Table 1. Clinicopathological information of the enrolled patients.

Factors	All patients (n = 38)		Without lymph node metastasis (n = 27)		With lymph node metastasis (n = 11)		p value
	number	%	number	%	number	%
Age (mean)	59.6		63 ± 11		58 ± 14		0.15
T
is-1	21	55	17	63	4	36	0.13
2–4	17	45	10	37	7	64
Histology
Invasive ductal carcinoma	27	71	17	63	10	91	0.055
Papillo-tubular	6		6		0
Solid-tubular	8		5		3
Scirrhous	8		4		4
Other	5		2		3
DCIS	7	18	7	26	0	0
Special types	4	11	3	11	1	9
HER2 receptor
Positive	6	20	2	11	4	36	0.09
Negative	24	80	17	89	7	64
Lymph node metastasis
Absent	27	71	7	41	1	10	0.09
Present	11	29	10	59	9	90
Lymphatic invasion
0, 1	27	90	18	95	9	82	0.26
2, 3	3	10	1	5	2	18
Venous invasion
0, 1	30	100	19	100	11	100
2, 3	0	0	0	0	0	0
Operation
Mastectomy + ALND	17	45
Mastectomy + SLNB	3	8
BCS*** + ALND	1	3
BCS + SLNB	17	45

*T factor was assessed according to the TNM Classification of Malignant Tumors, 7^th edition²⁰.

**Not available for one case, and no examination was performed for seven DCIS cases.

^***Breast conserving surgery.