Table 8.
Effect of the inverse regression-based prediction and measurement error correction on Ki67 dichotomisation accuracy at various reference value cutoffs (n = 164)
| Method | Underestimated (%) | Overestimated (%) | Total misclassified (%) |
|---|---|---|---|
| Ki-67 cutoff >10% |
|
|
|
| Ki67-VE-median |
16/148 (11) |
2/16 (13) |
18 (11) |
| Ki67-DIA-2 |
0/148 (0) |
12/16 (75) |
12 (7) |
| Ki67-DIA-2 corrected |
0/148 (0) |
9/16 (56) |
9 (5) |
| Ki67-DIA-2 corrected <40* |
2/148 (1) |
6/16 (38) |
8 (5) |
| Ki-67 cutoff >15% |
|
|
|
| Ki67-VE-median |
22/136 (16) |
1/28 (4) |
23 (14) |
| Ki67-DIA-2 |
2/136 (1) |
13/28 (46) |
15 (9) |
| Ki67-DIA-2 corrected |
3/136 (2) |
11/28 (46) |
14 (9) |
| Ki67-DIA-2 corrected <40* |
5/136 (4) |
6/28 (21) |
11 (7) |
| Ki-67 cutoff >20% |
|
|
|
| Ki67-VE-median |
28/123 (23) |
1/41 (2) |
29 (18) |
| Ki67-DIA-2 |
2/123 (2) |
9/41 (22) |
11 (7) |
| Ki67-DIA-2 corrected |
2/123 (2) |
12/41 (29) |
14 (9) |
| Ki67-DIA-2 corrected <40* | 6/123 (5) | 6/41 (15) | 12 (7) |
*Ki67-DIA-2 < 40 - represents a regression model for Ki67-DIA-2 with only Ki67-Count less than 40% cases included in the analysis (n = 92). DIA, digital image analysis; VE, visual estimate.