Advanced

Reduced breast cancer mortality after 20+ years of follow-up in the Swedish randomized controlled mammography trials in Malmö, Stockholm, and Göteborg

Nyström, Lennarth; Bjurstam, Nils; Jonsson, Håkan; Zackrisson, Sophia LU and Frisell, Jan (2017) In Journal of Medical Screening 24(1). p.34-42
Abstract
Objective: To analyze the age- and trial-specific effects of the breast cancer screening trials with mammography in Malmö, Stockholm, and Göteborg. Methods: The original trial files were linked to the Swedish Cancer and Cause of Death Registers to obtain date of breast cancer diagnosis and date and cause of death. Relative risks and 95% confidence intervals were calculated using the evaluation model (only breast cancers diagnosed between date of randomization and date when the first screening round of the control group was completed were included in the analysis). Results: Women aged 40–70 at randomization in the Malmö I and II, Stockholm, and Göteborg trials were followed-up for an average of 30, 22, 25, and 24 years, respectively. The... (More)
Objective: To analyze the age- and trial-specific effects of the breast cancer screening trials with mammography in Malmö, Stockholm, and Göteborg. Methods: The original trial files were linked to the Swedish Cancer and Cause of Death Registers to obtain date of breast cancer diagnosis and date and cause of death. Relative risks and 95% confidence intervals were calculated using the evaluation model (only breast cancers diagnosed between date of randomization and date when the first screening round of the control group was completed were included in the analysis). Results: Women aged 40–70 at randomization in the Malmö I and II, Stockholm, and Göteborg trials were followed-up for an average of 30, 22, 25, and 24 years, respectively. The overview of all trials resulted in a significant decrease of 15% in breast cancer mortality. The variation by consecutive 10-year age group at randomization was small—from 21% in the age group 40–49 to 11% in the age group 50–59. After adjustment for age, there was a significant reduction in breast cancer mortality in the Göteborg trial (26%), and a non-significant reduction in the Malmö I and II and Stockholm trials (12%, 15%, and 5.8%, respectively). Conclusions: The overview showed a 15% significant relative reduction in breast cancer mortality due to invitation to mammography screening. Heterogeneity in age, trial time, attendance rates, and length of screening intervals may have contributed to the variation in effect between the trials. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Breast cancer mortality, Mammography, Randomized controlled trial, Screening, Sweden
in
Journal of Medical Screening
volume
24
issue
1
pages
9 pages
publisher
Royal Society of Medicine Press
external identifiers
  • scopus:85016209129
  • wos:000394754200006
ISSN
0969-1413
DOI
10.1177/0969141316648987
language
English
LU publication?
yes
id
143e5afe-9cfe-48bc-8eeb-1240fec69538
date added to LUP
2017-04-19 10:14:50
date last changed
2018-08-12 04:35:24
@article{143e5afe-9cfe-48bc-8eeb-1240fec69538,
  abstract     = {Objective: To analyze the age- and trial-specific effects of the breast cancer screening trials with mammography in Malmö, Stockholm, and Göteborg. Methods: The original trial files were linked to the Swedish Cancer and Cause of Death Registers to obtain date of breast cancer diagnosis and date and cause of death. Relative risks and 95% confidence intervals were calculated using the evaluation model (only breast cancers diagnosed between date of randomization and date when the first screening round of the control group was completed were included in the analysis). Results: Women aged 40–70 at randomization in the Malmö I and II, Stockholm, and Göteborg trials were followed-up for an average of 30, 22, 25, and 24 years, respectively. The overview of all trials resulted in a significant decrease of 15% in breast cancer mortality. The variation by consecutive 10-year age group at randomization was small—from 21% in the age group 40–49 to 11% in the age group 50–59. After adjustment for age, there was a significant reduction in breast cancer mortality in the Göteborg trial (26%), and a non-significant reduction in the Malmö I and II and Stockholm trials (12%, 15%, and 5.8%, respectively). Conclusions: The overview showed a 15% significant relative reduction in breast cancer mortality due to invitation to mammography screening. Heterogeneity in age, trial time, attendance rates, and length of screening intervals may have contributed to the variation in effect between the trials.},
  author       = {Nyström, Lennarth and Bjurstam, Nils and Jonsson, Håkan and Zackrisson, Sophia and Frisell, Jan},
  issn         = {0969-1413},
  keyword      = {Breast cancer mortality,Mammography,Randomized controlled trial,Screening,Sweden},
  language     = {eng},
  number       = {1},
  pages        = {34--42},
  publisher    = {Royal Society of Medicine Press},
  series       = {Journal of Medical Screening},
  title        = {Reduced breast cancer mortality after 20+ years of follow-up in the Swedish randomized controlled mammography trials in Malmö, Stockholm, and Göteborg},
  url          = {http://dx.doi.org/10.1177/0969141316648987},
  volume       = {24},
  year         = {2017},
}