Table 2.

Baseline characteristics of participating girls, by breast cancer family history, LEGACY Girls Study, 2011 – 2015

	Breast cancer in 1st degree relatives (N=220)		Breast cancer in 2nd degree relatives only (N=313)		No breast cancer in 1st or 2nd degree relatives (N=507)
	N	% a	N	% a	N	% a
Age at baseline (years)
5	2	1	5	2	5	1
6	20	9	34	11	47	9
7	17	8	40	13	58	11
8	22	10	37	12	72	14
9	29	13	47	15	75	15
10	28	13	42	13	74	15
11	27	12	30	10	69	14
12	31	14	34	11	60	12
13	29	13	35	11	37	7
14	5	2	5	2	5	1
15	8	4	4	1	4	1
16	2	<1	0	0	1	<1
Race/ethnicity
Non-Hispanic White	124	56	232	74	290	57
Hispanic White	45	20	40	13	83	16
Hispanic Black	13	6	2	1	10	2
African American or Black	13	6	16	5	49	10
Asian American or Pacific Islander	22	10	17	5	57	11
Mixed race/ethnicity	3	1	6	2	18	4
Education, mother or female guardian
High school graduate or less	23	11	33	11	57	11
Some college or university	35	17	47	15	89	18
Bachelor’s degree	83	40	106	35	188	38
Graduate degree	64	31	121	39	168	34
Not reported	15		6		5
Education, father or male guardian
High school graduate or less	39	19	53	18	95	24
Some college or university	32	15	46	16	74	19
Bachelor’s degree	72	34	96	33	128	32
Graduate degree	66	32	98	33	174	44
Not reported	11		20		36
Annual family Income
< $50,000	30	18	37	15	74	18
$50,000 – $74,999	19	11	21	8	50	12
$75,000 – $99,999	19	11	30	12	71	17
≥ $100,000 or more	103	60	163	65	235	55
Not reported	49		62		77

^aPercentages may not add up to 100 because of rounding. Missing data were not included in percentages.