| 1. |
- Chen, Tianhui, et al.
(författare)
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IGF-I during primiparous pregnancy and maternal risk of breast cancer
- 2010
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Ingår i: Breast Cancer Research and Treatment. - : Springer Science and Business Media LLC. - 0167-6806 .- 1573-7217. ; 121:1, s. 169-175
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Tidskriftsartikel (refereegranskat)abstract
- Previously, we reported that insulin-like growth factor (IGF)-I during early pregnancy is positively associated with maternal risk of breast cancer. To further explore this association, we designed a new study limited to women who donated a blood sample during their first pregnancy ending with childbirth. A case-control study was nested within the Northern Sweden Maternity Cohort in which repository since 1975, serum specimens remaining after early pregnancy screening for infectious diseases had been preserved. Study subjects were selected among women who donated a blood sample during the full-term pregnancy that led to the birth of their first child. Two hundred and forty-four women with invasive breast cancer were eligible. Two controls, matching the index case for age and date at blood donation were selected (n = 453). IGF-I was measured in serum samples on an Immulite 2000 analyzer. Conditional logistic regression was used to estimate odds ratios and 95% confidence intervals. A significant positive association of breast cancer with IGF-I was observed, with OR of 1.73 (95% CI: 1.14-2.63) for the top tertile, P < 0.009. Subgroup analyses did not indicate statistical heterogeneity of the association by ages at sampling and diagnosis or by lag time to cancer diagnosis, although somewhat stronger associations with risk were observed in women < or = age 25 at index pregnancy and for cases diagnosed within 15 years of blood donation. The results of the study add further evidence for an adverse effect of elevated IGF-I concentrations during early reproductive life on risk of breast cancer.
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| 2. |
- Chen, Tianhui, et al.
(författare)
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Maternal hormones during early pregnancy : a cross-sectional study
- 2010
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Ingår i: Cancer Causes and Control. - : Springer Science and Business Media LLC. - 0957-5243 .- 1573-7225. ; 21:5, s. 719-727
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Little is known about correlates of first-trimester pregnancy hormones as in most studies maternal hormones have been measured later in gestation. We examined the associations of maternal characteristics and child sex with first-trimester maternal concentrations of four hormones implicated in breast cancer: human chorionic gonadotropin (hCG), alpha-fetoprotein (AFP), insulin-like growth factor (IGF)-I, and IGF-II. METHODS: About 338 serum samples donated to the Northern Sweden Maternity Cohort (NSMC), 1975-2001, during the first trimester of uncomplicated pregnancies, were analyzed for the hormones of interest as a part of a case-control study. The associations of maternal characteristics and child sex with hormone concentrations were investigated by correlation, general linear regression, and multivariate regression models. RESULTS: In the first trimester, greater maternal age was inversely correlated with IGF-I and IGF-II. In comparison with women carrying their first child, already parous women had higher IGF-I but lower hCG. Greater maternal weight and smoking were inversely correlated with hCG. No differences in hormone levels by child sex were observed. CONCLUSIONS: Our analyses indicated that potentially modifiable maternal characteristics (maternal weight and smoking) influence first-trimester pregnancy maternal hormone concentrations.
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| 3. |
- Lukanova, Annekatrin, et al.
(författare)
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Human chorionic gonadotropin and alpha-fetoprotein concentrations in pregnancy and maternal risk of breast cancer : a nested case-control study.
- 2008
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Ingår i: American Journal of Epidemiology. - : Oxford University Press (OUP). - 0002-9262 .- 1476-6256. ; 168:11, s. 1284-1291
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Tidskriftsartikel (refereegranskat)abstract
- Pregnancy hormones are believed to be involved in the protection against breast cancer conferred by pregnancy. The authors explored the association of maternal breast cancer with human chorionic gonadotropin (hCG) and alpha-fetoprotein (AFP). In 2001, a case-control study was nested within the Northern Sweden Maternity Cohort, an ongoing study in which blood samples have been collected from first-trimester pregnant women since 1975. Cases (n = 210) and controls (n = 357) were matched for age, parity, and date of blood donation. Concentrations of hCG and AFP were measured by immunoassay. No overall significant association of breast cancer with either hCG or AFP was observed. However, women with hCG levels in the top tertile tended to be at lower risk of breast cancer than women with hCG levels in the lowest tertile in the whole study population and in subgroups of age at sampling, parity, and age at cancer diagnosis. A borderline-significant decrease in risk with high hCG levels was observed in women who developed breast cancer after the median lag time to cancer diagnosis (> or =14 years; odds ratio = 0.53, 95% confidence interval: 0.27, 1.03; P = 0.06). These findings, though very preliminary, are consistent with a possible long-term protective association of breast cancer risk with elevated levels of circulating hCG in the early stages of pregnancy.
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| 4. |
- Lukanova, Annekatrin, et al.
