The Swedish Two-County Trial of Mammography Screening

Breast Neoplasm Female Clinical Trial

— WE  

Official title:

The Two-County Swedish Mammography Screening Trial

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03217539
• Other study ID #: DalarnaCC
• Status: Completed
• Phase: N/A
• First received: July 11, 2017
• Last updated: February 5, 2018
• Start date: July 7, 1977
• Est. completion date: December 31, 2015

Study information

• Verified date: February 2018
• Source: Dalarna County Council, Sweden
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Population-based randomized controlled trial carried out in two Swedish counties, Dalarna and Ostergotland to find out the impact of early detection on mortality from breast cancer.

Description:

The Swedish Two-county study is a randomized controlled trial of invitation to mammography screening. The trial took place in Kopparberg (W), now called Dalarna, and Ostergotland counties in Sweden. The trial randomized 77,080 women aged 40-74 years to invitation to screening (active study population, ASP) and 55,985 women to no invitation to screening (passive study population, PSP). The trial started in 1977 in W-county and in 1978 in E-county. Women in age 40-49 years were invited to single-view mammography screening on average every 24 months, and women aged 50-74 years on average every 33 months. Approximately seven years after randomization a significant 31% decrease in breast cancer mortality was observed in the ASP group, whereupon the PSP was invited to screening once and the screening phase of the trial ended. The mortality data have been reported every two years during the follow-up period and published in peer-reviewed medical journals. The investigators have follow-up data to the Dec 31 2015. The 29-year follow-up data has been published in 2012 in Radiology. Publication of the long-term data reflects the fact that deaths avoided by early detection include some that would have occurred a considerable time later than the screening.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 133065
• Est. completion date: December 31, 2015
• Est. primary completion date: September 9, 1986
• Accepts healthy volunteers: No
• Gender: Female
• Age group: 40 Years to 74 Years

Eligibility

Inclusion criteria

• Female

• Aged 40-74

• No history of breast cancer

Exclusion criteria

• Breast cancer diagnosis prior to randomization

Related Conditions & MeSH terms

• Breast Neoplasm Female
• Breast Neoplasms

Intervention

Diagnostic Test:
• Imaging

Locations

Country	Name	City	State
n/a

Sponsors (2)

Lead Sponsor	Collaborator
Dalarna County Council, Sweden	Ostergotland County Council, Sweden

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Breast cancer death	Comparison of breast cancer mortality in the ASP versus PSP	9 years