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| 2. |
- Agborsangaya, Calypse, et al.
(författare)
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The effects of storage time and sampling season on the stability of serum 25-hydroxy vitamin D and androstenedione
- 2010
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Ingår i: Nutrition and Cancer. - : Informa UK Limited. - 0163-5581 .- 1532-7914. ; 62:1, s. 51-57
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Tidskriftsartikel (refereegranskat)abstract
- Knowledge of the stability of serum samples stored in large biobanks is pivotal for reliable assessment of hormone-dependent disease risks. We studied the effects of sample storage time and season of serum sampling on the stability of 25-hydroxy vitamin D (25-OHD) and androstenedione in a stratified random sample of 402 women, using paired sera from the Finnish Maternity Cohort. Serum samples selected were donated between 6 and 24 yr ago. The storage time did not affect serum 25-OHD and androstenedione levels. However, there was a significant mean difference in the 25-OHD levels of sera withdrawn during winter (first sample) vs. during summer (second sample; -18.4 nmol/l, P ≤ 0.001). Also at the individual level, there were significant differences in average 25-OHD levels between individuals with the paired sera taken at winter–winter compared with other alternatives (summer–winter, winter–summer, and summer–summer). The androstenedione levels showed no such differences. Long-term storage does not affect serum 25-OHD and androstenedione levels, but sampling season is an important determinant of 25-OHD levels. Stored serum samples can be used to study disease associations with both hormones. However, sampling season needs to be taken into account for 25-OHD by considering matching and stratification and, if possible, serial sampling.
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| 3. |
- Chen, Tianhui, et al.
(författare)
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Circulating sex steroids during pregnancy and maternal risk of non-epithelial ovarian cancer
- 2011
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Ingår i: Cancer Epidemiology, Biomarkers and Prevention. - 1055-9965 .- 1538-7755. ; 20:2, s. 324-336
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Tidskriftsartikel (refereegranskat)abstract
- This is the first prospective study providing initial evidence that elevated androgens play a role in the pathogenesis of SCST. Impact: Our study may note a particular need for larger confirmatory investigations on sex steroids and NEOC. Cancer Epidemiol Biomarkers Prev; 20(2); 324-36. ©2010 AACR.
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| 4. |
- 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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| 5. |
- 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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| 6. |
- Holl, Katsiaryna, et al.
(författare)
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Effect of long-term storage on hormone measurements in samples from pregnant women : the experience of the Finnish Maternity Cohort
- 2008
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Ingår i: Acta Oncologica. - Stockholm : Taylor & Francis. - 0284-186X .- 1651-226X. ; 47:3, s. 406-412
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Tidskriftsartikel (refereegranskat)abstract
- Validity of biobank studies on hormone associated cancers depend on the extent the sample preservation is affecting the hormone measurements. We investigated the effect of long-term storage (up to 22 years) on immunoassay measurements of three groups of hormones and associated proteins: sex-steroids [estradiol, progesterone, testosterone, dihydroepiandrosterone sulphate (DHEAS), sex hormone-binding globulin (SHBG)], pregnancy-specific hormones [human chorionic gonadotropin (hCG), placental growth hormone (pGH), alpha-fetoprotein (AFP)], and insulin-like growth factor (IGF) family hormones exploiting the world largest serum bank, the Finnish Maternity Cohort (FMC). Hormones of interest were analyzed in a random sample of 154 Finnish women in the median age (29.5 years, range 25 to 34 years) of their first pregnancy with serum samples drawn during the first trimester. All hormone measurements were performed using commercial enzyme-linked- or radio-immunoassays. Storage time did not correlate with serum levels of testosterone, DHEAS, hCG, pGH and total IGFBP-1. It had a weak or moderate negative correlation with serum levels of progesterone (Spearman's ranked correlation coefficient (rs)=− 0.36), IGF-I (rs=−0.23) and IGF binding protein (BP)-3 (rs=−0.38), and weak positive correlation with estradiol (rs=0.23), SHBG (rs=0.16), AFP (rs=0.20) and non-phosphorylated IGF binding protein (BP)-1 (rs=0.27). The variation of all hormone levels studied followed the kinetics reported for early pregnancy. Bench-lag time (the time between sample collection and freezing for storage) did not materially affect the serum hormone levels. In conclusion, the stored FMC serum samples can be used to study hormone-disease associations, but close matching for storage time and gestational day are necessary design components of all related biobank studies.
