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- Yang, Meng, et al.
(författare)
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Prediagnosis leukocyte telomere length and risk of ovarian cancer
- 2016
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Ingår i: Clinical Cancer Research. - : American Association for Cancer Research. - 1078-0432 .- 1557-3265. ; 22
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Introduction: Ovarian cancer is characterized by substantial genomic instability. Telomeres, which protect the physical integrity of chromosomes, are shortened by each cell division, and evidence supports that longer telomeres may reduce genomic instability. While retrospective studies generally support an inverse association of telomere length and ovarian cancer risk, the measures of telomere length after diagnosis may be influenced by treatment. Therefore, we examined the relationship between leukocyte telomere length (LTL) assessed prior to diagnosis and risk of ovarian cancer in three prospective studies. Methods: We used buffy coat samples collected from healthy participants in the Nurses' Health Study (NHS), NHSII, and the Northern Sweden Health and Disease Study (NSHDS). Women who later developed ovarian cancer were matched to one or two controls on age, menopausal status, and date of blood collection. LTL was assessed using quantitative PCR-based assays in 5 batches with coefficients of variation of 10-15%. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using conditional logistic regression, based on study-specific quartiles in controls, for each study separately. We used fixed-effects models for meta-analysis. Multivariate models adjusted for oral contraceptive use, tubal ligation, family history of ovarian cancer, parity, smoking status, and body mass index. Results: In total, there were 487 cases and 810 controls across the three studies. The mean age at blood collection ranged from 45 (NHSII) to 57 (NHS) years. In unadjusted and multivariate models, we observed a suggestion of an inverse association between LTL and ovarian cancer risk in each study, although none of the trend tests were statistically significant. In a meta-analysis of the multivariate adjusted models, women in the longest versus shortest quartile of LTL had a non-significant 26% lower risk of ovarian cancer (OR=0.74; 95%CI=0.49-1.12; p-trend=0.33). Conclusion: In this first prospective study of telomere length and ovarian cancer risk, we observed that longer leukocyte telomere length was suggestively associated with lower ovarian cancer risk. Given that serous tumors are more likely to exhibit genomic instability, we are currently evaluating the association for this subtype as well as conducting pooled analyses with common quartile cut points across studies.
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| 2. |
- Schock, Helena, 1984-
(författare)
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Hormone concentrations during pregnancy and maternal risk of epithelial ovarian cancer
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: The aim of this thesis was to study the relationship of pre-diagnostic circulating concentrations of sex steroid hormones (androgens, estradiol, 17-hydroxyprogesterone, and progesterone), growth factors (insulin-like growth factor-I (IGF-I), placental growth hormone (GH)), sex hormone binding globulin (SHBG), and anti-Müllerian hormone (AMH) with risk of epithelial ovarian cancer (EOC) overall, and by tumor invasiveness and histology. A longitudinal study was used to assess patterns of hormonal changes during a single pregnancy, and in two consecutive pregnancies.Materials & Methods: A case-control study was nested within the Finnish Maternity Cohort and the Northern Sweden Maternity Cohort. A total of 1 052 EOC cases were identified through linkages with the cancer registries in both countries. For each case, 2-3 controls were selected. Cases and controls were matched on cohort, age and date at blood draw, as well as for parity at blood draw and at diagnosis (n=2 695). Odds ratios (OR) and corresponding 95% confidence intervals [CI] were estimated using conditional logistic regression. The longitudinal study was based on 71 pregnant Finnish women, who donated blood samples in each trimester of pregnancy.Results: Higher androgen concentrations were associated with an increased risk of overall EOC (e.g., testosterone ORT3 vs. T1: 1.56 [1.30-1.87], ptrend<0.0001), while the risk of endometrioid tumors increased with higher estradiol concentrations (ORT3 vs. T1: 2.76 [1.04-7.33], ptrend=0.03). Higher IGF-I was associated with a non-significant decrease in risk for invasive (ORT3 vs. T1: 0.79 [0.62-1.02], ptrend=0.07) and endometrioid tumors (ORT3 vs. T1: 0.55 [0.28-1.07], ptrend=0.07). The inverse association between IGF-I levels and risk of invasive EOC was stronger in analyses limited to women aged <55 years at diagnosis (ORT3 vs. T1: 0.74 [0.57-0.96], ptrend=0.03). No associations were observed between pre-diagnostic progesterone, SHBG, placental GH, and AMH with EOC risk overall, or by tumor invasiveness and histology.The longitudinal study showed that hormone concentrations were more strongly correlated between consecutive trimesters of a pregnancy than between the 1st and 3rd trimesters. Further, 3rd trimester hormone concentrations can be estimated from 1st or 2nd trimester measurements.Conclusion: Higher pre-diagnostic androgens, estradiol, and IGF-I are associated with EOC risk, and associations differ by tumor invasiveness and histology.
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