Table 1.

Patient Demographics and Clinical Characteristics

Characteristic	All Biopsied Patients (n = 121)		Concordant Group* (n = 53)		Discordant Group* (n = 41)		P
	No.	%	No.	%	No.	%
Age, years
Median	59		58.5		59		.20
Range	29-83		35-83		36-72
Adjuvant treatment
Chemotherapy	63	52.1	20	36.4	21	51.2	.19
Endocrine therapy	90	75	28	50.9	17	41.5	.50
Trastuzumab	5	4.1	2	3.6	2	4.9	.85
Advanced disease status
Newly diagnosed metastatic	56	46.3	11	20.0	7	17.1
1 prior line of treatment in metastatic setting	21	17.4	15	27.3	10	24.4	.65
≥2 lines of treatment in metastatic setting	44	36.4	29	52.7	24	58.5
Duration of metastatic disease, months
Median	35		18		24		.35
Range	0-274		0.5-79		0.5-108
Palliative treatment
Median lines of endocrine therapy	2		1		1		.10
Median lines of chemotherapy	1		1		0		.26

^*Includes only those patients with availability of matched primary and metastatic tissue.