Environment and Breast Cancer: Science Review


Evidence From Humans
 
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Polycyclic aromatic hydrocarbon-DNA adducts and survival among women with breast cancer
Sagiv, S. K., Gaudet, M. M., Eng, S. M., Abrahamson, P. E., Shantakumar, S., Teitelbaum, S. L., Bell, P., Thomas, J. A., Neugut, A. I., Santella, R. M., Gammon, M. D. Environ Res. 2009. 109:3, 287-91.
Topic area
Environmental pollutant - PAHs
Study design
Population-based case-control
Funding agency
NCI NIEHS
Study Participants
Number of Cases
54 deaths due to breast cancer among 722 cases of invasive breast cancer
Menopausal Status
The menopausal status of women included in this study is listed here.
Stratified analysis based on menopausal status
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
The Long Island Breast Cancer Study Project enrolled female residents of Nassau and Suffolk Counties (Long Island), NY, age 20 or older, English-speaking, newly diagnosed with in situ or invasive breast cancer in 1996-1997. Cases were identified by regional hospital pathology laboratories. This survival analysis was limited to study participants with invasive breast cancer (1273) and for whom PAH-DNA adducts were assessed in blood samples (722). Participants were followed in the National Death Index through the end of 2002 (up to 7 years).
Comment about participation selection
In the LIBCSP, giving a blood sample was positively associated with being white, ever using alcohol, ever using HRT, ever having a mammography, and lactation history. Older women and former smokers were less likely to give blood.
Exposure Investigated
Exposures investigated
PAH-DNA adducts were measured by competitive enzyme linked immunosorbent assay (ELISA) in blood samples obtained near time of diagnosis/reference. Samples with <15% inhibition were considered non-detect. Cigarette smoking was categorized as never/former/
How exposure was measured
Biological Questionnaire, in person
Exposure assessment comment
PAH-DNA adducts reflect recent exposure. Adduct measures in blood obtained after diagnosis may capture a relevant exposure period affecting survival. The relationship of PAH-DNA adducts to specific exposure sources is poorly understood, so this measure may not correctly rank the exposures relevant to disease.
Breast cancer outcome investigated
Survival, Primary 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 at diagnosis, race and ethnicity, education, religion, household income, marital status, length of residence in interview home, benign breast disease, family history, BMI, age at menarche, HRT use, age at first birth, parity, lactation history, fertil
Genetic characterization included
If the study analyzed relationships between environmental factors and inherited genetic variations, this field will be marked “Yes.” “No”, if not.
No
Strength of associations reported
Breast cancer mortality among cases, detectable vs non-detectable PAH-DNA adducts:

Overall: aHR 1.20 (95% CI 0.63-2.28)
Quartile 1: aHR 1.37 (95% CI 0.61-3.05)
Quartile 2: aHR 1.15 (95% CI 0.50-2.67)
Quartile 3: aHR 1.03 (95% CI 0.43-2.44)
Quartile 4: aHR 1.26 (95% CI 0.56-2.86)

ER+/PR+ tumors (9 deaths): aHR 1.51 (95% CI 0.33–7.02)
ER+/PR- tumors (4 deaths): aHR 0.69 (95% CI 0.13–3.77)
ER-/PR+ tumors (2 deaths): aHR 0.72 (95% CI 0.07–7.92)
ER-/PR- tumors: aHR 1.99 (95% CI 0.58–6.79)

Premenopausal: aHR 1.53 (95% CI 0.52–4.55)
Postmenopausal: aHR 1.13 (95% CI 0.51–2.51)
Results Comments
Information on hormone receptor status was incomplete; 179 cases categorized as unknown. Treatment information was available for a subgroup of 520 women. Among these women, the association between PAH-DNA adducts and breast cancer mortality was elevated among patients who underwent radiation therapy (aHR = 5.94, 95% CI: 0.80-44.38) and lower among patients who received HRT (aHR = 0.67 95% CI: 0.25-1.78).
Author address
Department of Epidemiology, School of Public Health, University of North Carolina, Chapel Hill, NC, USA. sharon.sagiv@channing.harvard.edu
Reviewers Comments
Authors note that type of treatment administered could reflect stage at diagnosis and we note that it could also reflect tumor subtype.