Table 1. Clinicopathological characteristics of the 23 patients.

Sample ID	Primary Tumor					Systemic treatment between primary tumor and profiled metastasis	Metastatic location	Delay between primary tumor and metastasis (months)	N° of metastatic relapse or progression
	Age at diagnosis	Pathological type	Pathological grade	ER status*	ERBB2 status*
1	63	Mixed	2	Positive	Negative	Yes (chemoT, hormonoT)	Lymph nodes	26	1
2	52	Ductal	2	Positive	Negative	Yes (chemoT, hormonoT)	Skin	110	2
4	33	Ductal	3	Positive	Negative	Yes (chemoT, hormonoT)	Liver	35	1
5	56	Ductal	3	Negative	Negative	Yes (chemoT)	Lymph nodes	25	1
6	41	Mixed	2	Positive	Positive	Yes (chemoT, hormonoT)	Skin	39	1
7	43	Medullary	3	Negative	Negative	Yes (chemoT)	Muscle	27	1
8	61	Ductal	1	Positive		Yes (chemoT, hormonoT)	Liver	11	1
9	72	Lobular	2	Positive	Negative	Yes (chemoT, hormonoT)	Uterus	61	1
10	41	Ductal	1	Positive	Negative	Yes (chemoT, hormonoT)	Ovary	32	3
11	34	Ductal		Positive	Negative	Yes (chemoT)	Ovary	5	1
12	50	Ductal		Positive		No	Lymph nodes	81	1
13	51	Ductal	3	Negative	Positive	Yes (hormonoT)	Lung	36	1
14	34	Ductal	2	Negative		Yes (chemoT, hormonoT)	Bladder	23	1
15	35	Ductal	1			No	Lymph nodes	88	1
16	38	Ductal	3	Positive	Positive	Yes (chemoT)	Skin	12	1
17	70	Lobular	1	Negative	Negative	Yes (chemoT)	Skin	42	1
18	62	Ductal	3	Negative	Positive	Yes (chemoT, trastuzumab, lapatinib, BKM120, T-DM1)	Skin	25	3
20	60	Ductal	2	Positive	Positive	Yes (chemoT, hormonoT, trastuzumab, lapatinib, T-DM1)	Peritoneum	149	4
21	37	Ductal		Positive	Negative	Yes (chemoT, hormonoT)	Lymph nodes	73	6
22	33	Ductal	3	Positive	Negative	Yes (chemoT, hormonoT, trastuzumab)	Liver	52	4
23	38	Metaplastic	3	Negative	Negative	Yes (chemoT)	Liver	0	1
24	34	Ductal		Positive	Negative	Yes (chemoT, hormonoT)	Liver	63	4
26	38	Ductal	3	Positive	Positive	Yes (chemoT, hormonoT, trastuzumab)	Ovary	78	1

^*IHC status: ER (10% positivity cut-off) and ERBB2 (0–3 + score, DAKO HercepTest, with > 1 + defined as positive).