Relationship between BRAFV600E mutation and metastasis after thyroidectomy in papillary thyroid carcinoma with different recurrence risk stratification

Objective To investigate the relationship between V-raf murine sarcoma viral oncogene homologue B1 (BRAF)V600E mutation and metastasis after thyroidectomy in papillary thyroid carcinoma (PTC) with different recurrence risk stratification. Methods From March 2014 to September 2017, 134 PTC patients (45 males, 89 females; age: 16-72 years) who underwent 131I treatment in the Department of Nuclear Medicine of Liaocheng People′s Hospital and had undergone BRAFV600E mutation detection were retrospectively analyzed. The recurrence risk during surgery was divided into 3 levels: low-, medium- and high-risk. Each recurrence risk group was divided into 3 subgroups according to the postoperative follow-up results: non-metastasis group, cervical lymph node metastasis group and pulmonary metastasis group. BRAFV600E mutation rates in different groups were compared (χ2 test). Results The BRAFV600E mutation rate was 55.22%(74/134) in 134 PTC patients. The mutation rates were not significantly different in the 3 metastasis subgroups for low-risk patients (n=46; χ2=2.39, P>0.05). In medium-risk patients (n=47), the mutation rate in neck lymph node metastasis group (16/19) was higher than that in pulmonary metastasis group (3/8) and non-metastasis group (25.00%, 5/20; χ2 values: 5.89 and 13.75, both P 0.05). In high risk patients (n=41), the mutation rate in neck lymph node metastasis group (85.00%, 17/20) was higher than that in the pulmonary metastasis group (5/13) and non-metastasis group (1/8; χ2 values: 7.68 and 13.08, both P 0.05). Conclusion The BRAFV600E mutation is closely related to neck lymph node metastasis after operation in middle- and high-risk patients with PTC, but it does not significantly increase the probabilities of neck lymph node metastasis in low-risk patients and pulmonary metastasis in low-, medium- and high-risk patients. Key words: Thyroid neoplasms; Neoplasms recurrence, local; Neoplasm metastasis; Proto-oncogene protein B-raf; Mutation