Table 1.

Association of LVI with clinical and pathological characteristics

	Lymphovascular invasion status
	Negative		Positive		χ2
	n	%	n	%	P
All patients	13 117	75.7	4205	24.3
Age, years					<0.0001
≤40	673	57.6	495	42.38
40.1-50	2724	70.8	1123	29.19
50.1-74.9	8621	79.0	2295	21.02
≥75	1094	79.0	291	21.01
T size, mm					<0.0001
≤5	1016	94.3	61	5.66
5.1-10	4105	89.0	505	10.95
10.1-19.9	4909	75.8	1569	24.22
20-50	3087	59.9	2070	40.14
T histology					<0.0001
Ductal	10 049	72.8	3757	27.21
Lobular	1896	88.6	244	11.40
Mixed	229	73.4	83	26.60
Others	943	88.6	121	11.37
Grade					<0.0001
1	5317	88.6	681	11.35
2	5893	73.8	2091	26.19
3	1907	57.1	1433	42.90
pN status					<0.0001
pN0	9785	85.3	1686	14.70
pN0 (i+)	376	66.1	193	33.92
pN1mi	994	70.5	415	29.45
pN1 macro	1962	50.7	1911	49.34
Breast surgery					<0.0001
Conservative	11 138	77.8	3171	22.16
Mastectomy	1710	64.1	958	35.91
Unknown	269	78.0	76	22.03
Axillary surgery					<0.0001
SLNB	7888	87.8	1092	12.16
SLNB + ALND	3046	67.4	1476	32.64
ALND	2181	57.1	1637	42.88
Periods					<0.0001
<2005	6346	71.7	2499	28.25
≥2005	6771	79.9	1705	20.12
T location					<0.0001
Outer/equatorial	6282	73.7	2241	26.29
Inner	2906	74.7	982	25.26
Unknown	3929	80.0	982	20.00
Endocrine therapy					<0.0001
No	3082	72.5	1168	27.48
Yes	10 029	76.8	3034	23.23
Chemotherapy					<0.0001
No	8917	86.2	1427	13.80
Yes	4200	60.2	2778	39.81
RNI					<0.0001
No	7285	84.2	1367	15.80
Yes	3379	61.1	2153	38.92
Postmastectomy Radiotherapy					<0.0001
No	699	83.7	136	16.29
Yes	1009	55.1	821	44.86
Subtypes					<0.0001
Luminal A	7127	84.0	1362	16.04
Luminal B HER2− G3	611	56.4	473	43.63
Luminal B HER2+	448	66.7	224	33.33
HER2	231	64.2	129	35.83
Triple negative	737	74.4	254	25.63

ALND, axillary lymph node dissection; HER2, human epidermal growth factor receptor 2; LVI, lymphovascular invasion; RNI, regional node irradiation; SLNB, sentinel lymph node biopsy; T, tumor.