TABLE 1.
Assessment of Multiplex IHC and H&E Compared With GS
| Multiplex IHC (vs. GS) | H&E (vs. GS) | GS | |
|---|---|---|---|
| Total cores assessed | 6463 | 1589 | 8052 |
| Cores positive for cancer | 780 | 190 | 970 |
| Cores negative for cancer | 5683 | 1399 | 7082 |
| Prevalence of cancer (%) | 12.02 | 12.07 | 12.05 |
| Concordance [n (%)] | 6312 (97.66) | 1499 (94.34) | — |
| No. true-positive cores (A) | 772 | 179 | — |
| No. false-positive cores (B) | 8* | 11† | — |
| No. true-negative cores (C) | 5678 | 1386 | — |
| No. false-negative cores (D) | 5‡ | 13§ | — |
| Sensitivity (%) | 99.36 | 93.23 | — |
| Specificity (%) | 99.86 | 99.21 | — |
| Positive predictive value (%) | 98.98 | 94.21 | — |
| Negative predictive value (%) | 99.91 | 99.07 | — |
| False-positive rate for cores (%) | 0.14 | 0.78 | — |
| False-negative rate for cores (%) | 0.64 | 6.77 | — |
| Overestimation of cancer/core (%) | 3.11 | 17.33 | — |
| Underestimation of cancer/core (%) | 4.27 | 15.64 | — |
| Overestimation of Gleason grade/core (%) | 4.40 | 5.59 | — |
| Underestimation of Gleason grade/core (%) | 7.12 | 4.47 | — |
Eight false-positive cores on multiplex IHC comprising 7 cases. In 6 cases, the overall diagnosis was identical to the final GS diagnosis. In 1 case, the diagnosis (<5% Gleason grade 3+4) was different to the GS (atypical small acinar proliferation).
Eleven false-positive cores on H&E comprising 6 cases. In 5 cases, the overall diagnosis was identical to the final GS diagnosis (as other cores in the case contained cancer−true positives using H&E only). In 1 case, the overall diagnosis on H&E only (<5% Gleason grade 3+3) was different to the final GS diagnosis (negative for cancer).
Five false-negative cores on multiplex IHC comprising 5 cases. In all cases, the overall diagnosis was identical to the final GS diagnosis as there were other cores present that indicated a diagnosis of cancer (true positives using IHC only).
Thirteen false-negative cores on H&E comprising 12 cases. In 10 cases, the overall diagnosis was identical to the final GS diagnosis (as other cores in the case contained cancer−true positives using H&E only). In 2 cases, the diagnosis, if made using H&E only (negative for cancer) was different to the final GS diagnosis (<5% Gleason grade 3+4, 5% Gleason grade 3+3).
GS indicates gold standard; H&E, hematoxylin and eosin; IHC, immunohistochemistry.