skip to main content

PD-L1 TPS vs CPS — SCE Medical Oncology MCQ

Instant feedback + full explanation. One question, done properly.

EasyLung CancerPD-L1 TPS vs CPSSCE Medical Oncology

A 65-year-old man with NSCLC asks about the difference between PD-L1 TPS and CPS scoring. His report shows PD-L1 TPS 10% but CPS 15. What does each measure?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: E — TPS (Tumour Proportion Score) counts only PD-L1-positive TUMOUR cells / total tumour cells; CPS (Combined Positive Score) counts PD-L1-positive tumour cells + lymphocytes + macrophages / total tumour cells — TPS is used in NSCLC; CPS is used in gastric, cervical and other cancers

PD-L1 scoring differs by assay and cancer type: TPS (tumour proportion score) = PD-L1+ tumour cells / total tumour cells × 100%. Used in NSCLC (22C3 assay for pembrolizumab). CPS (combined positive score) = (PD-L1+ tumour + immune cells) / total tumour cells × 100. Used in gastric (CPS ≥5), cervical (CPS ≥1), TNBC (CPS ≥10), HNSCC (CPS ≥1). IC (immune cell score) = PD-L1+ immune cells / tumour area. Used for atezolizumab. Understanding which score applies to which indication is essential for correct treatment selection.

Reference: ESMO 2024 Biomarker Guidelines; NICE TAs