Table 2.

Associations between morphological characteristics and tumour budding, single-cell invasion and nuclear diameter (STAS: spread through air spaces, NA: not applicable)

Parameters	Absence of tumour budding	Presence of tumour budding	p	Absence of single-cell invasion	Presence of single-cell invasion	p	Small nuclear diameter	Large nuclear diameter	p
	n			n			n
Histological subtype			<0.001*			0.325*			0.009*
Keratinising	29	83		56	56		67	45
Non-keratinising	39	52		51	40		70	21
Basaloid	10	7		10	7		13	4
Tumour budding			NA			<0.001			0.023
Absent	78			68	10		61	17
Present		142		49	93		89	53
Type of invasive border			<0.001			<0.001			0.073
Pushing margin	69	91		101	59		115	45
Infiltrative margin	9	51		16	44		35	25
Minimal cell nest size			<0.001*			<0.001*			0.035*
Single cell	10	93		0	103		64	39
Small	0	49		45	0		30	15
Intermediate	20	0		22	0		17	5
Large	48	0		50	0		39	11
Single-cell invasion			<0.001			NA			0.082
Absent	68	49		117			86	31
Present	10	93			103		64	39
Nuclear diameter			0.023			0.082			NA
Small	61	89		86	64		150
Large	17	53		31	39			70
Mitotic activity						0.879			0.063
Low	23	29	0.139	27	25		41	11
High	55	113		90	78		109	59
Pleural invasion			0.021*			0.097*			0.412*
PL0	74	120		107	87		134	60
PL1	2	0		0	5		0	3
PL2	1	9		6	1		8	1
PL3	1	13		4	10		8	6
Vascular invasion			0.006			0.05			0.267
Absent	72	107		102	77		126	53
Present	7	34		16	25		25	16
Lymphovascular invasion			<0.001			<0.001			0.560
Absent	53	51		72	32		74	30
Present	26	90		46	70		77	39
Perineural invasion			0.122			0.097			0.434
Absent	71	114		104	81		129	56
Present	8	27		14	21		22	13
STAS			0.865			0.891			0.484
Absent	63	100		92	81		120	53
Present	16	41		25	22		30	17

*Kruskal-Wallis tests, others chi-square tests

Bold values denote statistical significance at the p < 0.05 level