ROS1 Gene Rearrangement by FISH

What is ROS1 gene rearrangement by FISH test?

ROS1 gene rearrangement by FISH detects the split-apart signals in the ROS1 locus, indicating a ROS1 fusion in tumor cells—most commonly in lung adenocarcinoma—so patients can be considered for ROS1‑targeted tyrosine kinase inhibitors.

Why consider ROS1 gene rearrangement by FISH test?

Clinicians should consider ROS1 gene rearrangement test as

• Identifies ROS1 fusions present in approximately 1–2% of NSCLC, enabling use of effective ROS1 TKIs and improving treatment outcomes compared with chemotherapy.
• Provides high analytical confidence; commonly used to confirm positive or equivocal ROS1 immunohistochemistry results due to IHC’s variable specificity.
• It is recommended for lung cancer patients to determine eligibility for targeted therapy.

Who should get this ROS1 gene rearrangement by FISH test?

ROS1 gene rearrangement test is recommended for patients with late-stage non-small-cell lung cancer (NSCLC) adenocarcinoma who have tested negative for EGFR mutations and ALK rearrangements This is because ROS1 rearrangement acts as a target for specific targeted therapies, like crizotinib, which can be effective in treating this type of cancer.

ROS1 gene rearrangement test helps identify patients who could benefit from such treatments, improving their outcomes.

• Patients with diagnosed NSCLC adenocarcinoma
• Patients who are negative for EGFR and ALK alterations
• Patients with specific characteristics

More Information about ROS1 gene rearrangement by FISH test

The fusion activates ROS1 tyrosine kinase signalling, leading to uncontrolled proliferation via pathways and establishing ROS1 as a true oncogenic driver. Prevalence in NSCLC is typically around 1–2%, frequently in younger, never‑smokers with adenocarcinoma histology, defining a distinct molecular subset

Other Names: ROS1 Rearrangement FISH; ROS1 Fusion by FISH, ROS gene Test, ROS1 Gene Assay, Lung canner ROS1 gene