Table 1: Characteristics of patients without CNS metastases at the time of starting trastuzumab for metastatic breast cancer.

CharacteristicAll Patients ( 𝑁 = 5 6 2 )

Age at start of trastuzumab (years), Median (IQR)75 (71–79)

Months from diagnosis to trastuzumab, Median (IQR)2 (1–6)

Age category, 𝑛 (%)66–6994 (17)
70–74181 (32)
75–79148 (26)
≥80139 (25)

Race/ethnicity, 𝑛 (%)White455 (81)
Black62 (11)
Hispanic23 (4)
Other22 (4)

Year trastuzumab therapy started, 𝑛 (%)200019 (3)
200147 (8)
200268 (12)
200389 (16)
2004119 (21)
2005136 (24)
200684 (15)

Comorbidity score at start of trastuzumab, 𝑛 (%)0495 (88)
145 (8)
≥222 (4)

Stage at initial diagnosis, 𝑛 (%)Recurrent Stage 0–III336 (60)
Incident Stage IV226 (40)

ER/PR Status, 𝑛 (%)Both ER and PR positive143 (25)
Either ER or PR positive91 (16)
Both ER and PR negative251 (45)
Unknown77 (14)

Metastases at start of trastuzumab, 𝑛 (%)Bone269 (48)
Liver172 (31)
Lung/Chest184 (33)
All Other162 (29)

Note: IQR: interquartile range, ER: estrogen receptor, PR: progesterone receptor.