Table 4 Predictive value of each alternative technique compared with FISH expressed as HER2 copy number (cutoff set at 6 HER2 copies) in the overall population (n=840) and in the IHC 2+ subpopulation
Techniques | Population | Concordance (95%CI) | Sensitivity (95%CI) | Specificity (95%CI) | Positive predictive value (95%CI) | Negative predictive value (95%CI) |
|---|---|---|---|---|---|---|
IHC | All (N=840) | 95% [94-97] | 89% [84-92] | 98% [97-99] | 95% [92-98] | 95% [93-97] |
SISH | All (N=587) | 98% [96-99] | 95% [91-98] | 99% [98-100] | 98% [94-99] | 98% [96-99] |
IHC 2+ (N=60) | 90% [81-96] | 72% [47-90] | 96% [87-100] | 87% [60-98] | 91% [81-97] | |
CISH | All (N=204) | 75% [69-81] | 99% [92-100] | 64% [56-72] | 57% [48-67] | 99% [94-100] |
IHC 2+ (N=27) | 62% [42-79] | 100% [40-100] | 56% [35-76] | 27% [8-55] | 100% [77-100] | |
qPCR | All (N=773) | 93% [91-94] | 80% [75-85] | 98% [96-99] | 94% [90-97] | 92% [90-94] |
IHC 2+ (N=86) | 86% [78-92] | 45% [24-68] | 97% [91-100] | 83% [52-98] | 86% [77-93] |