Table 3.

Mean percentage mammographic density (MD) according to breast cancer susceptibility loci, Nurses' Health Study controls (1989–1998)

		Premenopausal (n = 217)			Postmenopausal (n = 904)
		N	Mean %MDa	Mean %MDb	N	Mean %MDa	Mean %MDc
rs2981582	G/G	73	37.4	37.9	332	24.4	24.2
	G/A	112	40.5	40.7	407	23.9	23.6
	A/A	28	41.7	38.4	131	23.7	25.3
p value d			0.27	0.62		0.34	0.82
rs12443621	A/A	51	36.0	36.2	236	22.9	23.4
	A/G	104	38.9	39.1	442	24.5	24.2
	G/G	54	43.7	42.5	202	23.5	23.8
p value d			0.05	0.06		0.70	0.72
rs13281615	A/A	70	39.7	38.2	290	25.2	25.0
	A/G	94	36.0	38.2	445	23.7	23.9
	G/G	47	45.8	43.1	144	22.9	22.8
p value d			0.45	0.52		0.36	0.32
rs3817198	A/A	80	33.9	33.5	396	24.2	24.0
	A/G	106	42.6	42.3	368	24.4	24.6
	G/G	20	39.5	41.0	93	22.7	22.8
p value d			0.04	0.01		0.39	0.56
rs889312	T/T	107	41.1	41.3	499	25.6	25.4
	T/G	89	38.5	38.2	321	21.5	22.1
	G/G	14	38.8	37.2	58	26.8	25.3
p value d			0.40	0.21		0.17	0.14
rs4666451	G/G	74	40.7	41.6	314	24.0	24.5
	A/G	96	40.6	39.5	418	24.2	23.8
	A/A	36	33.0	33.6	144	24.3	24.3
p value d			0.13	0.06		0.90	0.40
rs2107425	G/G	105	41.7	40.7	449	24.3	24.6
	G/A	87	36.8	37.2	337	23.4	23.3
	A/A	18	37.5	39.6	85	24.6	23.6
p value d			0.11	0.29		0.79	0.37
rs981782	A/A	64	37.7	37.5	258	25.5	24.6
	A/C	100	39.4	39.2	429	23.7	24.1
	C/C	47	42.3	42.5	175	23.2	23.4
p value d			0.39	0.27		0.08	0.22
rs8051542	G/G	63	41.0	40.5	234	23.2	23.4
	G/A	73	40.0	40.1	296	22.3	22.3
	A/A	32	37.9	37.8	137	27.6	27.3
p value d			0.58	0.65		0.36	0.43
rs30099	C/C	175	38.8	38.8	723	24.4	24.5
	C/T	34	40.5	39.9	151	22.6	22.4
	T/T	0			8	26.0	21.8
p value d			0.45	0.51		0.49	0.16
rs3803662	G/G	107	37.0	36.9	458	23.9	24.1
	G/A	77	43.9	42.7	344	24.0	23.4
	A/A	20	32.7	36.1	69	26.5	28.0
p value d			0.55	0.34		0.64	0.50

^aAge adjusted.

^bMultivariate adjusted for the following: age (continuous), body mass index (BMI) (continuous), alcohol consumption (none, <5 g/day, 5 to 14.9 g/day, 15+ g/day), age at first birth/parity (nulliparous, age at first birth <25, age at first birth 25 to 29, age at first birth >30), history of benign breast disease (yes/no), family history of breast cancer (yes/no).

^cMultivariate adjusted for the following: age, BMI, alcohol consumption, age at first birth/parity, history of benign breast disease, family history of breast cancer, postmenopausal hormone use (never user, current user, past user).

^dp value based on genotype coded as ordinal variable regressed on square root transformed MD.