Thyroid cancer (TC) is the most common type of endocrine tumors and its incidence has been rising in recent decades. It is a heterogeneous disease with widely varying mutation profiles in different patients. However, specific mutations in genes such as BRAF, KRAS, NRAS, HRAS, and RET are commonly associated with thyroid cancer.

The BRAF (v-Raf murine sarcoma viral oncogene homolog B1) gene encodes a protein involved in cell signaling. The BRAF V600E mutation is the most common genetic alteration in thyroid cancer, particularly in papillary thyroid carcinoma (PTC) which is the most common type of thyroid cancer.

KRAS (Kirsten Rat Sarcoma Viral Oncogene Homolog), NRAS (neuroblastoma RAS viral oncogene homolog), and HRAS (Harvey rat sarcoma viral oncogene homolog) genes are part of the RAS family, which plays a role in cell growth and differentiation. Mutations in KRAS, NRAS, and HRAS are less common in thyroid cancer compared to the BRAF mutation. RAS mutations are often found in follicular thyroid carcinoma (FTC) and poorly differentiated thyroid carcinoma (PDTC).

The RET (rearranged during transfection) gene provides instructions for making a receptor tyrosine kinase involved in cell signaling. Mutations in RET are associated with medullary thyroid carcinoma (MTC), a rare type of thyroid cancer. In some cases, these mutations can also be found in familial forms of PTC.

The presence of these mutations can influence the treatment and prognosis of thyroid cancer patients. For instance, patients with BRAF V600E mutation-positive thyroid cancer may be eligible for targeted therapies, such as BRAF inhibitors. Molecular testing, including mutational analysis, is often performed on thyroid cancer tissue for the purpose of classification, and to guide treatment decisions and predict the course of the disease.