1. Intra- and Interlaboratory Reproducibility of the Sensitivity to Endocrine Therapy Assay for Stage II/III Breast Cancer
- Author
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Christos Hatzis, John G. Howe, Veerle Bossuyt, W. Fraser Symmans, Brian Leyland-Jones, Brandon Young, Tiffany Foli, Fengmin Zhao, Lili Du, and Rosanna Lau
- Subjects
Oncology ,medicine.medical_specialty ,Intralaboratory ,business.industry ,Biochemistry (medical) ,Clinical Biochemistry ,Endocrine therapy ,Reproducibility of Results ,Breast Neoplasms ,Prognosis ,medicine.disease ,Random effects model ,Breast cancer ,Cohen's kappa ,Concordance correlation coefficient ,Internal medicine ,Biomarkers, Tumor ,medicine ,Humans ,Female ,Stage (cooking) ,Receptors, Progesterone ,business ,Kappa ,Aurora Kinase A - Abstract
Background The sensitivity to endocrine therapy assay (SET2,3) predicts treatment outcomes in Stage II-III breast cancer. SET2,3 measures transcription related to estrogen and progesterone receptors (SETER/PR index) and the molecular subtype (RNA4: ESR1, PGR, ERBB2, AURKA) from formalin-fixed paraffin-embedded (FFPE) tissue sections. Methods We designed a nested study across 3 pathology laboratories, each testing 60 breast cancers twice in controlled batches. Laboratories macrodissected and directly homogenized the unstained FFPE tumor sections, then performed the QuantiGene Plex bead-based hybridization assay. SET2,3 was calculated centrally using predefined statistical R-scripts and applying pre-defined cutpoints. Concordance correlation coefficient (CCC) was calculated from continuous measurements and Kappa statistic from categorical results. A mixed-effects model estimated contributions to bias (fixed effects) and variance (random effects) from the replicated design. Results Intralaboratory (CCC 0.96–0.99) and interlaboratory (CCC 0.98–0.99) SET2,3 results were concordant, with rates of agreement for high/low categorization within (Kappa 0.83–0.93) and between laboratories (Kappa 0.87–0.88). The relative contributions to overall variance of SET2,3 measurements were 96.90% from biological differences between cancers, 0.67% from interlaboratory variability, and 2.44% from residual causes including intralaboratory replicates. Similar results were obtained with SETER/PR, the baseline prognostic index calculated using pathological or clinical tumor and nodal staging information, and the 4 individual genes (ESR1, PGR, ERBB2, and AURKA). Conclusion Intra- and interpathology laboratory measurements of SET2,3 and its components were highly reproducible when tested from FFPE tumor sections.
- Published
- 2021
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