Environment and Breast Cancer: Science Review

Evidence From Humans
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Systematic review and meta-analysis of cyclodiene insecticides and breast cancer
Khanjani, N., Hoving, J. L., Forbes, A. B., Sim, M. R. J Environ Sci Health C Environ Carcinog Ecotoxicol. 2007. 25:1, 23-52.
Topic area
Environmental pollutant - Organochlorine pesticides
Study design
Funding agency
Not supported by a specific institution
Study Participants
Number of Cases
Not reported
Menopausal Status
The menopausal status of women included in this study is listed here.
No analyses by menopausal status
Number of Controls
Not reported
Country where study was conducted
US, Canada, Finland, Denmark, Italy, Norway, India
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
Twenty-one papers presenting data from case-control or nested case-control studies, from a search of studies published 1966-2006.
Exposures investigated
Serum, plasma or adipose cyclodiene OCPs (aldrin, dieldrin, heptachlor, chlordane, endosulfan, endrin, telodrin, isodrin, toxaphene) and major metabolites/derivatives (dieldrin, heptachlor epoxide, oxychlordane, trans-nonachlor and cis-nonachlor).
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.
Varied across studies from none to extensive
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
Highest vs lowest exposure category:
Aldrin (2 studies) OR 1.55 (95% CI 1.00-2.40)
Dieldrin (5 studies) OR 1.19 (95% CI 0.89-1.61)
Oxychlordane (5 studies) OR 0.77 (95% CI 0.59-1.02)
Trans-nonachlor (6 studies) OR 0.86 (95% CI 0.69-1.09)
Cis-nonachlor (3 studies) OR 1.10 (95% CI 0.75-1.63)
Results Comments
No increased risks for ER+ and ER- tumors with trans and cis- nonachlor exposure. Pooled analyses for studies that provided geometric mean (SD) showed significantly elevated geometric mean ratio for Heptachlor (GMR = 5.32, 95% CI: 3.79-7.48) based on 2 studies, and nonsignificantly elevated geometric mean ratios for Aldrin, Dieldrin and Heptachlorepoxide.
Author address
Department of Epidemiology & Preventive Medicine, Monash University, The Alfred Hospital, Melbourne, VIC, Australia. Narges.Khanjani@med.monash.edu.au