Airborne metals and polycyclic aromatic hydrocarbons in relation to mammographic breast density

Breast Cancer Research

Table 1 Study participant characteristics by breast density (Breast Cancer Surveillance Consortium, 2011)

	Non-dense (N = 122,474; 55%)		Dense (N = 100,107; 45%)
	N	Row %	N	Row %
Age
≤ 45	11,198	35	21,145	65
46–50	11,716	40	17,752	60
51–55	16,034	51	15,371	49
56–60	22,305	59	15,606	41
61–65	21,832	64	12,540	36
66–69	15,864	67	7794	33
≥ 70	23,525	70	9899	30
Race
White	87,482	57	67,257	43
Black	13,720	62	8365	38
Asian, native Hawaiian or Pacific Islander	9846	37	16,612	63
Other	2847	56	2256	44
Hispanic	8579	60	5617	40
Body mass index
< 18.5	535	21	2042	79
18.5–24.9 kg/m²	23,987	38	39,821	62
25–29.9 kg/m²	24,678	62	15,195	38
≥ 30 kg/m²	27,607	79	7383	21
Missing	45,667	56	35,666	44
Ever given birth
No	23,636	48	25,165	52
Yes	98,838	57	74,942	43
Hormone therapy use
No	106,627	55	88,228	45
Yes	5873	51	5614	49
Missing	9974	61	6265	39
Menopausal status
Premenopausal	26,167	38	42,779	62
Postmenopausal	96,307	63	57,328	37
Zip code level median income
< $50,000	40,119	62	24,347	38
$50,000–$99,999	74,132	53	65,067	47
≥ $100,000	8223	43	10,693	57
Zip code level college education
Quartile 1	27,836	61	17,815	39
Quartile 2	33,424	58	24,535	42
Quartile 3	27,621	54	23,729	46
Quartile 4	33,593	50	34,028	50
BI-RADS
1	28,617	100	0	0
2	93,857	100	0	0
3	0	0	80,462	100
4	0	0	19,645	100

ISSN: 1465-542X