Relationship between BRAFv600E mutation and radioactive iodine uptake in distant metastases from papillary thyroid cancer / 中华核医学与分子影像杂志

ABSTRACT

Objective To investigate the relationship between V-raf murine sarcoma viral oncogene homolog B1 (BRAF)v600E mutation and radioactive iodine (RAI) uptake in distant metastases from papillary thyroid cancer(PTC).Methods From January 2011 to December 2012,40 PTC patients (21 males,19 females,average age 39.8 years) with distant metastases were recruited and divided into mutation group and wild group according to the BRAFv600E mutation in primary lesions.The clinical,pathological and serological differences were compared between the two groups.The relationship between BRAFv600E mutation and RAI uptake capability in distant metastases from PTC,as well as its relationship with Tg change after 131I treatment were investigated.Statistical analysis was performed with two-sample t test,x2 test or Fisher exact test.Results The BRAFv600E mutation rate was 30.0％ (12/40) in patients with metastases from PTC.There was no significant difference in clinical,pathological and serological features between mutation group (n =12) and wild group (n=28; tfrom-0.533 to 1.728,x2from-1.951 to 1.088,all P＞0.05).Twelve PTC patients had no RAI uptake in the distant metastases,of which 10 belonged to mutation group (83.3％,10/12) and 2 belonged to wild group (7.1％,2/28; x2=19.734,P＜0.05).BRAFv600E mutation group was more likely to have no RAI uptake in the distant metastases.Tg change after 131I treatment in 30 patients were analyzed.In the wild group,Tg level decreased in 66.7％ (14/21) patients,stabilized in 19.0％ (4/21)and increased in 14.3％ (3/21)patients.While there was no decrease of Tg in the mutation group (0/9).Two patients had increased Tg level and 7 patients (with no RAI uptake) kept stable in mutation group.Conclusions Due to poor RAI uptake capability in PTC patients with BRAFv600E mutation,both primary and metastatic sites may have poor response to 131I treatment.Molecular detection of BRAFv600E mutation might be helpful for choosing PTC with distant metastases and predicting the effect of 131 I treatment.