TPS
Also written as: TPS — Tumor Proportion Score
Tumor Proportion Score, measuring the percentage of tumor cells expressing PD-L1 protein.
Full Definition
TPS (Tumor Proportion Score) is a PD-L1 immunohistochemistry scoring method that quantifies the percentage of viable tumor cells showing partial or complete membrane staining. TPS is used primarily in non-small cell lung cancer to guide immune checkpoint inhibitor therapy decisions, with thresholds of ≥1% and ≥50% having distinct clinical implications. TPS scoring focuses specifically on tumor cell PD-L1 expression, excluding immune cells from the calculation. Editors must distinguish TPS from other PD-L1 scoring methods like CPS (Combined Positive Score) and ensure threshold values are accurately reported in treatment recommendations.
Usage
Usage note: Capitalize as TPS. Always include percentage value and specify threshold criteria used for treatment decisions.
In Context
- "The tumor demonstrated TPS of 85%, supporting first-line pembrolizumab monotherapy." — lung cancer treatment plan
- "PD-L1 expression was assessed using TPS methodology with a threshold of ≥50% for biomarker positivity." — clinical trial protocol