Table 3.

Association between ovarian cancer risk factors and risk of ovarian cancer by ERβ-nuclear staining^a,b

		ERβ-nuclear (+)		ERβ-nuclear (–)
	Controls	Cases	OR (95% CI)	Cases	OR (95% CI)	p-hetero
Height
Per 5 cm	1,049	175	1.20 (1.05, 1.38)	70	1.06 (0.86, 1.30)	0.28
BMI
<25	481	92	1.00 (Ref)	34	1.00 (Ref)	0.52
25 – <30	329	42	0.65 (0.44, 0.96)	16	0.65 (0.35, 1.21)
≥30	184	24	0.69 (0.43, 1.13)	14	1.07 (0.56, 2.05)
per kg/m2	994	158	0.97 (0.93, 1.00)	64	1.01 (0.96, 1.06)	0.13
Family history of breast or ovarian cancer
No	896	144	1.00 (Ref)	59	1.00 (Ref)	0.66
Yes	154	31	1.29 (0.84, 1.98)	11	1.09 (0.56, 2.13)
Parity
Nulliparous	59	19	1.00 (Ref)	3	1.00 (Ref)	0.04
Parous	978	150	0.46 (0.26, 0.81)	67	1.51 (0.45, 5.04)
Nulliparous	59	19	1.00 (Ref)	3	1.00 (Ref)	0.13
1–2 children	400	76	0.56 (0.31, 1.01)	35	1.86 (0.55, 6.31)
3+ children	578	74	0.37 (0.20, 0.67)	32	1.16 (0.34, 4.03)
Per childc	1037	169	0.89 (0.80, 1.00)	70	0.95 (0.82, 1.12)	0.48
Per childd	978	150	0.94 (0.83, 1.06)	67	0.92 (0.77, 1.11)	0.84
Oral contraceptive use
Never	487	85	1.00 (Ref)	36	1.00 (Ref)	0.31
Ever	544	89	0.84 (0.59, 1.19)	29	0.61 (0.35, 1.06)
Never	487	85	1.00 (Ref)	36	1.00 (Ref)	0.60
<1 year	120	17	0.72 (0.40, 1.27)	6	0.61 (0.25, 1.51)
1–5 years	217	42	1.02 (0.66, 1.57)	11	0.58 (0.28, 1.22)
>5 years	207	30	0.73 (0.46, 1.18)	12	0.63 (0.31, 1.30)
Per yearc	1031	174	1.01 (0.99, 1.03)	65	1.00 (0.97, 1.03)	0.58
Per yeare	544	89	1.01 (0.99, 1.03)	29	1.01 (0.98, 1.04)	0.76
Breastfeedingd
Never	397	70	1.00 (Ref)	34	1.00 (Ref)	0.28
Ever	418	61	0.85 (0.58, 1.24)	19	0.59 (0.33, 1.07)
0–1 months	397	70	1.00 (Ref)	34	1.00 (Ref)	0.57
1–6 months	203	33	0.92 (0.58, 1.45)	8	0.50 (0.22, 1.11)
7–11 months	73	9	0.70 (0.33, 1.49)	3	0.54 (0.16, 1.82)
12+ months	142	19	0.83 (0.47, 1.44)	8	0.76 (0.34, 1.71)
Ovulatory yearsf
Quartile 1	224	21	1.00 (Ref)	7	1.00 (Ref)	0.99
Quartile 2	224	41	2.05 (1.11, 3.77)	15	2.03 (0.78, 5.27)
Quartile 3	241	36	1.78 (0.91, 3.48)	12	1.51 (0.54, 4.23)
Quartile 4	208	34	1.79 (0.88, 3.62)	13	1.71 (0.60, 4.87)
Per year	897	132	1.02 (0.98, 1.06)	47	1.02 (0.96, 1.08)	0.98
Tubal ligation
Never	837	152	1.00 (Ref)	63	1.00 (Ref)	0.57
Ever	213	23	0.57 (0.35, 0.91)	7	0.44 (0.20, 0.99)
Age at menarche
<13 years	512	85	1.00 (Ref)	34	1.00 (Ref)	0.96
≥13 years	438	90	1.04 (0.75, 1.43)	36	1.02 (0.63, 1.67)
Menopause status
Premenopausal	256	40	1.00 (Ref)	15	1.00 (Ref)	0.91
Postmenopausal	756	126	1.21 (0.69, 2.13)	53	1.14 (0.48, 2.73)
Age at menopauseg
<50 years	239	32	1.00 (Ref)	12	1.00 (Ref)	0.97
≥50 years	404	60	1.18 (0.74, 1.88)	23	1.16 (0.56, 2.39)
HT useg
Never	304	29	1.00 (Ref)	15	1.00 (Ref)	0.41
Ever	404	86	2.36 (1.50, 3.71)	33	1.72 (0.91, 3.24)
Estrogen-only HT useg,h
Never	495	65	1.00 (Ref)	22	1.00 (Ref)	0.16
Ever	171	43	2.06 (1.50, 3.71)	24	3.46 (1.85, 6.50)
Estrogen + Progesterone HT useg,i
Never	459	68	1.00 (Ref)	34	1.00 (Ref)	0.09
Ever	215	40	1.31 (0.85, 2.02)	10	0.67 (0.32, 1.39)

^a.Analyses were adjusted for cohort (NHS/NHSII), age at diagnosis (per year), duration of OC use (continuous in months), family history of breast/ovarian cancer (yes/no), menopausal and HT status (premenopausal/postmenopausal ever HT/postmenopausal never HT/missing HT), and number of pregnancies (continuous)

^b.Total N does not add up to 1,295 due to missingness in the exposure (height missing=1; BMI missing=79; parity missing=19; OC missing=25; breastfeeding missing=212; ovulatory years missing=219; age at menopause missing=165; menopause missing=49; HT use missing=64; E-only HT use missing=115; E+P HT use missing=109)

^c.Among all women

^d.Among parous women

^e.Among women who ever used oral contraceptives

^f.Ovulatory years were calculated as age at natural menopause (or age at diagnosis for premenopausal women) minus age at menarche with additional subtraction for OC duration and one year for each pregnancy

^g.Among postmenopausal women

^h.Additionally adjusted for estrogen plus progestin HT use (ever/never) and other HT use (ever/never)

^i.Additionally adjusted for estrogen-only HT use (ever/never) and other HT use (ever/never)