November 22, 2011

Type of Thyroid Cancer May be More Therapeutically Vulnerable

(Ivanhoe Newswire) — Papillary carcinoma is the most common type of thyroid cancer, and about one fourth of these carcinomas have mutations in the BRAF gene. These mutations are most common in high-grade carcinomas, in particular, the ones that resist standard treatments. According to researchers at Memorial Sloan-Kettering Cancer Center, New York, exploiting the expression of BRAF by the resistant cancers could be a therapeutic advantage.

Despite the prevalence of BRAF mutations in papillary carcinoma it has remained unclear how dependent thyroid cancers are on BRAF expression. Fagin and colleagues first showed that thyroid tumors in mice expressing one of the most commonly detected BRAF mutations in human papillary thyroid carcinomas were exquisitely dependent on BRAF for viability. Of therapeutic significance, treating thyroid tumor—bearing mice with drugs that inhibited the BRAF signaling pathway rendered the tumor cells susceptible to a therapeutic dose of RAI. Fagin and colleagues therefore suggest that their data provide rationale for clinical trials testing whether such drugs can restore the efficacy of RAI therapy in patients with papillary thyroid carcinomas expressing BRAF mutations.

SOURCE: Journal of Clinical Investigation, published online November 21, 2011