Pre-diagnosis oophorectomy, estrogen therapy and mortality in a cohort of women diagnosed with breast cancer

Breast Cancer Research

Table 1 Participant characteristics according to gynecologic surgery history prior to breast cancer diagnosis, Collaborative Breast Cancer Studies

	TAHBSO^a(N = 1,778)		Intact uterus and ovaries (N = 6,913)		P-value^b
Age at diagnosis, mean (SD)	63.5	6.9	63.2	6.8	0.08
Study enrollment years, %
1992-1995	876	49.3	3,177	46.0	0.01
1997-2001	527	29.6	2,071	30.0
2001-2004	172	9.7	690	10.0
2004-2007	203	11.4	975	14.1
State, %
WI	1,205	67.8	4,787	69.2	0.3
MA	433	24.4	1,568	22.7
NH	140	7.9	558	8.1
Smoking status at diagnosis, %
Never	955	53.7	3,237	46.8	<0.001
Former	564	31.7	2,376	34.4
Current	256	14.4	1,258	18.2
Missing	3	0.2	42	0.6
Education, %
High school diploma or less	1,070	60.2	3,924	56.8	0.04
Some college	383	21.5	1,538	22.2
College degree or higher	320	18.0	1,424	20.6
Parity, mean (SD)^c	3.1	1.6	3.1	1.6	0.5
Body mass index, %
Underweight (< 18.5 kg/m2)	24	1.3	102	1.5	0.002
Normal (18.5-24.9 kg/m2)	641	36.1	2,813	40.7
Overweight (25-29.9 kg/m2)	626	35.2	2,276	32.9
Obese (≥ 30 kg/m2)	450	25.3	1,542	22.3
Missing	37	2.1	180	2.6
Family history of breast cancer, %
Yes	418	23.5	1,445	20.9	0.04
Missing	27	1.5	127	1.8
Postmenopausal hormone therapy, %
None	539	30.3	4,541	65.7	<0.001
Estrogen only	1,033	58.1	399	5.8
Estrogen plus progestin only	52	2.9	1,561	22.6
Multiple/other formulations	129	7.3	336	4.9
Stage, %
Local	1,183	66.5	4,421	64.0	0.04
Regional	423	23.8	1,797	26.0
Distant	23	1.3	140	2.0
Unknown	149	8.4	555	8.0
Histology, %
Ductal	1,407	79.1	5,429	78.5	0.01
Lobular/non-ductal	122	6.9	615	8.9	0.01
Other	244	13.7	847	12.3

^aTAHBSO, total abdominal hysterectomy and bilateral salpingo-oophorectomy; ^bP value for t tests of continuous variables and chi-square tests of categorical variables; ^camong parous women only (N = 1,541 (86.7%) who reported TAHBSO; N = 6,016 (87.0%) with intact uterus and ovaries).

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