Table 2.

Clinico‐patho‐biological characteristics of NIP^high and NIP^low subgroups of oligodendrogliomas.

	NIPhigh	NIPlow
n	34	52
Age (y)	48.7 (11.1 n = 34)	44.9 (11.0 n = 52)	P = 0.121	NS, t test
Male	20	31	P = 0.941	NS, chi 2
Female	14	21
Frontal lobe involved	28	43	P = 0.811	NS, chi 2
Frontal lobe not involved	6	8
OD3	32	45	P = 0.470	NS, Fisher
OA3	2	7
Mitoses per 10 high power fields	11.3 (7.7 n = 30)	9.5 (7.0 n = 47)	P = 0.210	NS, Mann–Whitney
Microvasc. proliferation	32	38	P = 0.0142	NS, chi 2
No microvasc. proliferation	2	14
Necrosis	14	6	P = 0.0034*	S, chi 2
No necrosis	20	46
INA IHC +	33	46	P = 0.236	NS, Fisher exact test
INA IHC −	1	6
IDH mutant	30	51	(by definition)
IDH wt	1	1
CIC mutated CIC wt	14 7	15 16	P = 0.244	NS, chi 2 test
1p/19q co‐del	34	52	(by definition)
Non 1p/19q co‐del.	0	0
9p loss	9	14	P = 0.963	NS, chi 2 test
9p retained	25	38
10q loss	5	4	P = 0.146	NS, Fisher test
10q retained	26	51

Cases of training and validation series were gathered. Standard deviation is indicated between brackets. Number of cases is precised between brackets. The threshold of significance P < 0.05 was adjusted for multiple comparison by Bonferroni method. The adjusted threshold is P < 0.0045. Abbreviations: co‐del., co‐deletion; IHC, immunohistochemistry; microvasc., microvascular; NS, non‐significant; OA3, anaplastic oligo‐astrocytoma; OD3, anaplastic oligodendroglioma; S, significant; wt, wildtype, y: years.