title: mRNA BRAF expression helps to identify papillary thyroid carcinomas in thyroid nodules independently of the presence of BRAFV600E mutation.
abstract: Literature has consistently shown associations of BRAFV600E mutation with papillary thyroid cancer clinical features. However, the clinical utility of BRAF expression has not been clinically explored so far. We studied 67 thyroid nodules (32 benign nodules and 35 PTC cases). BRAF mRNA expression levels measured by a quantitative real-time PCR and a PCR-RFLP were used to identify BRAFV600E mutation. BRAF mRNA expression was significantly higher in malignant (198.2±373.9 AU) than in benign (4.1±6.9 AU) nodules (p<0.0001). BRAF expression identified malignancy with a sensitivity of 80.6%, specificity of 77.1%, positive predictive value of 75.8%, and negative predictive value of 81.8%. A cut-point of 4.712, identified by the ROC curve, was able to sort out malignant nodules with an accuracy of 78.8%. Although we did not find any correlation between the presence of BRAF V600E mutation and clinical or tumor features such as age (p=0.309), gender (p=0.5453), ethnicity (p=0.9820), tumor size (p=1.000), multifocality (p=0.2530) or mRNA levels (p=0.7510), the study power for BRAF expression and diagnosis (99%; FPRP=0.85) indicated that data is noteworthy despite the relative small number of patients investigated. We concluded that BRAF mRNA expression may help to identify PTC among thyroid nodules independently of the presence of BRAFV600E mutation.
authors: Laboratory of Cancer Molecular Genetics, Faculty of Medical Sciences, University of Campinas, São Paulo, Brazil.
authors: Priscila Pereira Costa
authors: PP
authors: Araujo
authors: Marjory Alana
authors: MA
authors: Marcello
authors: Alfio Jose
authors: AJ
authors: Tincani
authors: Ana Carolina Trindade
authors: AC
authors: Guilhen
authors: Elaine Cristina
authors: EC
authors: Morari
authors: Laura Sterian
authors: LS
authors: Ward
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics; D044963:Biopsy, Fine-Needle; D002277:Carcinoma / Q000175:diagnosis* / Q000235:genetics; D002291:Carcinoma, Papillary; D003937:Diagnosis, Differential; D005260:Female; D015870:Gene Expression; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011237:Predictive Value of Tests; D011446:Prospective Studies; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism*; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000235:genetics; D016606:Thyroid Nodule / Q000175:diagnosis* / Q000235:genetics
chemical_list: D014408:Biomarkers, Tumor; D012333:RNA, Messenger; C482123:Braf protein, rat; D048493:Proto-Oncogene Proteins B-raf