Environment and Breast Cancer: Science Review

Evidence From Humans
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Role of CYP1A2 polymorphisms in breast cancer risk in women
Ayari, I., Fedeli, U., Saguem, S., Hidar, S., Khlifi, S., Pavanello, S. Mol Med Rep. 2013. 7:1, 280-6.
Topic area
Environmental pollutant - PAHs
Study design
Hospital-based case-control
Funding agency
Universitá di Padova, Ricerca di Ateneo Italian A
Study Participants
Menopausal Status
The menopausal status of women included in this study is listed here.
No analysis based on menopausal status
Number of Controls
Controls: 43
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
Cases were recruited from the Centre Hospitalier Universitaire 'Farhat Hached' between October 2007 and 2008. Healthy controls were recruited from the occupational medicine service during the same time period and were matched to cases by ethnicity and gender.
Comment about participation selection
Authors note that cancer cases were significantly older than the controls, and most cases were postmenopausal
Exposure Investigated
Exposures investigated
Consumption of grilled meat and exposure to indoor pollutants, defined as self-report of at least one of the following: use of fireplace, coal, or wood-stove to heat home, or passive exposure to tobacco smoke. CYP1A2 polymorphism measured through blood sa
How exposure was measured
Questionnaire, in person Biological
Exposure assessment comment
CYP1A2 plays a key role in activating PAHs and is also involved in estrogen metabolism.
Breast cancer outcome investigated
Primary incident breast cancer
Confounders considered
Other breast cancer risk factors, such as family history, age at first birth, and hormone replacement therapy use, that were taken into account in the study.
Genetic characterization included
If the study analyzed relationships between environmental factors and inherited genetic variations, this field will be marked “Yes.” “No”, if not.
Strength of associations reported
In the case-control analysis, there was a significant negative association between CYP1A2 -3860 (G/A) variant allele and breast cancer.

In the case-only analysis, higher indoor air pollution exposure and higher grilled food intake both showed marginal (p ≥ 0.05) inverse associations with the CYP1A2 -3860 variant allele.
Author address
Metabolic Biophysics and Applied Pharmacology Laboratory, Department of Biophysics, University of Sousse, Sousse 4002, Tunisia.