Estimated dietary dioxin exposure and breast cancer risk among women from the French E3N prospective cohort

Breast Cancer Research

Table 3 Hazard ratios for invasive breast cancer for increased intake of 0.43 pg/kg body weight/day, according to quartiles of estimated dietary dioxin exposure and hormone receptor status (n = 63,830), 1993 to 2008

		Dietary dioxin exposure (pg/kg body weight/day)
Populations ^c	/0.43	<0.98 (ref)	[0.98, 1.23]	[1.23, 1.52]	≥1.52	P -trend
Cases, n	3465	880	853	848	884
HR (95% CI)^a	1.01 (0.99, 1.03)	1.00	0.97 (0.88, 1.06)	0.96 (0.88, 1.06)	1.02 (0.92, 1.11)	0.4181
HR (95% CI)^b	1.00 (0.96, 1.05)	1.00	0.94 (0.86, 1.04)	0.93 (0.83, 1.03)	0.96 (0.85, 1.09)	0.9405
ER+/PR+ ^d
Cases, n	1596	410	388	389	409
HR (95% CI)^a	1.02 (0.98, 1.07)	1.00	0.94 (0.82, 1.08)	0.95 (0.82, 1.09)	1.00 (0.88, 1.15)	0.5328
HR (95% CI)^b	1.00 (0.93, 1.07)	1.00	0.91 (0.79, 1.06)	0.90 (0.77, 1.05)	0.94 (0.78, 1.12)	0.9678
ER+/PR- ^d
Cases, n	561	131	146	137	147
HR (95% CI)^a	1.04 (0.96, 1.13)	1.00	1.12 (0.88, 1.41)	1.05 (0.83, 1.34)	1.14 (0.90, 1.45)	0.3565
HR (95% CI)^b	1.04 (0.93, 1.17)	1.00	1.10 (0.86, 1.41)	1.03 (0.79, 1.35)	1.14 (0.84, 1.54)	0.4571
ER-/PR- ^d
Cases, n	414	109	103	104	98
HR (95% CI)^a	0.96 (0.87, 1.06)	1.00	0.93 (0.71, 1.22)	0.94 (0.72, 1.23)	0.89 (0.67, 1.16)	0.4221
HR (95% CI)^b	0.88 (0.77, 1.01)	1.00	0.86 (0.65, 1.13)	0.81 (0.60, 1.10)	0.72 (0.50, 1.02)	0.0629

^aAge-adjusted models; ^badjusted for age, height, body mass index, energy intake, education, physical activity, smoking status, menopausal status combined with use of menopausal hormone treatment, alcohol intake, age at menarche, use of oral contraceptives, use of progestin, age at menopause, age at first full-term pregnancy and number of live births, breastfeeding, family history of breast cancer, history of personal benign breast disease and mammography; ^cER-/PR+ invasive breast cancer risk was not analyzed due to small number of cases (n = 107); ^dn = 787 invasive breast cancer cases with missing hormone receptor status. HR, hazard ratio.

ISSN: 1465-542X