Table 2.

Proband enrollment and biospecimen collection, by race/ethnicity, age at diagnosis, stage, first-degree cancer family history, neighborhood socioeconomic status, education, and country of birth.

	Breast cancer cases eligible as probands n = 4,780						Enrolled probands n = 3,620 a
	Enrollment a				Biospecimen collection b		Biospecimen collection c
	n	%	OR d	95% CI	n	%	n	%	OR e	95% CI
Overall participation	3,620	76			3,244	68	3,244	90
Race/ethnicity f
Non-Hispanic whites	866	81	1.0		816	76	816	94	1.0
Hispanics	1,072	75	0.85	0.69-1.04	1,013	71	1,013	95	1.55	0.99-2.41
African Americans	831	76	0.88	0.71-1.10	762	69	762	92	0.83	0.56-1.25
Asian Americans	851	72	0.68	0.55-0.83	653	55	653	76	0.30	0.20-0.45
Chinese	387	74	0.80	0.62-1.04	279	54	279	72	0.23	0.15-0.36
Japanese	94	75	0.77	0.50-1.20	83	66	83	88	0.51	0.25-1.02
Filipinas	267	66	0.51	0.39-0.66	201	50	201	75	0.27	0.16-0.44
Others g	103	75	0.79	0.52-1.21	90	65	90	87	0.50	0.25-1.00
P value for differences by race/ethnicity h		<0.01	<0.01			<0.01		<0.01	<0.01
Age at diagnosis (years)
18-34	371	76	1.0		343	70	343	92	1.0
35-49	1,395	75	0.93	0.73-1.18	1,252	67	1,252	90	1.57	1.01-2.43
50-64	1,854	76	0.93	0.80-1.07	1,649	68	1,649	89	1.12	0.88-1.42
P value for differences by age h		0.55	0.56			0.40		0.13	0.12
Stage at diagnosis i
In situ	299	79	1.01	0.77-1.33	277	73	277	93	1.32	0.82-2.14
Localized	1,915	78	1.0		1,745	71	1,745	91	1.0
Regional	1,087	79	1.06	0.90-1.24	965	70	965	89	0.77	0.59-1.00
Distant	70	76	0.88	0.54-1.44	55	60	55	79	0.36	0.19-0.68
Missing	249	52	0.31	0.26-0.39	202	42			0.57	0.39-0.82
P value for differences by stage h		0.01	<0.01			0.01		<0.01	<0.01
Cancer family history j
Yes	1,388	78	1.06	0.91-1.23	1,269	71	1,269	91	1.10	0.85-1.42
No	2,232	75	1.0		1,975	66	1,975	88	1.0
P value for differences by family history h		0.01	0.46			<0.01		<0.01	0.45
Neighborhood socioeconomic status k
1 (low)	680	78	1.0		609	70	609	90	1.0
2	718	76	0.89	0.71-1.11	646	68	646	90	1.03	0.72-1.48
3	690	75	0.84	0.67-1.04	623	67	623	90	1.08	0.75-1.57
4	745	75	0.86	0.69-1.07	661	66	661	89	0.91	0.64-1.30
5 (high)	787	75	0.88	0.71-1.09	705	68	705	90	1.00	0.70-1.43
P value for differences by neighborhood SES h		0.45	0.57			0.58		0.90	0.92
Education l
Some high school or less							469	91	1.0
High school graduate							476	87	0.60	0.39-0.93
Some college or other m							1,129	92	1.20	0.79-1.82
College graduate							1,164	88	0.98	0.66-1.48
P value for differences by education h								<0.01	<0.01
Country of birth n
U.S.-born							2,128	93	1.0
Foreign-born							1,115	84	0.66	0.49-0.90
P value for differences by country of birth h								<0.01	0.01

Abbreviations: SES socioeconomic status, OR odds ratio, CI confidence interval

^aCompleted the family history and risk factor questionnaires.

^bCompleted the family history and risk factor questionnaires and provided a blood or mouthwash sample.

^cEnrolled probands who provided a blood or mouthwash sample.

^dOdds ratio of participation and 95% confidence interval, mutually adjusted for race/ethnicity, age at diagnosis, neighborhood SES.

^eOdds ratio of participation and 95% confidence interval, mutually adjusted for race/ethnicity, age at diagnosis, neighborhood SES, education, and country of birth. stage, cancer family history, and stage, cancer family history.

^fBased on self-report.

^gIncludes other Asian Americans, Pacific Islanders, Native Americans, and mixed race/ethnicity.

^hP value from chi square test; in multivariable models, P value from Wald test.

ⁱSEER summary stage.

^jFamily history of breast, ovarian or childhood cancer in first-degree relatives.

^kNeighborhood SES based on a composite measure of seven SES indicators from Census data at the level of block groups and categorized according to the quintile distribution of eligible breast cancer cases.

^lEducation was missing for 14 probands.

^mTechnical or vocational school.

ⁿCountry of birth was missing for 4 probands.