Associations between Environmental Exposures and Incident Colorectal Cancer by ESR2 Protein Expression Level in a Population-Based Cohort of Older Women.
Cancer Epidemiol Biomarkers Prev
; 24(4): 713-9, 2015 Apr.
Article
em En
| MEDLINE
| ID: mdl-25650184
ABSTRACT
BACKGROUND:
Cigarette smoking (smoking), hormone therapy (MHT), and folate intake (folate) are each thought to influence colorectal cancer risk, but the underlying molecular mechanisms remain incompletely defined. Expression of estrogen receptor ß (ESR2) has been associated with colorectal cancer stage and survival.METHODS:
In this prospective cohort study, we examined smoking, MHT, and folate-associated colorectal cancer risks by ESR2 protein expression level among participants in the Iowa Women's Health Study (IWHS). Self-reported exposure variables were assessed at baseline. Archived, paraffin-embedded colorectal cancer tissue specimens were collected and evaluated for ESR2 protein expression by IHC. Multivariate Cox regression models were fit to estimate relative risks (RR) and 95% confidence intervals (CI) for associations between smoking, MHT, or folate and ESR2-defined colorectal cancer subtypes.RESULTS:
Informative environmental exposure and protein expression data were available for 491 incident colorectal cancer cases. Positive associations between ESR2-low and -high tumors and several smoking-related variables were noted, most prominently with average number of cigarettes per day (RR, 4.24; 95% CI, 1.81-9.91 for ESR2-low and RR, 2.15; 95% CI, 1.05-4.41 for ESR2-high for ≥40 cigarettes compared with nonsmokers). For MHT, a statistically significant association with ESR2-low tumors was observed with longer duration of exposure (RR, 0.54; 95% CI, 0.26-1.13 for >5 years compared with never use). No associations were found for folate.CONCLUSIONS:
In this study, smoking and MHT were associated with ESR2 expression patterns. IMPACT These data support possible heterogeneous effects from smoking and MHT on ERß-related pathways of colorectal carcinogenesis in older women.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Neoplasias Colorretais
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Fumar
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Terapia de Reposição Hormonal
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Receptor beta de Estrogênio
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Exposição Ambiental
Tipo de estudo:
Etiology_studies
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Incidence_studies
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Observational_studies
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Prognostic_studies
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Risk_factors_studies
Limite:
Aged
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Female
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Humans
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Middle aged
Idioma:
En
Revista:
Cancer Epidemiol Biomarkers Prev
Ano de publicação:
2015
Tipo de documento:
Article