RET Gene (10q11.21) Rearrangement FISH

What is RET gene rearrangement test?

RET gene rearrangement testing is a molecular diagnostic test used to detect fusions (rearrangements) involving the RET gene, which can drive the growth of certain cancers. Detecting a RET fusion is critical because it identifies patients who may benefit from targeted therapy with RET inhibitors.

Why consider RET gene rearrangement test?

• Identify Eligibility for Targeted Therapy - Patients with RET fusion–positive cancers can be treated with selective RET inhibitors.
• RET testing is recommended in clinical guidelines (e.g., NCCN, ESMO) for: Non-Small Cell Lung Cancer (NSCLC), Papillary Thyroid Cancer, Medullary Thyroid Cancer (MTC) and other cancers.

Who should get tested for RET gene rearrangement test?

• Patients with advanced or metastatic lung adenocarcinoma as part of comprehensive biomarker testing, especially when negative for other drivers (EGFR, ALK, ROS1) or when clinical-pathologic features suggest a kinase fusion.
• Patients with papillary thyroid carcinoma or other tumors where RET fusions are implicated, to guide consideration of RET-targeted therapy or trials.

More Information about RET gene rearrangement test

A RET gene rearrangement (or fusion) happens when the RET gene fuses with another gene (e.g., KIF5B, CCDC6). This fusion leads to abnormal RET protein activity, which drives cancer growth. It’s considered an actionable mutation, meaning there are FDA-approved drugs that specifically target RET fusion-positive cancers.

OTHER NAMES: RET fusion, tissue, RET rearrangement by FISH, RET fusion by NGS (tissue), RET (10q11) break-apart FISH, RET gene fusion analysis (FFPE)