Skip to main content

Table 5 Modifications of associationa between 24-year mean road traffic noise Lden (per 10 dB) and incidence of breast cancer by menopausal status, HT use, obesity, night work, and residential area in 22,466 nurses from the Danish Nurse Cohort

From: Long-term exposure to road traffic noise and incidence of breast cancer: a cohort study

  Breast cancer with receptor status
N = 611
ER+
N = 494
PR+
N = 393
ER+/PR+
N = 384
Number of cases HR (95% CI) Number of cases HR (95% CI) Number of cases HR (95% CI) Number of cases HR (95% CI)
Menopausal status
 Premenopausal 334 1.16 (0.97–1.38) 272 1.25 (1.02–1.52) 231 1.17 (0.95–1.45) 226 1.19 (0.96–1.48)
 Postmenopausal 277 1.18 (0.97–1.43) 222 1.21 (0.97–1.51) 162 1.26 (0.97–1.63) 158 1.23 (0.94–1.59)
p value for interaction**   0.9069   0.7135   0.6767   0.8909
HT use
 Never 390 1.16 (0.99–1.36) 319 1.21 (1.01–1.45) 256 1.18 (0.97–1.44) 254 1.19 (0.97–1.45)
 Previous 57 0.98 (0.64–1.50) 44 1.12 (0.68–1.85) 33 1.03 (0.58–1.84) 31 0.99 (0.55–1.80)
 Current 164 1.26 (0.96–1.65) 131 1.33 (0.99–1.80) 104 1.34 (0.96–1.88) 99 1.34 (0.95–1.89)
p value for interaction**   0.4685   0.6047   0.5697   0.6012
Obesity (BMI > 30 kg/m2)
 No 572 1.18 (1.03–1.35) 459 1.25 (1.07–1.45) 367 1.22 (1.03–1.45) 358 1.22 (1.03–1.46)
 Yes 39 1.03 (0.65–1.65) 35 1.04 (0.63–1.71) 26 1.03 (0.59–1.78) 26 1.03 (0.59–1.78)
p value for interaction**   0.9805   0.9489   0.7553   0.7704
Night work*
 No 473 1.16 (1.00–1.35) 386 1.21 (1.02–1.43) 317 1.22 (1.02–1.47)   1.23 (1.02–1.48)
 Yes 24 1.86 (0.97–3.57) 17 3.36 (1.48–7.63) 9 1.88 (0.59–6.00) 310 3.04 (0.80–11.60)
p value for interaction**   0.3754   0.0477*   0.3000 8 0.1585
Residential area
 Urban 77 1.30 (0.81–2.10) 67 1.24 (0.74–2.07) 50 0.95 (0.52–1.75) 49 0.96 (0.52–1.77)
 Provincial 299 1.21 (0.98–1.51) 234 1.43 (1.12–1.83) 192 1.57 (1.19–2.06) 185 1.57 (1.19–2.08)
 Rural 235 1.12 (0.94–1.33) 193 1.12 (0.92–1.35) 151 1.06 (0.85–1.31) 150 1.06 (0.86–1.32)
p value for interaction**   0.6460   0.2610   0.0811   0.0893
  1. 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 (≤ 12 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
  2. Traffic noise was entered as a continuous variable in all models as the 24-year running mean preceding diagnosis. Model 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. However, there was no adjustment for the stratification variable
  3. HT hormone therapy, BMI body mass index, ER estrogen receptor, PR progesterone receptor
  4. *Only available for 17,545 nurses
  5. **Test of the null hypothesis that the linear trends are identical, for Wald’s test for interaction