Ordering Recommendation

Use for gastric/gastroesophageal junction (GEJ) adenocarcinomas, urothelial carcinoma, cervical carcinomas (squamous cell carcinomas and adenocarcinomas), esophageal squamous cell carcinoma (ESCC), head and neck squamous cell carcinoma (HNSCC), and triple-negative breast cancer (TNBC) specimens only, to aid in prediction of response to pembrolizumab (KEYTRUDA). Refer to the PD-L1 Testing Algorithm for more information.

Mnemonic
22C3 GAST
Methodology

Immunohistochemistry

Performed

Mon-Fri

Reported

1-5 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect

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. Non-indicated tumor types, including non-small cell lung carcinomas.

Remarks

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.

Stability

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.  

Compliance Category

FDA

Note

This test code includes pathologist interpretation. At least 100 viable tumor cells are required for interpretation.

Hotline History
N/A
CPT Codes

88360

Components
Component Test Code* Component Chart Name LOINC
2012108 PD-L1 Client Block ID 57723-9
2013285 PDL1 Tissue Source 31208-2
2013286 Adequacy of Specimen
3000223 Combined Positive Score 83053-9
3000224 PDL1 22C3 IHC Result 83052-1
* 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.
Aliases
  • Merck
  • PD-L1
  • PDL1
  • Pembro
PD-L1 22C3 IHC with Combined Positive Score (CPS) Interpretation, pembrolizumab (KEYTRUDA)