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| 7. |
- Holl, Katsiaryna, et al.
(författare)
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Endogenous steroid hormone levels in early pregnancy and risk of testicular cancer in the offspring: A nested case-referent study
- 2009
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 124:12, s. 2923-2928
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Tidskriftsartikel (refereegranskat)abstract
- According to the leading hypothesis on testicular cancer (TC) etiology exposure to a specific pattern of steroid hormones in utero, in particular, to high levels of estrogens and low levels of androgens is the major determinant of TC risk in the offspring. We performed a case-referent study nested within Finnish, Swedish and Icelandic maternity cohorts exploiting early pregnancy serum samples to evaluate the role of maternal endogenous steroid hormones with regard to the risk of TC. TC cases and referents were aged between 0 and 25 years. For each case-index mother pair, three or four matched referent-referent mother pairs Were identified using national population registries. First trimester or early second trimester sera were retrieved from the index mothers of 73 TC cases and 286 matched referent mothers, and were tested for dehydroepiandrosterone sulfate (DHEAS), androstenedione, testosterone, estradiol, estrone, and sex hormone binding globulin (SHBG,). Offspring of mothers with high DHEAS levels had a significantly decreased risk of TC (OR for highest vs. lowest DHEAS quartile, 0.18 (95% CI 0.06-0.58). In contrast, offspring of mothers With high androstenedione levels had ail increased risk of TC (OR 4.1; 95% CI 1.2-12.0). High maternal total estradiol level also tended to be associated with an increased risk of TC in the offspring (OR 32; 95% CI 0.98-1,090). We report the first direct evidence that interplay or maternal steroid hormones in the early pregnancy is important in the etiology of TC in the offspring. (C) 2009 UICC
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| 8. |
- Lukanova, Annekatrin, et al.
(författare)
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Circulating estrogens and progesterone during primiparous pregnancies and risk of maternal breast cancer
- 2012
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 130:4, s. 910-920
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Tidskriftsartikel (refereegranskat)abstract
- Pregnancy reduces maternal risk of breast cancer in the long term, but the biological determinants of the protection are unknown. Animal experiments suggest that estrogens and progesterone could be involved, but direct human evidence is scant. A case-control study (536 cases and 1,049 controls) was nested within the Finnish Maternity Cohort. Eligible were primiparous women who delivered at term a singleton offspring before age 40. For each case, two individually matched controls by age (+/- 6 months) and date of sampling (+/- 3 months) were selected. Estradiol, estrone and progesterone in first-trimester serum were measured by high-performance liquid chromatography tandem mass spectrometry and sex-hormone binding globulin (SHBG) by immunoassay. Odds ratios (OR) and 95% confidence intervals (CI) were estimated through conditional logistic regression. In the whole study population there was no association of breast cancer with any of the studied hormones. In analyses stratified by age at diagnosis, however, estradiol concentrations were positively associated with risk of breast cancer before age 40 (upper quartile OR, 1.81; CI, 1.083.06), but inversely associated with risk in women who were diagnosed =age 40 (upper quartile OR, 0.64; CI, 0.401.04), pinteraction 0.004. Risk estimates for estrone mirrored those for estradiol but were less pronounced. Progesterone was not associated with risk of subsequent breast cancer. Our results provide initial evidence that concentrations of estrogens during the early parts of a primiparous pregnancy are associated with maternal risk of breast cancer and suggest that the effect may differ for tumors diagnosed before and after age 40.
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| 9. |
- 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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| 10. |
- 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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