IMMUNOHISTOCHEMISTRY, ALK-1

What this test checks

Detects ALK (Anaplastic Lymphoma Kinase) protein expression in tumour cells. ALK rearrangements occur in anaplastic large cell lymphoma (ALCL) and ALK-positive non-small cell lung cancer — both of which respond to ALK inhibitor drugs.

Why do people get this test?

ALK-positive lung cancer and ALCL are two of the most responsive cancers to targeted therapy. ALK inhibitors (crizotinib, alectinib) produce dramatic responses in ALK-positive tumours — making this test potentially life-changing.

When you should consider this test

• When classifying anaplastic large cell lymphoma
• When lung cancer is being tested for ALK rearrangement for targeted therapy
• As a screening test before confirming with FISH or molecular testing

How to prepare

No preparation needed — performed on biopsy or surgical tissue.