What the test looks for
Assessment of PD-L1 protein expression by immunohistochemistry.
The result is expressed according to the tumour site: percentage of stained tumour cells (TPS) in lung cancer, combined positive score (CPS) in other tumours. It determines access to certain immunotherapies.
Required sample
- Recent FFPE block, or unstained slides cut less than 2 months ago.
- At least 100 viable tumour cells.
- Pathology report enclosed.