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Table 3 HRs (95% CIs) for breast cancer incidence by quintile of estimated exposure among subsets for select** individual mammary gland carcinogenic compounds

From: Hazardous air pollutants and breast cancer risk in California teachers: a cohort study

Compound

Subset

N cases

Quintile of concentration

 

Quintile 1

Quintile 2

Quintile 3

Quintile 4

Quintile 5

Ptrend

Acrylamide

ER+/PR+

4,352

1 (Referent)

—a

1.01 (0.92, 1.11)

1.15 (1.06, 1.24)*

1.04 (0.96, 1.12)

0.020

Benzene

ER-/PR-

704

1 (Referent)

1.24 (0.97, 1.57)

1.10 (0.86, 1.41)

1.02 (0.79, 1.31)

1.45 (1.15, 1.83)*

0.016

Benzidine

ER+/PR+

4,352

1 (Referent)

—a

0.97 (0.83, 1.13)

1.00 (0.92, 1.07)

1.12 (1.03, 1.20)*

0.022

BMI <25

3,123

1 (Referent)

—a

0.96 (0.80, 1.16)

1.01 (0.92, 1.10)

1.19 (1.09, 1.30)*

0.001*

Carbon tetrachloride

ER+/PR+

4,352

1 (Referent)

1.03 (0.93, 1.13)

1.10 (1.00, 1.21)

1.11 (1.01, 1.22)

1.13 (1.03, 1.25)*

0.020*

 

Postmenopausal

3,604

1 (Referent)

0.96 (0.86, 1.07)

1.07 (0.97, 1.19)

1.01 (0.91, 1.12)

1.13 (1.02, 1.26)*

0.004*

HT past/never

1,052

1 (Referent)

0.96 (0.79, 1.18)

1.04 (0.85, 1.26)

1.01 (0.83, 1.23)

1.25 (1.04, 1.52)*

0.003*

BMI <25

3,123

1 (Referent)

1.07 (0.96, 1.20)

1.11 (0.99, 1.24)

1.05 (0.94, 1.18)

1.18 (1.05, 1.32)*

0.012*

Chloroprene

BMI ≥25

2,311

1 (Referent)

—a

—a

1.04 (0.91, 1.20)

1.16 (1.05, 1.27)*

0.006

Ethyl carbamate

BMI ≥25

2,311

1 (Referent)

—a

—a

1.03 (0.93, 1.15)

1.16 (1.06, 1.28)*

0.008

Ethylidene dichloride

ER+/PR+

4,352

1 (Referent)

1.05 (0.95, 1.16)

1.20 (1.09, 1.32)*

1.15 (1.05, 1.27)*

1.05 (0.95, 1.16)

0.029

HT past/never

1,052

1 (Referent)

1.09 (0.89, 1.34)

1.18 (0.96, 1.44)

1.35 (1.11, 1.64)*

1.28 (1.05, 1.56)

0.002*

4,4'-Methylene bis(2-chloroaniline)

BMI ≥25

2,311

1 (Referent)

—a

—a

1.13 (0.97, 1.31)

1.15 (1.05, 1.27)*

0.002*

Propylene oxide

Pre/ perimenopausal

1,548

1 (Referent)

1.19 (1.01, 1.40)

1.23 (1.05, 1.44)*

1.22 (1.04, 1.43)

1.15 (0.97, 1.35)

0.012

BMI <25

3,123

1 (Referent)

1.09 (0.98, 1.22)

1.16 (1.04, 1.29)*

1.04 (0.93, 1.17)

1.06 (0.95, 1.19)

0.116

Vinyl chloride

ER+/PR+

4,352

1 (Referent)

1.06 (0.96, 1.17)

1.23 (1.12, 1.35)*

1.14 (1.03, 1.25)*

1.08 (0.98, 1.19)

0.021

Postmenopausal

3,604

1 (Referent)

1.04 (0.94, 1.16)

1.14 (1.02, 1.26)*

1.08 (0.97, 1.20)

1.06 (0.95, 1.18)

0.143

HT past/never

1,052

1 (Referent)

1.05 (0.85, 1.28)

1.21 (0.99, 1.47)

1.34 (1.10, 1.63)*

1.27 (1.04, 1.54)

0.002*

HT current

2,204

1 (Referent)

1.11 (0.97, 1.27)

1.17 (1.03, 1.34)*

1.00 (0.87, 1.15)

1.01 (0.88, 1.16)

0.991

  1. Models stratified by age and adjusted for race. Quintiles based on distribution of all study participants.
  2. aQuintiles combines when a larger portion of the study participants had same concentration value.
  3. *Remains statistically significant (p < 0.05) after adjustment for multiple comparisons.
  4. **HRs for no other compounds remained statistically significant in any other subset analysis after adjustment for multiple comparisons.
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Environmental Health

ISSN: 1476-069X