Preterm delivery is associated with an increased risk of epithelial ovarian cancer among parous women.
Int J Cancer
; 143(8): 1858-1867, 2018 10 15.
Article
en En
| MEDLINE
| ID: mdl-29737528
ABSTRACT
Epithelial ovarian cancer is a fatal disease of largely unknown etiology. Higher parity is associated with reduced risk of ovarian cancer. However, among parous women, the impact of pregnancy-related factors on risk is not well understood. This population-based case-control study included all parous women with epithelial ovarian cancer in Denmark, Finland, Norway and Sweden during 1967-2013 (n = 10,957) and up to 10 matched controls (n = 107,864). We used conditional logistic regression to estimate odds ratios (ORs) with 95% confidence intervals (CIs) for pregnancy-related factors and ovarian cancer risk by histological subtype. Preterm delivery was associated with an increased risk [pregnancy length (last pregnancy) ≤30 vs. 39-41 weeks, OR 1.33 (95% CI 1.06-1.67), adjusted for number of births]; the OR increased as pregnancy length decreased (p for trend < 0.001). Older age at first and last birth was associated with a decreased risk [first birth 30-39 vs. <25 years adjusted OR 0.76 (95% CI 0.70-0.83); last birth 30-39 vs. <25 years adjusted OR 0.76 (95% CI 0.71-0.82)]. Increasing number of births was protective [≥4 births vs. 1; OR 0.63 (95% CI 0.59-0.68)] for all subtypes, most pronounced for clear-cell tumors [OR 0.30, (95% CI 0.21-0.44), pheterogeneity < 0.001]. No associations were observed for multiple pregnancies, preeclampsia or offspring size. In conclusion, in addition to high parity, full-term pregnancies and pregnancies at older ages were associated with decreased risk of ovarian cancer. Our findings favor the cell clearance hypothesis, i.e. a recent pregnancy provides protection by clearing of precancerous cells from the epithelium of the ovary/fallopian tubes, mediated by placental or ovarian hormones.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Neoplasias Ováricas
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Nacimiento Prematuro
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Carcinoma Epitelial de Ovario
Tipo de estudio:
Etiology_studies
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Observational_studies
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Prognostic_studies
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Risk_factors_studies
Límite:
Adult
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Aged
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Female
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Humans
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Middle aged
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Pregnancy
País/Región como asunto:
Europa
Idioma:
En
Revista:
Int J Cancer
Año:
2018
Tipo del documento:
Article
País de afiliación:
Suecia