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Prosigna’s analytical validation study demonstrated high precision and reproducibility across multiple qualified laboratories2

Objective: assess 2 aspects of Prosigna’s analytical robustness when used in qualified clinical laboratories: reproducibility when starting from tissue and precision when starting from RNA

Starting from tissue, total standard deviation was only 2.9 Risk of Recurrence (ROR) units across 3 independent sites

  • Reproducibility was assessed by testing a panel of 43 FFPE blocks across 3 sites, including independent H&E review, macrodissection, and RNA isolation by lab personnel at each site
  • Average site-to-site concordance of risk category was >90%, and there were no low-to-high-risk misclassifications or vice versa
  • Average site-to-site concordance of subtype classification was 97%
Analytical validation study overview: reproducibility from tissue
Distribution of test results from the 43 tissue samples across Prosigna Scores and risk categories

Starting from RNA, total standard deviation was <1 ROR unit regardless of testing site, operator, and reagent lot

  • Precision was assessed by testing 5 pooled FFPE breast tumor RNA samples >100 times each
  • RNA samples were run independently at 3 different testing sites by a total of 6 different operators using 3 different reagent lots
  • The range of ROR scores for 108 independent measurements was ≤4 units for each of the 5 sample pools
  • 100% concordance was shown between measured and expected subtype result and risk group
Analytical validation study overview: precision from RNA
Distribution of Prosigna Scores for the 5 RNA pools tested in the RNA precision study
References: 1. Prosigna [Package Insert]. Seattle, WA: NanoString Technologies, Inc; 2013. 2. Nielsen T, Wallden B, Schaper C, et al. Analytical validation of the PAM50-based Prosigna Breast Cancer Prognostic Gene Signature Assay and nCounter Analysis System using formalin-fixed paraffin-embedded breast tumor specimens [published online ahead of print March 13, 2014]. BMC Cancer. doi:10.1186/1471-2407-14-177. 3. Nielsen T, McDonald S, Kulkarni S, et al. Analytical reproducibility of the breast cancer intrinsic subtyping test and nCounter® Analysis System using formalin-fixed paraffin-embedded (FFPE) breast tumor specimens. Poster presented at: 102nd United States and Canadian Academy of Pathology Annual Meeting; March 2-8, 2013; Baltimore, MD. Abstract 2075.