Abstract 701P
Background
Overexpression of the mesenchymal epithelial transition factor (MET) protein represents a potential therapeutic target in lung cancer, underscoring the importance of accurate detection for effective treatment. Various assays are utilized for MET immunohistochemistry (IHC) testing in clinical research and practice, but the lack of research on their detection performance significantly limits the availability and standardization of testing. This study is the first to evaluate the concordance of various MET IHC assays in lung adenocarcinoma (LUAD).
Methods
One hundred formalin-fixed and paraffin-embedded tumour tissues (50 surgical and 50 biopsy) from Chinese LUAD patients between 2022∼2024 were enrolled. Retrospective IHC detection was performed using four MET antibodies—SP44, LBP4, D1C2, MXR039 with corresponding visualization and platforms. Slides were independently evaluated by two experienced pathologists according to Clinical Score, with strong staining in ≥50% of tumour cells defined as positive. Overall consistency, sensitivity and specificity were assessed with SP44 as a reference.
Results
Twenty-four samples were verified as positive using SP44. Using SP44 as a reference, the overall consistency of LBP4, D1C2, and MXR039 staining was 98% (98/100), 95.00% (95/100), and 95.00% (95/100), while sensitivity rates were 100.00% (24/24), 83.33% (20/24), 95.83% (23/24) and specificity rates were 97.37% (74/76), 98.68% (75/76), 94.74% (72/76), respectively.
Conclusions
Our results show good concordance in four assays, which provides more options for clinical MET IHC detection in LUAD. Subtle variations in staining performance of different assays and subjective nature of pathological evaluation may contribute to the discrepancies in staining evaluation results, which highly prompts labs to establish a standard operating procedure and enhance interpretation training for each assay.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.