ALK (D5F3) IHC reflex to FISH for NSCLC

ALK (D5F3) Reflex FISH Overview

ALK is a protein that is normally found in low levels in many different tissues. However, in some types of cancer, ALK is rearranged and produced at high levels. This can lead to the uncontrolled growth of cancer cells. The ALK (D5F3) IHC (immunohistochemistry) test is most commonly used to diagnose non-small cell lung cancer (NSCLC). NSCLC is the most common type of lung cancer, and about 5% of NSCLC cases have ALK rearrangements. The ALK (D5F3) IHC test can also be used to diagnose other types of cancer, such as lymphoma and inflammatory myofibroblastic tumor.

The ALK (D5F3) Reflex FISH test is a comprehensive diagnostic procedure that combines immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) to accurately detect the presence of anaplastic lymphoma kinase (ALK) gene rearrangements in solid tumours, particularly in non-small cell lung cancer (NSCLC). This test is crucial for identifying patients who may benefit from targeted therapy with ALK tyrosine kinase inhibitors (TKIs).

The initial step involves using the D5F3 antibody in an IHC assay to detect ALK protein expression in tumour cells. If the IHC results are equivocal or positive, a FISH test is performed to confirm the presence of ALK gene rearrangements. This dual approach ensures a high level of accuracy in identifying patients with ALK-positive tumours, enabling healthcare providers to make informed decisions regarding personalised treatment plans.