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

Autor: Nyström L; 1 Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden., Bjurstam N; 2 Department of Radiology, Sahlgrenska University Hospital, Sahlgrenska Academy, Göteborg, Sweden., Jonsson H; 3 Department of Radiation Sciences, Umeå University, Umeå, Sweden., Zackrisson S; 4 Department of Clinical Sciences in Malmö, Lund University, Lund, Sweden.; 5 Diagnostic Radiology, Lund University, Lund, Sweden., Frisell J; 6 Department of Molecular Medicine and Surgery, Karolinska Institutet, Solna, Sweden.
Jazyk: angličtina
Zdroj: Journal of medical screening [J Med Screen] 2017 Mar; Vol. 24 (1), pp. 34-42. Date of Electronic Publication: 2016 Jul 07.
DOI: 10.1177/0969141316648987
Abstrakt: 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.
Databáze: MEDLINE