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Table 3 Tumor specimens for which interobserver disagreement arose regarding the results of fluorescence in situ hybridization.

From: HER2 testing on core needle biopsy specimens from primary breast cancers: interobserver reproducibility and concordance with surgically resected specimens

CNB specimens
Code Final judgment HER2/CEP17by 1st counts HER2/CEP17by 2nd counts
   Obs. A Obs. B Average Obs. A Obs. B Average
B61 Amplification 2.71 1.55 2.13 2.55 1.88 2.22
B62 Amplification 2.35 1.88 2.12 2.44 2.07 2.26
B87 Amplification 1.94 2.44 2.19 3.50 2.38 2.44
Surgically resected specimens
Code Final judgment HER2/CEP17 by 1st counts HER2/CEP17 by 2nd counts
   Obs. A Obs. B Average Obs. A Obs. B Average
S67 Amplification 2.67 1.81 2.24 ND ND -
  1. HER2 amplification was defined as positive, equivocal, and negative when the HER2/CEP17 ratio was more than 2.2, between 1.8 and 2.2, and less than 1.8, respectively. For the surgically resected specimen, the average of the HER2/CEP17 ratio (2.24) between observers (2.67 and 1.82) was adopted, because the second count was not done (ND). Obs., observer