Table II.
EGFR immunohistochemistry scores interobserver agreement.
| Score | Overall | Pathologist A | Pathologist B | Pathologist C |
|---|---|---|---|---|
| EGFR score | ||||
| Mean (± SD) | 125.41 (96.36) | 111 (102.08) | 126.65 (103.05) | 128.53 (104.037) |
| Contingency coefficient | 0.982 | 0.980 | 0.988 | |
| EGFR score 1 | ||||
| <1 | 14.1 (12/85) | 31.8 (27/85) | 30.6 (26/85) | 14.1 (12/85) |
| ≥1 | 85.9 (73/85) | 68.2 (27/85) | 69.4 (59/85) | 85.9 (73/85) |
| Spearman's rho | 0.487 | 0.495 | 0.604 | |
| κ measurement agreement | 0.101 | 0.102 | 0.123 | |
| EGFR score 100 | ||||
| <100 | 45.9 (39/85) | 47.1 (40/85) | 41.2 (35/85) | 42.4 (36/85) |
| ≥100 | 54.1 (46/85) | 52.9 (45/85) | 58.8 (50/85) | 57.6 (49/85) |
| Spearman's rho | 0.834 | 0.857 | 0.734 | |
| κ measurement agreement | 0.201 | 0.193 | 0.082 | |
| EGFR score 200 | ||||
| <200 | 71.8 (61/85) | 74.1 (63/85) | 62.4 (53/85) | 58.8 (50/85) |
| ≥200 | 28.2 (24/85) | 25.9 (22/85) | 37.6 (32/85) | 41.2 (35/85) |
| Spearman's rho | 0.773 | 0.71 | 0.675 | |
| κ measurement agreement | 0.116 | 0.111 | 0.044 | |
| EGFR score 250–300 | ||||
| <250 | 87.1 (74/85) | 84.7 (72/85) | 88.2 (75/85) | 82.4 (70/85) |
| 250–300 | 12.9 (11/85) | 15.3 (13/85) | 11.8 (10/85) | 17.6 (15/85) |
| Spearman's rho | 0.635 | 0.545 | 0.541 | |
| κ measurement agreement | 0.057 | 0.056 | 0.021 |
EGFR, epidermal growth factor receptor; SD, standard deviation.