Table 2.

Individual associations between body size and estrogen-receptor-positive breast cancer risk, by menopausal status and HT use

	Premenopausal				Postmenopausal, current HT use				Postmenopausal, not using HT
	Cases	Person-years	HRa	95% CI	Cases	Person-years	HRb	95% CI	Cases	Person-years	HRc	95% CI
Height (in)
<65	104	96,093	1.0		887	217,680	1.0		484	170,727	1.0
65–66	144	124,035	1.10	0.86–1.42					570	178,120	1.20	1.06–1.35
≥67					328	68,919	1.19	1.05–1.36
missing	0	289			4	561			2	1037
BMI at age 18 (kg/m2)
<20	99	70,997	1.0		1081	251,998	1.0		883	299,216	1.0
20–24	127	119,627	0.77	0.59 – 1.00
≥25	17	24,989	0.51	0.31 – 0.86	88	25,018	0.87	0.70–1.08	114	35,847	1.10	0.90–1.34
missing	5	4805			50	10,144			59	14,821
BMI at baseline (kg/m2)
<25	168	150,402	1.0		707	170,986	1.0		523	194,969	1.0
≥25	75	66,602	0.94	0.71–1.24	469	107,832	1.07	0.95–1.21	488	142,483	1.21	1.07–1.37
missing	5	3414			43	8342			45	12,432
Weight change (lbs) (age 18 to baseline)
loss ≥10	163	152,687	1.0		129	29,027	1.16	0.94–1.44	108	36,401	1.35	1.05–1.73
stable					224	56,783	1.0		148	67,402	1.0
gain 10–24					811	191,026	1.11	0.95–1.28	744	231,034	1.42	1.19–1.70
gain ≥25	79	63,066	1.04	0.79–1.37
missing	6	4664			55	10,325			56	15,048
Waist-to-height ratio
<0.50	127	108,707	1.0		769	180,564	1.0		379	143,507	1.0
0.50–0.55	52	44,642	0.92	0.67–1.28					465	135,183	1.15	1.00–1.33
≥0.56					229	48,056	1.09	0.94–1.27
missing	69	67,068			221	58,541			212	71,195
BMI at 10-year follow up
<25					140	114,879	1.0		251	145,546	1.0
≥25					113	99,976	1.04	0.81–1.34	344	146,054	1.38	1.17–1.63
missing					2	51,375			4	42,689
Weight change (lbs) (baseline to 10-year follow up)
<10					167	138,882	1.0		345	183,392	1.0
≥10 gain					78	70,971	0.94	0.71-1.23	233	100,302	1.36	1.14-1.61
missing					10	56,377			21	50,594

^aAdjusted for history of benign breast disease and family history of breast cancer in a first-degree relative; age was the time metric and the model was stratified by age at baseline. ^bAdjusted for nulliparity and age at first full-term pregnancy, history of benign breast disease, family history of breast cancer in a first-degree relative, average alcohol consumption in the year prior to baseline, and neighborhood socioeconomic status; age was the time metric and the model was stratified by age at baseline. ^cAdjusted for age at menarche, nulliparity and age at first full-term pregnancy, history of benign breast disease, family history of breast cancer in a first-degree relative, and consumption of a plant-based diet; age was the time metric and the model was stratified by age at baseline. HT hormone therapy, BMI body mass index