Table 1.

Patient clinicopathological characteristics at baseline

Characteristics	Cases (%)
ECOG
0	21 (52.5)
1	19 (47.5)
Age at diagnosis
≤ 35 years	7 (17.5)
> 35 years	33 (82.5)
Location
Left	27 (67.5)
Right	13 (32.5)
HER2 status
IHC 3+	32 (80.0)
IHC 2+ and FISH+	8 (20.0)
Hormone-receptor status
ER and/or PR positive	21 (52.5)
E R and PR negative	19 (47.5)
Previous anti-HER2 antibody treatment in metastatic setting
Yes	37 (92.5)
No	3 (7.5)
Previous anti-HER2 TKI treatment
Yes	21 (52.5)
No	19 (47.5)
Brain metastases
Yes	15 (37.5)
No	25 (62.5)
Liver or/and lung metastases
Yes	27 (67.5)
No	13 (32.5)
Number of previous treatment lines
≤ 2	27 (67.5)
> 2	13 (32.5)
Combined chemotherapeutic drug
Vinorelbine	25 (62.5)
Capecitabine	6 (15.0)
Nab-paclitaxel	5 (12.5)
Gemcitabine	4 (10.0)

ECOG Eastern Cooperative Oncology Group, HER2 human epidermal growth factor receptor 2, IHC immunohistochemistry, ER estrogen receptor, PR progesterone receptor