Table 2.
Incidence of biomarkers
| Biomarker | Overall | Grade III | Grade IV | p |
|---|---|---|---|---|
| n | 181 | 56 | 125 | – |
| MGMT (n tested) | 94 | 31 | 63 | 0.037 |
| Methylated, n (%) | 36 (38) | 17 (55) | 19 (30) | – |
| Non-methylated, n (%) | 58 (62) | 14 (45) | 44 (70) | – |
| 1p19q co-deletion (n tested) | 92 | 39 | 53 | < 0.01 |
| Present, n (%) | 17 (18) | 16 (41) | 1 (2) | – |
| Absent, n (%) | 75 (82) | 23 (59) | 52 (98) | – |
| IDH1 mutation (n tested) | 102 | 23 | 79 | 0.074 |
| Present, n (%) | 20 (20) | 8 (35) | 12 (15) | – |
| Absent, n (%) | 82 (80) | 15 (65) | 67 (85) | – |
| ATRX (n tested) | 32 | 7 | 25 | 0.440 |
| ATRX loss, n (%) | 2 (6) | 0 | 2 (8) | – |
| ATRX intact, n (%) | 30 (94) | 7 (100) | 23 (92) | – |
MGMT O6-methylguanine-DNA-transferase; IDH1 isocitrate dehydrogenase 1; ATRX alpha-thalassemia/mental retardation syndrome X-linked. P-values were calculated from two-sided Chi-square statistics with Yates correction to compare the presence or absence of the specific biomarker in grade III versus grade IV gliomas
Figures in boldface represent p values of less than 0.05