Weight and weight changes throughout life and postmenopausal breast cancer risk: a case-control study in France

BMC Cancer

Table 3 Odds ratios of postmenopausal breast cancer for BMI at age 20, age 50 and current age, and for BMI gain from age 20 to current age, age 20 to 40, age 40 to 50, and age 50 to current age par category and per increment of 5 kg/m² of BMI or BMI gain

	Cases		Controls		OR^a	95 % CI	p trend^b
	(n = 739)		(n = 815)		OR^a	95 % CI	p trend^b
	N	%	N	%
BMI at age 20 (kg/m²)
< 18.5	146	20.3	150	19.0	1.10	[0.84-1.44]
≥ 18.5 < 25	527	73.2	587	74.2	1	ref
≥ 25	47	6.5	54	6.8	0.92	[0.60-1.41]
Per 5 kg/m ²					1.03	[0.85-1.25]	0.76
BMI at age 50 (kg/m²)
< 18.5	34	4.9	29	3.8	1.14	[0.67-1.96]
≥ 18.5 < 25	461	65.8	510	66.6	1	ref
≥ 25 < 30	147	21.0	162	21.1	1.07	[0.81-1.40]
≥ 30	59	8.4	65	8.5	1.05	[0.70-1.56]
Per 5 kg/m ²					1.07	[0.94-1.22]	0.30
Current BMI (kg/m²)
< 18.5	15	2.0	21	2.6	0.73	[0.36-1.50]
≥ 18.5 < 25	374	50.7	407	50.0	1	ref
≥ 25 < 30	223	30.3	245	30.1	1.03	[0.80-1.31]
≥ 30	125	17.0	141	17.3	1.04	[0.77-1.41]
Per 5 kg/m ²					1.03	[0.92-1.14]	0.62
BMI change from age 20 to current age (kg/m²)
< 1	139	19.3	161	20.4	1	ref
≥ 1 < 3	140	19.4	136	17.2	1.18	[0.83-1.66]
≥ 3 < 6	196	27.2	211	26.7	1.10	[0.81-1.51]
≥ 6	245	34.0	283	35.8	1.06	[0.78-1.44]
Per 5 kg/m ²					1.02	[0.91-1.14]	0.76
BMI change from age 20 to 40 (kg/m²)
< 1	306	44.0	338	43.8	1	ref
≥ 1 < 3	240	34.5	232	30.1	1.22	[0.95-1.57]
≥ 3	150	21.6	202	26.2	0.88	[0.66-1.16]
Per 5 kg/m ²					0.88	[0.74-1.06]	0.18
BMI change from age 40 to 50 (kg/m²)
< 1	329	48.2	396	52.7	1	ref
≥ 1 < 3	223	32.7	234	31.2	1.18	[0.92-1.51]
≥ 3	131	19.2	121	16.1	1.45	[1.06-1.98]
Per 5 kg/m ²					1.32	[1.05-1.65]	0.02
BMI change from age 50 to current age (kg/m²)
< 1	310	44.2	321	41.9	1	ref
≥ 1 < 3	212	30.2	240	31.3	0.95	[0.73-1.23]
≥ 3	179	25.5	205	26.8	0.97	[0.73-1.29]
Per 5 kg/m ²					1.00	[0.83-1.21]	0.97

^aOdds ratio adjusted for study area, age at reference date, age at menarche, parity, age at first full-term pregnancy, breastfeeding, family history of breast cancer, oral contraceptive use, current use of MHT, alcohol consumption, tobacco smoking, and physical activity
^bp for trend calculated from the model using BMI or BMI change as continuous variables

ISSN: 1471-2407