Environment and Breast Cancer: Science Review

Adipose concentrations of organochlorine compounds and breast cancer recurrence in Long Island, New York
Muscat, J. E., Britton, J. A., Djordjevic, M. V., Citron, M. L., Kemeny, M., Busch-Devereaux, E., Pittman, B., Stellman, S. D. Cancer Epidemiology, Biomarkers and Prevention. 2003. 12:12, 1474-8.

Topic area
Environmental pollutant - Pesticide, organochlorine, PCB, DDE, DDT, HCB, HCH
Environmental pollutant - Pesticide, organochlorine, PCB, DDE, DDT, HCB, HCH
Study design
Retrospective cohort
Retrospective cohort
Funding agency
NCI
NCI

Study Participants
Number of Cases
30 recurrent cases
30 recurrent cases
Menopausal Status
Post menopausal
The menopausal status of women included in this study is listed here.
Pre menopausalPost menopausal
Number in Cohort
Cohort: 194
Cohort: 194
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
A random selection of cases from the parent study, women previously diagnosed with breast cancer at one of two Long Island hospitals. A larger hospital based case control study is described in Stellman et al, 2000.

Exposure Investigated
Exposures investigated
Breast adipose tissue concentrations of PCB (congeners BZ 74, 99, 118, 138, 146, 153, 156, 167, 170, 172, 178, 180, 183, 187), DDE, DDT, HCB, HCH, oxychlordane, t-nonachlor.
Breast adipose tissue concentrations of PCB (congeners BZ 74, 99, 118, 138, 146, 153, 156, 167, 170, 172, 178, 180, 183, 187), DDE, DDT, HCB, HCH, oxychlordane, t-nonachlor.
How exposure was measured
Biological
Biological
Exposure assessment comment
A single measure of breast adipose tissue pesticide concentration close to the time of diagnosis may not be representative of the etiologic pesticide dose.
A single measure of breast adipose tissue pesticide concentration close to the time of diagnosis may not be representative of the etiologic pesticide dose.
Breast cancer outcome investigated
Breast cancer recurrence or progression
Breast cancer recurrence or progression
Ethnic groups with separate analysis
If this study provided a separate analysis by ethnic or racial group, the groups are listed here.
No
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, BMI, education, stage of disease, Tamoxifen treatment.
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
Analysis included: proportional hazard models were fit to estimate the relative risks and corresponding 95% CIs of breast cancer recurrence in relation to log-transformed concentrations of OCs.
RR of breast cancer recurrence associated with breast adipose concentration of total PCB (by tertile): 1, 0.9 (95% CI: 0.3-2.6), 2.9 (95% CI: 1.02-8.2).
There is also a suggestive increasing risk for many individual PCB congeners, although highest tertile is only significant for BZ 118 (RR = 4, 95% CI:1.32-4.9), BZ 153 (RR = 2.6, 95% CI:1.0-7.1), and BZ 167 (RR = 3.1, 95% CI:1.0-9.3).
The middle tertile for total pesticides is significantly increased (RR = 2.5, 95% CI:1.0-6.4), although the highest tertile is not (RR = 1.3, 95% CI:0.4 - 4.0).
Also, non-significant increase in risk of recurrence among smokers (RR = 2.1, 95% CI: 0.9-5.1).
Analysis included: proportional hazard models were fit to estimate the relative risks and corresponding 95% CIs of breast cancer recurrence in relation to log-transformed concentrations of OCs.
RR of breast cancer recurrence associated with breast adipose concentration of total PCB (by tertile): 1, 0.9 (95% CI: 0.3-2.6), 2.9 (95% CI: 1.02-8.2).
There is also a suggestive increasing risk for many individual PCB congeners, although highest tertile is only significant for BZ 118 (RR = 4, 95% CI:1.32-4.9), BZ 153 (RR = 2.6, 95% CI:1.0-7.1), and BZ 167 (RR = 3.1, 95% CI:1.0-9.3).
The middle tertile for total pesticides is significantly increased (RR = 2.5, 95% CI:1.0-6.4), although the highest tertile is not (RR = 1.3, 95% CI:0.4 - 4.0).
Also, non-significant increase in risk of recurrence among smokers (RR = 2.1, 95% CI: 0.9-5.1).
Results Comments
Association of PCBs with breast cancer recurrence. This significant increase was seen with only 30 recurrent cases after only 3.6 years. Although associations are seen for several individual PCB congeners, there is no controlling for the effect of the other congeners, and they are probably correlated, so it is not clear if they are all equally important.
Association of PCBs with breast cancer recurrence. This significant increase was seen with only 30 recurrent cases after only 3.6 years. Although associations are seen for several individual PCB congeners, there is no controlling for the effect of the other congeners, and they are probably correlated, so it is not clear if they are all equally important.

Author address
Institute for Cancer Prevention, Valhalla, New York 10595, USA. jmuscat@ifcp.us
Institute for Cancer Prevention, Valhalla, New York 10595, USA. jmuscat@ifcp.us