Association Between BRAF V600E and Redifferentiation Therapy in Patients With Radioiodine-refractory Papillary Thyroid Cancer

Papillary thyroid cancer (PTC) is the most common neoplasia in the thyroid gland. The combination of surgery, followed by radioiodine therapy (RIT) and thyroid-stimulating hormone (TSH) suppressive therapy is usually a curative option for differentiated thyroid cancer (DTC). Although DTC has a good prognosis generally, it is problematic when dedifferentiation is suspected and radioiodine refractoriness presumed. One possible therapy option for redifferentiation is the pretreatment with retinoids. From 2008 to 2014 there were 13 patients with PTC who were treated with retinoids after thyroidectomy before a further course of radioiodine. A recent study has shown that the efficacy of Selumetinib, another option for redifferentiation depends on the mutational status of the treated patient. In this retrospective study the investigators looked for a similar association between BRAF V600E and redifferentiation therapy with retinoids. As retinoids have fewer side effects compared to TKI, it is worth performing studies to assess the importance of genetic marker for the response and to estimate the chances of this specific patient collective. BRAF V600E seems to be associated with better long-term response after redifferentiation therapy with 13-cis RA in RAI-R PTC. Therefore, evaluation of BRAF mutational status prior to redifferentiation therapy could be beneficial for predicting response.