Table 4.

Association^a between road traffic noise L_den and incidence of breast cancer by combination of estrogen and progesterone receptor status in 22,466 nurses from Danish Nurse Cohort

	ER+/PR+		ER+/PR-		ER-/PR+		ER-/PR-
	Number of cases	HR (95% CI)	Number of cases	HR (95% CI)	Number of cases	HR (95% CI)	Number of cases	HR (95% CI)
24 years preceding diagnosis
Linear per 10 dB	384	1.21 (1.02–1.42)*	110	1.33 (0.97–1.82)	9	1.14 (0.33–3.87)	108	0.92 (0.68–1.25)
Low < 48 dB	45	1.00	13	1.00	0	1.00	22	1.00
Medium 48–58 dB	226	1.49 (1.07–2.07)*	64	1.45 (0.78–2.69)	5	–	57	0.73 (0.43–1.22)
High > 58 dB	113	1.61 (1.11–2.34)*	33	1.51 (0.75–3.03)	4	–	29	0.88 (0.48–1.62)
10 years preceding diagnosis
Linear per 10 dB	384	1.20 (1.03–1.40)*	110	1.30 (0.98–1.74)	9	1.22 (0.40–3.72)	108	0.98 (0.74–1.29)
Low < 48 dB	51	1.00	13	1.00	0	1.00	23	1.00
Medium 48–58 dB	218	1.53 (1.11–2.09)*	61	1.65 (0.89–3.06)	5	–	59	0.85 (0.51–1.40)
High > 58 dB	115	1.61 (1.13–2.29)*	36	1.83 (0.92–3.62)	4	–	26	0.79 (0.43–1.46)
1 year preceding diagnosis
Linear per 10 dB	384	1.21 (1.05–1.39)*	110	1.07 (0.83–1.40)	8	1.15 (0.39–3.40)	108	1.10 (0.84–1.43)
Low < 48 dB	58	1.00	19	1.00	1	1.00	20	1.00
Medium 48–58 dB	212	1.42 (1.05–1.92)*	56	1.09 (0.64–1.87)	4	1.02 (0.11–9.59)	61	1.14 (0.67–1.92)
High > 58 dB	114	1.53 (1.09–2.15)*	35	1.27 (0.69–2.34)	3	1.35 (0.13–14.4)	27	1.09 (0.59–2.03)

Abbreviations: ER Estrogen receptor, PR Progesterone receptor

^aModel adjusted for birth cohort, urbanization (urban, provincial, rural), body mass index (underweight, normal, overweight, obese), leisure time physical activity (low, medium, high), alcohol consumption (low, moderate, heavy), age at menarche (≤ years of age, > 12 years of age), parity (nulliparous, parous), number of births, age at first birth, menopausal status (premenopausal, postmenopausal), use of hormone therapy (never, past, current), use of oral contraceptives (never, ever) and smoking status

*p value <0.05