested, BRAFV600E mutation was detected by PCR. The correlation was analyzed between BRAF mutation and iodine intake, BRAF mutation and clinical biologic characteristics of PTC respectively. Results The median urinary iodine (MUI) of the patients and healthy controls was 336 μg/L and 196 μg/L respectively (P=0.004). The overall prevalence of the BRAFV600E mutation in this series of PTC was 63.5%, showing a clear correlation of BRAFV600E mutation with iodine intake (P=0.006). There was no correlation of BRAFV600E mutation with age, gender, tumor size, extrathyroid extension or nodulor goiter in PTC (P>0.05). But there was a significant association of BRAFV600E mutation with lymph node metastasis (P=0.008) and Hashimoto's thyroiditis (P=0.037). Conclusions High iodine intake may be a risk factor for PTC occurrence. In PTC cases, high iodine intake may be a risk factor of BRAFV600E mutation. BRAFV600E mutations increase both in PTC with cervical lymph node metastases and uncoexisting Hashimoto's thyroiditis. Key words: Thyroid neoplasms; Carcinoma, papillary; Risk factors; Iodine