Breast density change as a predictive surrogate for response to adjuvant endocrine therapy in hormone receptor positive breast cancer

Table 1 Patient demographics

Variable	Mean ± SD (range)	Number	%
Age, yr	49.0 ± 9.3 (24-77)
≤ 50		680	63.8
> 50		385	36.2
Duration of ET, yr	5.0 ± 1.0 (0.9-7.9)
ET regimen
Tamoxifen 5 yr		657	61.7
Tamoxifen 2-3 yr - > AI (total 5 yr) yr		41	3.8
Tamoxifen 5 yr - > AI		192	18
AI 5 yr			16.4
Tumor size (cm)	2.1 ± 1.4 (0.1-10.0)
≤ 2 cm		638	59.9
> 2 cm		427	40.1
Lymph node status
Negative		706	66.3
Positive		359	33.7
Histologic grade
Low/Intermediate		825	77.5
High		240	22.5
Progesterone receptor
Negative		477	44.8
Positive		588	55.2
HER2
Negative		976	91.6
Positive		88	8.3
Ki-67
< 10		895	84
≥ 10		169	15.9
Neoadjuvant chemotherapy
No		1017	95.5
Yes		48	4.5
Operation
Breast conserving surgery		667	62.6
Mastectomy		398	37.4
Adjuvant chemotherapy
No		247	23.2
Yes		818	76.8
Radiotherapy
No		408	38.3
Yes		657	61.7
Recurrence
Total		80	7.5
Locoregional		21	26.2
Contralateral breast		8	10
Distant metastasis		51	63.8

Clinicopathological factors of the 1065 patients. ET: endocrine therapy; AI: aromatase inhibitor; HER2: Human Epidermal Growth Factor Receptor 2.

ISSN: 1465-542X