Comparison and Clinical Validation of Three ERCC1 Antibodies in Head and Neck Squamous Cell Carcinoma (HNSCC)
Melissa C Austin, Brenda F Kurland, Renato G Martins, Julie E Bauman, Rodney A Schmidt. University of Washington Medical Center, Seattle, WA; Fred Hutchinson Cancer Research Center, Seattle, WA; University of Pittsburgh Cancer Institute, Pittsburgh, PA
Background: The DNA repair endonuclease excisional cross-complementing group 1 (ERCC1) protein is crucial for repair of interstrand crosslinks induced by platinum chemotherapy. ERCC1 expression predicts clinical benefit from platinum chemotherapy in non-small cell lung cancer and HNSCC, but the specificity of the [8F1] antibody used in the original studies has been questioned. Because new reagents have become available, we evaluated three ERCC1 antibodies for prognostic utility and ease of interpretation.
Design: Optimized immunohistochemistry (IHC) conditions were established against controls for Neomarkers [8F1], OriGene [4F9], and Santa Cruz [FL297] antibodies. IHC was performed on 90 pre-treatment biopsy samples in patients with HNSCC subsequently treated with cisplatin-radiotherapy. ERCC1 expression was described by H-score (weighted percentage of cells demonstrating nuclear staining x staining intensity). The primary endpoint was ability to predict progression free survival (PFS) with a secondary endpoint of qualitative ease of interpretation.
|Antibody||N||Decreased/Normal (H<2.25)||Increased (H>2.25)|
|[8F1]||90||48 (53%)||42 (47%)|
|[4F9]||88||40 (46%)||48 (54%)|
|[FL297]||88||48 (55%)||40 (45%)|