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A population-based cohort study of HRT use and breast cancer in southern Sweden

Olsson, H LU ; Bladström, A LU ; Ingvar, C LU and Möller, T R LU (2001) In British Journal of Cancer 85(5). p.674-677
Abstract

The overall tumour incidence and breast cancer incidence related to hormone replacement therapy (HRT) were followed in a population-based cohort of 29 508 women, aged 25-65 when interviewed in 1990-92. By the end of the follow up in December 1999, there were 226 611 person-years of observation. A total of 1145 malignant tumours were recorded (expected 1166.6; SIR = 0.98, 95% CI 0.93-1.04). There was a small excess of breast cancer with 434 observed and 387.69 expected (SIR = 1.12, 95% CI 1.02-1.23). Among about 3 663 ever users of HRT, there was no increase in overall tumour incidence (SIR = 0.98, 95% CI 0.86-1.12) but a significant excess of breast cancer (SIR = 1.35, 95% CI 1.09-1.64) compared with never users (SIR = 1.07, 95% CI... (More)

The overall tumour incidence and breast cancer incidence related to hormone replacement therapy (HRT) were followed in a population-based cohort of 29 508 women, aged 25-65 when interviewed in 1990-92. By the end of the follow up in December 1999, there were 226 611 person-years of observation. A total of 1145 malignant tumours were recorded (expected 1166.6; SIR = 0.98, 95% CI 0.93-1.04). There was a small excess of breast cancer with 434 observed and 387.69 expected (SIR = 1.12, 95% CI 1.02-1.23). Among about 3 663 ever users of HRT, there was no increase in overall tumour incidence (SIR = 0.98, 95% CI 0.86-1.12) but a significant excess of breast cancer (SIR = 1.35, 95% CI 1.09-1.64) compared with never users (SIR = 1.07, 95% CI 0.96-1.19). Breast cancer increased with increasing duration of use and for 48-120 months use the SIR was 1.92 (95% CI 1.32-2.70). There was no significant interaction with family history of breast cancer although an independent additive effect was suggested between HRT use and family history. In a Cox regression model time to breast cancer in relation to duration of HRT use was analysed adjusting for age at menarche, age at menopause, age at first full term pregnancy, parity and age at diagnosis. A significantly higher risk was seen for longer duration of HRT use compared with never users. No increased risk is seen in women beyond 5 years after stopping HRT. There was no interaction between previous use of oral contraceptives and later HRT use.

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organization
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Contribution to journal
publication status
published
subject
keywords
Adult, Age Distribution, Aged, Breast Neoplasms, Cohort Studies, Estrogen Replacement Therapy, Female, Follow-Up Studies, Humans, Incidence, Middle Aged, Proportional Hazards Models, Regression Analysis, Risk Assessment, Sweden
in
British Journal of Cancer
volume
85
issue
5
pages
674 - 677
publisher
Nature Publishing Group
external identifiers
  • scopus:0035445681
ISSN
0007-0920
DOI
10.1054/bjoc.2001.1899
language
English
LU publication?
yes
id
1a73de50-43d4-474b-ac8c-cb56c151a363
date added to LUP
2016-09-18 12:23:58
date last changed
2017-08-06 05:10:57
@article{1a73de50-43d4-474b-ac8c-cb56c151a363,
  abstract     = {<p>The overall tumour incidence and breast cancer incidence related to hormone replacement therapy (HRT) were followed in a population-based cohort of 29 508 women, aged 25-65 when interviewed in 1990-92. By the end of the follow up in December 1999, there were 226 611 person-years of observation. A total of 1145 malignant tumours were recorded (expected 1166.6; SIR = 0.98, 95% CI 0.93-1.04). There was a small excess of breast cancer with 434 observed and 387.69 expected (SIR = 1.12, 95% CI 1.02-1.23). Among about 3 663 ever users of HRT, there was no increase in overall tumour incidence (SIR = 0.98, 95% CI 0.86-1.12) but a significant excess of breast cancer (SIR = 1.35, 95% CI 1.09-1.64) compared with never users (SIR = 1.07, 95% CI 0.96-1.19). Breast cancer increased with increasing duration of use and for 48-120 months use the SIR was 1.92 (95% CI 1.32-2.70). There was no significant interaction with family history of breast cancer although an independent additive effect was suggested between HRT use and family history. In a Cox regression model time to breast cancer in relation to duration of HRT use was analysed adjusting for age at menarche, age at menopause, age at first full term pregnancy, parity and age at diagnosis. A significantly higher risk was seen for longer duration of HRT use compared with never users. No increased risk is seen in women beyond 5 years after stopping HRT. There was no interaction between previous use of oral contraceptives and later HRT use.</p>},
  author       = {Olsson, H and Bladström, A and Ingvar, C and Möller, T R},
  issn         = {0007-0920},
  keyword      = {Adult,Age Distribution,Aged,Breast Neoplasms,Cohort Studies,Estrogen Replacement Therapy,Female,Follow-Up Studies,Humans,Incidence,Middle Aged,Proportional Hazards Models,Regression Analysis,Risk Assessment,Sweden},
  language     = {eng},
  month        = {09},
  number       = {5},
  pages        = {674--677},
  publisher    = {Nature Publishing Group},
  series       = {British Journal of Cancer},
  title        = {A population-based cohort study of HRT use and breast cancer in southern Sweden},
  url          = {http://dx.doi.org/10.1054/bjoc.2001.1899},
  volume       = {85},
  year         = {2001},
}