PDL1 (Immunotherapy) Tests

A PD-L1 test uses a sample of cancerous tumor tissue to measure how much of a protein called programmed-death ligand 1 (PD-L1) is found on the cancer cells. Normally, PD-L1 is found on certain healthy cells. It helps keep your immune system from attacking healthy tissue by acting as a kind of 'brake' on your immune system cells (called T-cells).

However, in some cancers, PD-L1 keeps your immune system from attacking cancerous cells. If you have one of these kinds of cancers and high levels of PD-L1, your provider can treat your cancer with immunotherapy (a treatment option that helps your immune system fight cancer). In cancers with high PD-L1 levels, health care providers use a type of immunotherapy called 'immune checkpoint inhibitors.' These medicines stop PD-L1 from binding to your T-cells.

In other words, they 'release the brakes,' allowing your immune system to target and kill cancer cells.

Why this test is done

You may need a PD-L1 test if you've been diagnosed with certain types of cancer that commonly cause high PD-L1 levels. These cancers include:

• Non-small cell lung cancer
• Melanoma
• Hodgkin lymphoma
• Bladder cancer
• Kidney cancer
• Breast cancer
• Head and neck cancer (squamous cell carcinoma)
• Cancer of the esophagus (squamous cell carcinoma)
• Stomach cancer (adenocarcinoma)
• Cervical cancer

Your provider may also order a PD-L1 test to monitor your treatment progress.

How to prepare

Preparations for your test depend on how your tissue sample will be taken. You may need to stop taking certain medicines, such as blood thinners like aspirin, before this test. So, tell your provider about all the medicines and supplements you take.

Don't stop or start taking anything unless your provider tells you to.

Before you get any procedure, you should tell your provider about any recent surgeries or known allergies. You should also tell them if you're pregnant.

If you're having general anesthesia, you will probably need to fast (not eat or drink) for several hours before surgery. If you have general anesthesia or medicine to relax, you may be groggy after the procedure, so plan to have someone take you home.

Ask your provider how to prepare for your test.

Sample type

Tissue/Biopsy

Other names for this test

programmed death-ligand 1, PDLI, PDL-1 by immunohistochemistry (IHC)