PD-L1 expression
Quantitative measurement of programmed death-ligand 1 protein on tumor cells, used to predict immunotherapy response.
Full Definition
PD-L1 expression refers to the quantitative assessment of programmed death-ligand 1 protein displayed on tumor cell surfaces, typically measured as a percentage through immunohistochemical staining. This biomarker serves as a predictive tool for patient response to immune checkpoint inhibitor therapies. Expression levels are reported using standardized scoring systems and influence treatment selection in multiple cancer types. The measurement requires specialized pathology expertise and validated assays for accurate clinical interpretation.
Usage
Usage note: Always hyphenate when used as compound modifier; capitalize all letters in PD-L1.
In Context
- "The pathology report indicated PD-L1 expression of 85% in tumor cells." — Molecular pathology report
- "Patients with high PD-L1 expression showed improved response to pembrolizumab." — Clinical trial manuscript