Table 3.

Clinicopathological characteristics of HER2-low Expression Evolution.

Characteristic	Total (n = 194)				TNBC(n = 33)				HR positive (n = 161)
	HER2-stable n = 146	HER2-loss n = 36	HER2-gain n = 12	P	HER2-stable n = 18	HER2-loss n = 11	HER2-gain n = 4	P	HER2-stable n = 128	HER2-loss n = 25	HER2-gain n = 8	P
Histology type				0.104				0.047				0.149
IBC-NST	121	30	7		17	7	2		104	23	5
Other	25	6	5		1	4	2		24	2	3
cT				0.278				0.016				0.734
T1-2	97	21	10		9	2	4		88	19	6
T3-4	49	15	2		9	9	0		40	6	2
cN				0.025				0.077				0.014
N0-1	82	17	2		14	4	2		68	13	0
N2-3	64	19	10		4	7	2		60	12	8
Clinical stage				0.201				0.472				0.030
II	63	15	2		5	2	2		58	13	0
III	83	21	10		13	9	2		70	12	8
HR				0.010				–				–
Positive	128	25	8		0	0	0		128	25	8
Negative	18	11	4		18	11	4		0	0	0
Ki-67				0.008				0.150				0.066
≤ 30 %	47	5	0		4	0	0		43	5	0
>30 %	99	31	12		14	11	4		85	20	8

IBC-NST, invasive breast cancer, no special type; HR, estrogen receptor.