PD-L1 22C3 IHC with Combined Positive Score (CPS) Interpretation, pembrolizumab (KEYTRUDA)
Ordering Recommendation

Use for gastric/GEJ, urothelial, cervical, esophageal squamous cell carcinoma (ESCC), and head and neck squamous cell carcinoma (HNSCC) specimens only. Aid in prediction of response to pembrolizumab (KEYTRUDA) as first-line and/or second-line therapy for patients with gastric/GEJ adenocarcinoma, urothelial carcinoma, cervical carcinoma, esophageal squamous cell carcinoma (ESCC), or head and neck squamous cell carcinoma (HNSCC). Refer to the PD-L1 Testing Algorithm for more information.

1-5 days
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
ARUP Consult®
Disease Topics
Specimen Required
Patient Preparation
Tumor tissue. 
Specimen Preparation
Formalin fix (10 percent neutral buffered formalin) and paraffin embed specimen. Protect paraffin block and/or slides from excessive heat. Transport tissue block or 5 unstained (3- to 5-micron thick sections), positively charged slides in a tissue transport kit (ARUP supply #47808 recommended but not required), available online through eSupply using ARUP Connector contact ARUP Client Services at (800) 522-2787. (Min: 3 slides) If sending precut slides, do not oven bake. 
Storage/Transport Temperature
Room temperature. Also acceptable: Refrigerated. Ship in cooled container during summer months. 
Unacceptable Conditions
Paraffin block with no tumor tissue remaining; specimens fixed in any fixative other than 10 percent neutral buffered formalin. Decalcified specimens. Specimens with fewer than 100 viable tumor cells. Lung specimens. 
Include surgical pathology report and indicate tissue site with the test order. For additional technical details, please contact ARUP Client Services at (800) 522-2787. 
Slides: Ambient: 5 months (Must be stored in the dark); Refrigerated: 5 months (Must be stored in the dark); Frozen: Unacceptable
Paraffin Block: Ambient: Indefinitely; Refrigerated: Indefinitely; Frozen: Unacceptable 
Reference Interval
Interpretive Data
Refer to report.

This test code includes pathologist interpretation. At least 100 viable tumor cells are required for interpretation.
Hotline History
View Hotline History
Component Test Code*Component Chart NameLOINC
2012108PD-L1 Client Block ID57723-9
2013285PDL1 Tissue Source31208-2
2013286Adequacy of Specimen
3000223Combined Positive Score83053-9
3000224PDL1 22C3 IHC Result83052-1
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
  • Merck
  • PD-L1
  • PDL1
  • Pembro