Table 1. Participant characteristics.

	ALL (n=54) N (%)	HR (n=35) N (%)	PR (n=19) N (%)
Age
11-13 YO	13 (24)	9 (26)	4 (21)
14-16 YO	26 (48)	16 (46)	10 (52)
17-19 YO	15 (28)	10 (29)	5 (26)
Mother’s history
Mother has history of breast cancer	11 (20)	11 (31)	0
Mother has a BRCA1/2 mutation	6 (11)	6 (17)	0
High-risk subgroups
BRCA1/2+ mother with breast cancer		4 (11)
BRCA1/2+ mother without breast cancer		2 ( 6)
Mother* with breast cancer AND family history of breast cancer		4 (11)
Mother* with breast cancer only (no family history)		2 ( 6)
2 or more second-degree relatives** with breast cancer		6 (17)
1 second-degree relative** with breast cancer		17 (49)
Site
Fox Chase Cancer Center	40 (74)	31 (86)	9 (50)
Community practice	14 (26)	5 (14)	9 (50)
Number unique families	53	35	18

^*BRCA1/2 negative or unknown (i.e. not tested for BRCA1/2)

^**grandparent or aunt/uncle