Table 1.
Study demographics
| Features | Cases N = 71 (%) | EGFR-Amplified N = 20 (%) | No EGFR Amplification N = 51 (%) | P-value |
|---|---|---|---|---|
| Tumor type | 0.000197* | |||
| Anaplastic astrocytoma, IDH-wildtype | 29 (40.8%) | 19 (95%) | 10 (19.6%) | 0.0002** |
| Anaplastic astrocytoma, IDH-mutant | 26 (36.6%) | 1 (5.0%) | 25 (49.0%) | |
| Anaplastic oligodendroglioma, IDH-mutant and 1p/19q codeleted | 3 (4.2%) | 0 (0%) | 3 (5.9%) | |
| Diffuse astrocytoma, IDH-wildtype | 5 (7.0%) | 0 (0%) | 5 (9.8%) | |
| Diffuse astrocytoma, IDH-mutant | 3 (4.2%) | 0 (0%) | 3 (5.9%) | |
| Oligodendroglioma IDH-mutant and 1p/19q codeleted | 5 (7.0%) | 0 (0%) | 5 (9.8%) | |
| WHO grade | ||||
| III | 58 (82%) | 20 (100%) | 38 (75%) | 0.0141* |
| II | 13 (12%) | 0 (0%) | 13 (25%) | |
| Median age in years | 46 | 61.5 | 41 | |
| Number of patients ≤55 | 53 (75%) | 7 (35%) | 46 (90%) | <0.00001* |
| Number of patients >55 | 18 (25%) | 13 (65%) | 5 (10%) | |
| MRI characteristics M | ||||
| Contrast enhancing | 37 (52%) | 14 (70%) | 23 (45%) | 0.070 |
| No enhancement | 34 (48%) | 6 (30%) | 28 (55%) | |
| MRI characteristics (IDH-wildtype) | (N = 34) | (N = 19) | (N = 15) | |
| Contrast enhancing | 24 (70.6%) | 16 (84.2%) | 8 (53.3%) | 0.068 |
| No enhancement | 10 (29.4%) | 3 (15.8%) | 7 (46.7%) | |
| MRI characteristics (WHO grade III) | (N = 58) | (N = 20) | (N = 38) | |
| Contrast enhancing | 45 (77.6%) | 17 (85%) | 28 (73.7%) | 0.509 |
| No enhancement | 13 (22.4%) | 3 (15%) | 10 (39.5%) | |
| Procedure type | (N = 20) | (N = 51) | ||
| Biopsy | 22 (31%) | 11 (55%) | 11 (22%) | 0.009 |
| Resection | 49 (69%) | 9 (45%) | 40 (78%) | |
| Procedure type (IDH-wildtype) | (N = 34) | (N = 19) | (N = 15) | |
| Biopsy | 16 (47%) | 10 (53%) | 6 (40%) | 0.51 |
| Resection | 18 (53%) | 9 (47%) | 9 (60%) |
* P-values derived from Fisher’s exact test (WHO grade, number of patients at age of diagnosis) and chi-square analysis (tumor type). ** Results from Fischer’s exact test comparing EGFR-amplified vs non-amplified anaplastic astrocytomas, IDH-wildtype vs all other groups combined. Significant difference in tumor type is caused by the high number of EGFR-amplified tumors in this subgroup. Msee also Supplementary Table 2.