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Prospectively measured triiodothyronine levels are positively associated with breast cancer risk in postmenopausal women

Tosovic, Ada LU ; Bondeson, Anne-Greth LU ; Bondeson, Lennart LU ; Ericsson, Ulla-Britt; Malm, Johan LU and Manjer, Jonas LU (2010) In Breast Cancer Research 12(3).
Abstract
Introduction: The potential association between hypo-and hyperthyroid disorders and breast cancer has been investigated in a large number of studies during the last decades without conclusive results. This prospective cohort study investigated prediagnostic levels of thyrotropin (TSH) and triiodothyronine (T3) in relation to breast cancer incidence in pre- and postmenopausal women. Methods: In the Malmo Preventive Project, 2,696 women had T3 and/or TSH levels measured at baseline. During a mean follow-up of 19.3 years, 173 incident breast cancer cases were retrieved using record linkage with The Swedish Cancer Registry. Quartile cut-points for T3 and TSH were based on the distribution among all women in the study cohort. A Cox's... (More)
Introduction: The potential association between hypo-and hyperthyroid disorders and breast cancer has been investigated in a large number of studies during the last decades without conclusive results. This prospective cohort study investigated prediagnostic levels of thyrotropin (TSH) and triiodothyronine (T3) in relation to breast cancer incidence in pre- and postmenopausal women. Methods: In the Malmo Preventive Project, 2,696 women had T3 and/or TSH levels measured at baseline. During a mean follow-up of 19.3 years, 173 incident breast cancer cases were retrieved using record linkage with The Swedish Cancer Registry. Quartile cut-points for T3 and TSH were based on the distribution among all women in the study cohort. A Cox's proportional hazards analysis was used to estimate relative risks (RR), with a confidence interval (CI) of 95%. Trends over quartiles of T3 and TSH were calculated considering a P-value < 0.05 as statistically significant. All analyses were repeated for pre-and peri/postmenopausal women separately. Results: Overall there was a statistically significant association between T3 and breast cancer risk, the adjusted RR in the fourth quartile, as compared to the first, was 1.87 (1.12 to 3.14). In postmenopausal women the RRs for the second, third and fourth quartiles, as compared to the first, were 3.26 (0.96 to 11.1), 5.53 (1.65 to 18.6) and 6.87 (2.09 to 22.6), (P-trend: < 0.001). There were no such associations in pre-menopausal women, and no statistically significant interaction between T3 and menopausal status. Also, no statistically significant association was seen between serum TSH and breast cancer. Conclusions: This is the first prospective study on T3 levels in relation to breast cancer risk. T3 levels in postmenopausal women were positively associated with the risk of breast cancer in a dose-response manner. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Breast Cancer Research
volume
12
issue
3
publisher
BioMed Central
external identifiers
  • wos:000285689000009
  • scopus:78149484359
ISSN
1465-5411
DOI
10.1186/bcr2587
language
English
LU publication?
yes
id
52174554-3d39-4955-a7c8-28f451a89f32 (old id 1815005)
date added to LUP
2011-03-02 11:45:07
date last changed
2018-07-15 03:03:14
@article{52174554-3d39-4955-a7c8-28f451a89f32,
  abstract     = {Introduction: The potential association between hypo-and hyperthyroid disorders and breast cancer has been investigated in a large number of studies during the last decades without conclusive results. This prospective cohort study investigated prediagnostic levels of thyrotropin (TSH) and triiodothyronine (T3) in relation to breast cancer incidence in pre- and postmenopausal women. Methods: In the Malmo Preventive Project, 2,696 women had T3 and/or TSH levels measured at baseline. During a mean follow-up of 19.3 years, 173 incident breast cancer cases were retrieved using record linkage with The Swedish Cancer Registry. Quartile cut-points for T3 and TSH were based on the distribution among all women in the study cohort. A Cox's proportional hazards analysis was used to estimate relative risks (RR), with a confidence interval (CI) of 95%. Trends over quartiles of T3 and TSH were calculated considering a P-value &lt; 0.05 as statistically significant. All analyses were repeated for pre-and peri/postmenopausal women separately. Results: Overall there was a statistically significant association between T3 and breast cancer risk, the adjusted RR in the fourth quartile, as compared to the first, was 1.87 (1.12 to 3.14). In postmenopausal women the RRs for the second, third and fourth quartiles, as compared to the first, were 3.26 (0.96 to 11.1), 5.53 (1.65 to 18.6) and 6.87 (2.09 to 22.6), (P-trend: &lt; 0.001). There were no such associations in pre-menopausal women, and no statistically significant interaction between T3 and menopausal status. Also, no statistically significant association was seen between serum TSH and breast cancer. Conclusions: This is the first prospective study on T3 levels in relation to breast cancer risk. T3 levels in postmenopausal women were positively associated with the risk of breast cancer in a dose-response manner.},
  author       = {Tosovic, Ada and Bondeson, Anne-Greth and Bondeson, Lennart and Ericsson, Ulla-Britt and Malm, Johan and Manjer, Jonas},
  issn         = {1465-5411},
  language     = {eng},
  number       = {3},
  publisher    = {BioMed Central},
  series       = {Breast Cancer Research},
  title        = {Prospectively measured triiodothyronine levels are positively associated with breast cancer risk in postmenopausal women},
  url          = {http://dx.doi.org/10.1186/bcr2587},
  volume       = {12},
  year         = {2010},
}