Table 1.
Comparison of 1p/19q codeleted and non-1p/19q codeleted anaplastic oligodendrogliomas
| All patients* | Non-1p/19q codeleted patients | 1p/19q codeleted patients | P values | |
|---|---|---|---|---|
| N | 203 | 41 | 157 | |
| Age at diagnosis (mean) | 50.6 | 51.2 | 50.1 | NS |
| Sex | NS | |||
| Male (%) | 114 (56%) | 23 (56%) | 86 (55%) | |
| Female (%) | 89 (44%) | 18 (44%) | 71 (45%) | |
| Sex ratio M:F | 1:3 | 1:3 | 1:2 | |
| Preoperative KPS | NS | |||
| ≥80% (%) | 111 (83%) | 29 (85%) | 82 (83%) | |
| <80% (%) | 22 (17%) | 5 (15%) | 17 (17%) | |
| Extent of surgery | P = .05 | |||
| Biopsy (%) | 25 (15%) | 9 (24%) | 14 (11%) | |
| Surgery (%) | 141 (85%) | 29 (76%) | 111 (89%) | |
| Postoperative treatment | P < .0001 | |||
| Radiotherapy(%) | 77 (49%) | 3 (10%) | 74 (59%) | |
| Chemotherapy (%) | 14 (9%) | 3 (10%) | 11 (9%) | |
| Radiotherapy + PCV (%) | 17 (11%) | 2 (7%) | 14 (11%) | |
| Temoradiation + temozolomide (%) | 50 (31%) | 22 (73%) | 26 (21%) | |
| MVP (%) | 169 (83%) | 36 (88%) | 129 (82%) | NS |
| Necrosis (%) | 63 (31%) | 18 (44%) | 44 (28%) | P = .06 |
| Palisading (%) | 34 (17%) | 13 (32%) | 21 (13%) | P = .01 |
| Nonpalisading (%) | 50 (25%) | 13 (32%) | 36 (23%) | NS |
| Calcifications (%) | 87 (43%) | 14 (34%) | 71 (45%) | NS |
| Number of mitoses (mean) | 12 | 15.6 | 10.6 | NS |
| KI67 expression (mean) | 21 | 24 | 21 | NS |
| INA positive expression (%) | 152 (75%) | 9 (22.5%) | 139 (88.5%) | P < .0001 |
| TP53 positive expression (%) | 32 (16%) | 12 (29%) | 18 (12%) | P = .01 |
| EGFR positive expression (%) | 41 (20%) | 8 (19.5%) | 30 (19%) | NS |
| IDH R132H positive expression (%) | 153 (75%) | 12 (29%) | 138 (88%) | P < .0001 |
| IDH1/2 mutation status (%) (Expression and DNA sequencing) | 173 (85%) | 18 (44%) | 152 (97%) | P < .0001 |
| Amplifications (%) | 16 (8%) | 16 (41%) | 0 | P < .0001 |
| EGFR (%) | 5 (2.5%) | 5 (13%) | P = .0002 | |
| PDGFRA (%) | 4 (2%) | 4 (10%) | P = .001 | |
| CDKN2A homozygous deletion (%) | 11 (5.5%) | 10 (24%) | 1 | P < .0001 |
| Chr 1p partial loss (%) | 11 (6%) | 11 (29%) | 0 | NR |
| Chr 4 loss (%) | 48 (25%) | 1 (3%) | 47 (31%) | P = .0002 |
| Chr 7 gain (%) | 33 (17%) | 17 (45%) | 16 (10%) | P < .0001 |
| Chr 9p loss (%) | 53 (28%) | 12 (31%) | 41 (27%) | NS |
| Chr 9q loss (%) | 23 (12%) | 0 | 23 (15%) | P = .01 |
| Chr 10 loss (%) | 23 (12%) | 17 (44%) | 6 (4%) | P < .0001 |
| Chr 11q gain (%) | 24 (12.5%) | 0 | 24 (16%) | P = .01 |
| Chr 17p loss | 4 (4%) | 6 (16%) | 1 | P = .001 |
| Chr 19q loss (%)** | 166 (82%) | 9 (24%) | 100% | NR |
| Mean number of chr arm alteration | 5.1 | 7.1 | 4.7 | P = .003 |
*1p/19q codeletion status was unavailable in 5 of the 203 patients for technical reasons.
**15% of non-1p/19q codeleted anaplastic oligodendrogliomas displayed both partial 1p loss and 19q loss.
Abbreviations: chr, chromosome; F, female; KPS, Karnofsky performance status; M, male; MVP, microvascular proliferation; NR, not relevant; NS, not significant; PCV, procarbazine, lomustine, and vincristine.