Study On The Correlation Between BRAF ^{V600E Gene Mutation And Iodine Intake In Distant Papillary Thyroid Carcinoma}

Objective:To investigate the relationship between BRAFV600E mutation and radioactive iodine (RAI) uptakein distant metastases from papillary thyroid carcinoma(PTC).Methods:From January 2011 to August 2013,73 PTC patients (32 males,41 females, average age 39.6 years) with distant metastases were recruited and divided into two groups (mutation group and wild group) according to the BRAFV600E mutation in primary lesion. The clinical and pathological differences were compared between two groups. The relation between BRAFV600E mutation and RAI uptake capability in distant metastases from PTC as well as its relationship with the change of Thyroglobulin(Tg) after 131I treatment were observed. Statistical analysis was performed with two-sample t test, χ2 test or Fisher exact test.Results:The BRAFV600E mutation rate was 26.0%(19/73) in patients with metastases from PTC. The mean age of mutation group was older than that of the wild-type group (P< 0.05). Nineteen PTC patients had no RAI uptake in the distant metastases, of which 16 belonged to mutation group (84.2%,16/19) and 3 belonged to wild group (5.6%,3/54; χ2=41.17,P<0.05). BRAFV600E mutation group was more likely to have no RAI uptake in the distant metastases (X2=41.17, P<0.05). In the wild group, Tg level decreased in 66.7%(14/21) patients, stabilized in 19.1%(4/21)and increased in 14.3%(3/21) patients,while there was no decrease ofTg in the mutation group(0/9). Two patients had increased Tg level and 7 patients (with no RAI uptake) kept stable in mutation groupConclusions:BRAFV600E mutation is more likely to occur in older patients. PTC patients with primary lesion BRAFV600E mutation may have poor RAI uptake capability in their distant metastases and poor response to 131I treatment. Molecular detection of BRAF mutation might be helpful for choosing PTC with distant metastases and predicting the effect of 131I treatment.