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- Dossus, Laure, et al.
(författare)
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Reproductive risk factors and endometrial cancer : the European prospective investigation into cancer and nutrition
- 2010
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 127:2, s. 442-451
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Tidskriftsartikel (refereegranskat)abstract
- Endometrial cancer risk has been associated with reproductive factors (age at menarche, age at menopause, parity, age at first and last birth, time since last birth and use of oral contraceptives (OCs)]. However, these factors are closely interrelated and whether they act independently still requires clarification. We conducted a study to examine the association of menstrual and reproductive variables with the risk of endometrial cancer among the European Prospective Investigation into Cancer and Nutrition (EPIC). Among the 302,618 women eligible for the study, 1,017 incident endometrial cancer cases were identified. A reduction in endometrial cancer risk was observed in women with late menarche, early menopause, past OC use, high parity and a shorter time since last full-term pregnancy (FTP). No association was observed for duration of breast feeding after adjustment for number of FTP or for abortion (spontaneous or induced). After mutual adjustment, late age at menarche, early age at menopause and duration of OC use showed similar risk reductions of 7-8% per year of menstrual life, whereas the decreased risk associated with cumulative duration of FTPs was stronger (22% per year). In conclusion, our findings confirmed a reduction in risk of endometrial cancer with factors associated with a lower cumulative exposure to estrogen and/or higher exposure to progesterone, such as increasing number of FTPs and shorter menstrual lifespan and, therefore, support an important role of hormonal mechanisms in endometrial carcinogenesis.
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| 2. |
- Ritte, Rebecca, et al.
(författare)
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Reproductive factors and risk of hormone receptor positive and negative breast cancer : a cohort study
- 2013
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Ingår i: BMC Cancer. - : BioMed Central. - 1471-2407 .- 1471-2407. ; 13, s. Article Number: 584-
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Tidskriftsartikel (refereegranskat)abstract
- Background: The association of reproductive factors with hormone receptor (HR)-negative breast tumors remains uncertain. Methods: Within the EPIC cohort, Cox proportional hazards models were used to describe the relationships of reproductive factors (menarcheal age, time between menarche and first pregnancy, parity, number of children, age at first and last pregnancies, time since last full-term childbirth, breastfeeding, age at menopause, ever having an abortion and use of oral contraceptives [OC]) with risk of ER-PR-(n = 998) and ER+PR+ (n = 3,567) breast tumors. Results: A later first full-term childbirth was associated with increased risk of ER+PR+ tumors but not with risk of ER-PR-tumors (= 35 vs. = 19 years HR: 1.47 [95% CI 1.15-1.88] p(trend) < 0.001 for ER+PR+ tumors; = 35 vs. = 19 years HR: 0.93 [95% CI 0.53-1.65] p(trend) = 0.96 for ER-PR-tumors; P-het = 0.03). The risk associations of menarcheal age, and time period between menarche and first full-term childbirth with ER-PR-tumors were in the similar direction with risk of ER+PR+ tumors (p(het) = 0.50), although weaker in magnitude and statistically only borderline significant. Other parity related factors such as ever a full-term birth, number of births, age-and time since last birth were associated only with ER+PR+ malignancies, however no statistical heterogeneity between breast cancer subtypes was observed. Breastfeeding and OC use were generally not associated with breast cancer subtype risk. Conclusion: Our study provides possible evidence that age at menarche, and time between menarche and first full-term childbirth may be associated with the etiology of both HR-negative and HR-positive malignancies, although the associations with HR-negative breast cancer were only borderline significant.
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