BRAF mutation in papillary thyroid carcinoma: predictive value for long-term prognosis and radioiodine sensitivity.

OBJECTIVES

BRAF pV600E mutation is the most common oncogenic event and the most specific mutation for papillary thyroid carcinoma (PTC). Many studies over the last decade have shown a direct relationship between BRAF mutation and aggressive tumour characteristics, resulting in poor prognosis. However, several recent studies have suggested that BRAF mutation is not associated with poor prognosis of PTC. The present study was designed to evaluate the association between BRAF mutation with clinicopathological factors and tumour recurrence.

MATERIAL AND METHODS

In this retrospective study, BRAF mutation status was examined by direct sequencing on paraffin-embedded tumour specimens from 46 patients undergoing surgery for PTC in our institution from 1985 to 2000. The relationship between BRAF mutation and gender, advanced age, extrathyroid extension, multifocal tumour, cervical lymph node metastasis, tumour size and advanced pT stage of PTC and its predictive role for the risk of tumour recurrence were investigated with a median follow-up of 10.1 (±6.5)years.

RESULTS

BRAF mutation was detected in 20 of the 46 patients (43.5%) included in the study. No statistically significant correlation was demonstrated between the presence of BRAF mutation and the various clinicopathological factors studied. No significant difference in tumour recurrence rate or radioiodine sensitivity was observed between the two subgroups: mutant BRAF and wild-type BRAF.

CONCLUSION

Although BRAF mutation appears to play a role in local tumour progression, it is not a risk factor for poor prognosis or tumour recurrence in PTC.