Environment and Breast Cancer: Science Review

Evidence From Humans
Print this page
Occupation and breast cancer risk in Polish women: a population-based case-control study
Peplonska, B., Stewart, P., Szeszenia-Dabrowska, N., Rusiecki, J., Garcia-Closas, M., Lissowska, J., Bardin-Mikolajczak, A., Zatonski, W., Gromiec, J., Brzeznicki, S., Brinton, L. A., Blair, A. Am J Ind Med. 2007. 50:2, 97-111.
Topic area
Environmental pollutant - Occupation
Study design
Population based case-control
Study Participants
Menopausal Status
The menopausal status of women included in this study is listed here.
Stratified analysis based on menopausal status
Number of Controls
Controls: 2,502
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
Eligible cases for the Polish Breast Cancer Case-Control study were women aged 20-74 living in Warsaw and Lodz, Poland when they were diagnosed with invasive and in situ breast cancer between 2000-2003. Cases were identified through hospitals and cancer registries. Controls were randomly selected using the Polish Electronic System of Population Evidence, matched by city of residence and in 5-yr age groups.
Comment about participation selection
The study employed a rapid case ascertainment system at the hospitals, which can help to improve representation of those with more aggressive cancer, who might not survive long after diagnosis.
Exposure Investigated
Exposures investigated
Industry and occupational codes were assigned to each participant for all self-reported jobs held at least 6 months. Information collected included job title, name of employer, service/manufacturing product, work activities and duties and duration of empl
How exposure was measured
Job history Questionnaire, in person
Exposure assessment comment
Job titles are often used as proxies for exposure to all of the chemicals in a particular workplace; this helps address concerns about studying individual chemicals independently, but there may be significant variation in duration and intensity of exposure to job-related chemicals between individuals classified as being part of the same industry or even the same occupation.
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.
Age, age at menarche, menopausal status, age at menopause, number of full-term births, age at first full-term birth, oral contraceptive use, breastfeeding, BMI, family history, previous mammography use, breastfeeding, city of residence, education, recreat
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
Compared to those who never worked in the job/industry for 6 months or longer:

Printing machine operators and tenders: aOR 3.1 (95% CI 1.4-7.0)
Textile apparel and furnishing machine operators and tenders: aOR 1.3 (95% CI 1.03-1.5)
Knitting and weaving machine operators and tenders: aOR 1.4 (95% CI 0.97-1.9)
Hand sewing occupations: aOR 2.0 (95% CI 1.2-3.4)
Registered nurses: aOR 0.80 (95% CI 0.6-1.1)
Hairdressers and cosmetologists: aOR 1.0 (95% CI 0.5-1.8)
Farm operators and managers: aOR 0.7 (95% CI 0.4-1.2)
Machine operators: aOR 1.2 (95% CI 1.03-1.5)
Manufacture of rubber and miscellaneous plastic products: aOR 0.9 (95% CI 0.6-1.4)
Manufacture of electronic components and accessories:
Ever: aOR 1.7 (95% CI 1.1-2.7)
≤ 10 years: aOR 1.4 (95% CI 0.8-2.4)
> 10 years: aOR 2.8 (95% CI 1.1-7.0)

Ever vs never occupationally exposed to ethylene oxide (# ever exposed not specified): aOR 0.9 (95% CI 0.6-1.4)
Results Comments
This study considered many additional job titles. We focus on (1) significant positive associations (2) if a particular job or sector was significantly associated with breast cancer in at least one study, we report results from all other studies that considered that sector, regardless of significance. It is important to note that job coding criteria generally differ across studies. General population, including both workers and non-workers, may not be an appropriate comparison group.
Author address
Department of Occupational and Environmental Epidemiology, Nofer Institute of Occupational Medicine, Lodz, Poland. beatap@imp.lodz.pl
Reviewers Comments
No notable differences when analyses were stratified by menopausal status.