Table 1.

Patient demographics and clinical characteristics before propensity score matching.

Characteristics	IMPC (n = 327) n	%	IDC (n = 4979) n	%	p value
Age, years					0.623
Mean	52.4		52.1
SDa	11.0		10.7
Tumour size, cm					0.121
T ≤ 2	131	40.1	2250	45.1
2 < T ≤ 5	182	55.7	2578	51.8
T ≥ 5	14	4.3	151	3.0
Node status					0.000
0	101	30.9	2640	53.0
1–3	85	26.0	1273	25.6
4–9	72	22.0	623	12.5
≥ 10	69	21.1	443	8.9
TNM stage					0.000
I	58	17.7	1379	27.7
II	126	38.5	2500	50.2
III	143	43.7	1100	22.1
LVI b					0.000
yes	233	71.3	1779	35.7
no	73	22.3	2097	42.1
unknown	21	6.4	1103	22.2
Hormone status
ERc positive	276	84.4	3743	75.2	0.000
PRd positive	261	79.8	3546	71.2	0.001
HER2e positive	108	33.0	1197	24.0	0.001
Surgery					0.292
MRMf	251	76.8	3836	77.0
BCSg	32	9.8	599	12.0
Mastectomy	28	8.6	315	6.4
Others	16	4.9	229	4.6

SD^a: standard deviation.

LVI^b: lymphovascular invasion.

ER^c: oestrogen receptor.

PR^d: progestin receptor.

HER2^e: epidermal growth factor receptor 2.

MRM^f: modified radical mastectomy.

BCS^g: breast conserving surgery.