(författare)
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Insulin-like growth factor I in pregnancy and maternal risk of breast cancer
- 2006
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Ingår i: Cancer Epidemiology, Biomarkers and Prevention. - Baltimore : Waverly Press. - 1055-9965 .- 1538-7755. ; 15:12, s. 2489-2493
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Tidskriftsartikel (refereegranskat)abstract
- Background: The role of insulin-like growth factor (IGF)-I in breast cancer remains controversial, despite numerous reports on the association of the hormone with breast cancer or high-risk mammographic densities. We hypothesized that exposure to elevated IGF-I during early pregnancy, a period characterized by intense cell proliferation in the breasts and in the presence of high concentrations of sex steroids, will be associated with increased maternal risk to develop a breast malignancy. Methods: The Northern Sweden Maternity Cohort is an ongoing prospective study, collecting blood samples from first-trimester-pregnant women since 1975 as part of screening for infectious diseases. A case-control study (212 cases and 369 controls) was nested among Northern Sweden Maternity Cohort members who delivered singleton babies. RIA was used to measure IGF-I and IGF-II levels. Conditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (95% CI). Results: Breast cancer risk increased with increasing IGF-I (top tertile OR, 1.7; 95% CI, 1.1-2.7). The association was stronger among the primiparous (OR, 2.2; 95% CI, 1.1-4.4) than in the nonprimiparous women (OR, 1.4; 95% CI, 0.7-2.8). Upper-tertile risks seemed to decrease within the <28-, 28 to 33, and >33-year groups of age at sampling, from 2.5 (0.9-7.6) to 2.1 (0.9-5.0) and 1.2 (0.5-2.5), respectively. There was no association of breast cancer with first-trimester-pregnancy IGF-II. Conclusions: The study offers further evidence that IGF-I is important in breast cancer. Our findings suggest that the adverse effect of IGF-I on the breast may be stronger before the remodeling of the gland induced by a first pregnancy.
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| 5. |
- Toniolo, Paolo, et al.
(författare)
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Human chorionic gonadotropin in pregnancy and maternal risk of breast cancer
- 2010
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Ingår i: Cancer Research. - 0008-5472 .- 1538-7445. ; 70:17, s. 6779-6786
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Tidskriftsartikel (refereegranskat)abstract
- Full-term pregnancies are associated with long-term reductions in maternal risk of breast cancer, but the biological determinants of the protection are unknown. Experimental observations suggest that human chorionic gonadotropin (hCG), a major hormone of pregnancy, could play a role in this association. A case-control study (242 cases and 450 controls) nested within the Northern Sweden Maternity Cohort included women who had donated a blood sample during the first trimester of a first full-term pregnancy. Total hCG was determined on Immulite 2000 analyzer. Odds ratios (OR) and 95% confidence intervals (CI) were estimated through conditional logistic regression. Maternal breast cancer risk decreased with increasing hCG (upper tertile OR, 0.67; CI, 0.46-0.99), especially for pregnancies before age 25 (upper tertile OR, 0.41; CI, 0.21-0.80). The association diverged according to age at diagnosis: risk was reduced after age 40 (upper tertile OR, 0.60; CI, 0.39-0.91) and seemed to increase before age 40 (upper tertile OR, 1.78; CI, 0.72-4.38). Risk was reduced among those diagnosed 10 years or longer after blood draw (upper tertile OR, 0.60; CI, 0.40-0.90), but not so among those diagnosed within 10 years (upper tertile OR, 4.33; CI, 0.86-21.7). These observations suggest that the association between pregnancy hCG and subsequent maternal risk of breast cancer is modified by age at diagnosis. Although the hormone seems to be a determinant of the reduced risk around or after age 50, it might not confer protection against, or it could even increase the risk of, cancers diagnosed in the years immediately following pregnancy.
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| 6. |
- Toriola, Adetunji T., et al.
(författare)
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Free beta- human chorionic gonadotropin, total human chorionic gonadotropin and maternal risk of breast cancer
- 2014
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Ingår i: Future Oncology. - 1479-6694 .- 1744-8301. ; 10:3, s. 377-384
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Tidskriftsartikel (refereegranskat)abstract
- Background: We investigated whether the free -human chorionic gonadotropin (free -hCG) would provide additional information to that provided by total hCG alone and thus be useful in future epidemiological studies relating hCG to maternal breast cancer risk. Materials & methods: Cases (n = 159) and controls (n = 286) were a subset of our previous study within the Northern Sweden Maternity Cohort on total hCG during primiparous pregnancy and breast cancer risk. Results: The associations between total hCG (hazard ratio: 0.79; 95% CI: 0.49-1.27), free -hCG (hazard ratio: 0.85; 95% CI: 0.33-2.18) and maternal risk of breast cancer were very similar in all analyses and mutual adjustment for either one had minor effects on the risk estimates. Conclusion: In the absence of a reliable assay on intact hCG, total hCG alone can be used in epidemiological studies investigating hCG and breast cancer risk, as free -hCG does not appear to provide any additional information.
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