Sophia Zackrisson
Research group manager, Principal investigator, Professor, MD
Reduced breast cancer mortality after 20+ years of follow-up in the Swedish randomized controlled mammography trials in Malmö, Stockholm, and Göteborg
Author
Summary, in English
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.
Department/s
- BioCARE: Biomarkers in Cancer Medicine improving Health Care, Education and Innovation
- Diagnostic Radiology, (Lund)
Publishing year
2017
Language
English
Pages
34-42
Publication/Series
Journal of Medical Screening
Volume
24
Issue
1
Document type
Journal article
Publisher
Royal Society of Medicine Press
Topic
- Cancer and Oncology
Keywords
- Breast cancer mortality
- Mammography
- Randomized controlled trial
- Screening
- Sweden
Status
Published
ISBN/ISSN/Other
- ISSN: 0969-1413