V-raf murine sarcoma viral oncogene homolog B1 V600E mutation and urinary iodine concentration in papillary thyroid carcinoma

Abstract

Objective To investigate the V-raf murine sarcoma viral oncogene homolog B1 (BRAF) V600E mutation and urinary iodine concentration in papillary thyroid carcinoma (PTC) and the relationship with clinicopathological features. Methods Polymerase chain reaction (PCR) and gene sequencing were performed to detect BRAF V600E mutation in 110 cases of PTC, 47 cases of nodular goiter and 26 of thyroid adenoma thyroid tissues. Simultaneously, the urinary iodine concentration was determined. The relationship between BRAF V600E mutation and urinary iodine concentration with clinicopathological features was studied. Results In 183 cases, BRAF V600E mutation was detected in 54 out of 110 PTC cases with a detection rate of 49% (χ2=50.838, P=0.000). BRAF V600E mutation was negative in nodular goiter and thyroid adenoma. BRAF V600E mutation in PTC was positively correlated with extra-thymidal extension (χ2=6.031, P=0.014), but not with gender (P=0.363), age (P=0.360), tumor number (P=0.593), tumor size (P=0.497), lymph nodal metastasis (P=0.554) and pTNM staging (P=0.785). The excessive iodine intake rate in PTC patients was 79%, obviously higher than that in nodular goiter (66%) and thyroid adenoma (58%) with significant difference (χ2=6.288, P=0.043). The urinary iodine concentration in PTC was negatively correlated with gender (P=0.187), age (P=0.138), tumor number (P=0.571), tumor size (P=0.454), extra-thymidal extension (P=0.345), lymph nodal metastasis (P=0.248) and pTNM staging (P=0.792). The BRAF V600E mutation was not associated with the concentration of iodide in the PTC (χ2=0.019, P=0.891). Conclusion BRAF V600E mutation was a common molecular event and may increase the ability of invasion in PTC. BRAF V600E mutation was a specificity marker in the diagnosis of PTC. The urinary iodine concentration in PTC was significantly higher than that in the benign thyroid nodule diseases. Key words: V-raf murine sarcoma viral oncogene homolog B1 gene; Mutation; Urinary iodine concentration; Papillary thyroid carcinoma