Circulating BRAF may aid in papillary thyroid cancer diagnosis, follow-up

http://www.healio.com/endocrinology/thyroid/news/online/%7B51f45093-16a4-4afb-a643-e14a26bc358c%7D/circulating-braf-may-aid-in-papillary-thyroid-cancer-diagnosis-follow-up

Pupilli C. J Clin Endocrinol Metab. 2013;doi:10.1210/jc.2013-1072.  July 3, 2013 

 The evaluation of circulating BRAF V600E has the potential for use in the diagnosis and follow-up of patients with papillary thyroid carcinoma, according to researchers in Italy.

To determine whether the BRAF V600E mutated allele in cell-free DNA has a role in the diagnosis and follow-up of papillary thyroid carcinoma, researchers detected the allele and quantified it by an allele-specific real-time quantitative polymerase chain reaction assay in plasma from 103 patients affected by nodular goiter. Forty-nine healthy patients and 16 patients with non-nodular thyroid diseases were included as controls for the study.

The percentage of circulating BRAF V600E was significantly different between patients and controls and throughout different cytological categories of ultrasound-assisted fine needle aspiration (FNA). Specifically, percentages were higher among patients with follicular lesions (18.7%; P<.001) and those considered suspicious of malignancy (27.1%; P=.001) vs. controls.

Further, patients with a histopathological diagnosis of papillary thyroid carcinoma displayed a greater percentage of circulating BRAF V600E (P=.035) vs. those with benign histology, according to data.
Blood was drawn from 19 patients 3 to 6 months after surgery and after radioactive iodine treatment when necessary. Among these, circulating percentages of BRAF V600E were significantly lower than in presurgical samples (P<.001).

Using the receiver operating characteristic curve analysis, researchers also reported that the diagnostic performance of circulating BRAF V600E resulted in an area under the curve of 0.797, with maximum specificity of 65% and sensitivity of 80%. They assessed the predictive value of BRAF V600E in patients with follicular lesions; the positive predictive value was 33% and the negative predictive value was 80%.

“The use of BRAF V600E as a circulating marker could have several important clinical applications. In the diagnostic setting, it would integrate the data obtained from cytological analysis of FNA, providing more complete information in particular cases such as multinodular goiters where it is not possible to sample all nodules by FNA,” researchers wrote. “The availability of circulating markers could play an important role also in the short- and long-term follow-up of patients with previous thyroid cancer.” 

Further research is warranted before this can be implemented in clinical settings, they wrote.
Disclosure: The researchers report no relevant financial disclosures.