Professor Roar Johnsen from NTNU. (Photo: NTNU)
Under the Norwegian Breast Cancer Screening Programme (which is part of the public health services), all women aged 50-69 are invited for mammography screening (an X-ray examination of the breast) every two years. The programme is seeking to reduce mortality from breast cancer by 30 per cent among the women invited to take part in the screening.
A research-based evaluation of the programme has been launched under the auspices of the Research Council to look at whether this objective is being achieved.
Vast amounts of data
After some delay, the research groups taking part in the evaluation may now submit applications to the Cancer Registry of Norway for access to its data.
Once all the necessary approvals and linkages are in place, the researchers will also have access to data linked to data from Statistics Norway, the Cause of Death Registry and the Medical Birth Registry of Norway, among others.
“We are pleased that the evaluation process will now come to a real start,” says Roar Johnsen, chair of the steering committee for the research-based evaluation of the Norwegian Breast Cancer Screening Programme.
In Norway, all women aged 50-69 are invited for mammography screening every two years.
Difficult to measure the impact
The programme has been discussed extensively in the Norwegian media, partly because several preliminary studies have shown that the targeted reduction in mortality has not yet been attained.
An important factor that may have affected the results is that many women were already screened regularly for breast cancer before the programme had started.
“A significant four of 10 women in the target group reported that they were already getting regular mammograms before the Norwegian Breast Cancer Screening Programme was launched,” says Elsebeth Lynge, a professor at the University of Copenhagen and member of one of the research groups evaluating the programme.
The fact that so many women had taken the initiative to get private mammograms had already brought about a tangible reduction in mortality, which makes it more difficult to quantify the specific impact of the government-funded programme.
Conclusions in 2015
The research-based evaluation of the Norwegian Breast Cancer Screening Programme will focus on these areas:
- Changes in overall mortality and mortality from breast cancer.
- Changes to the staging system as a result of the screening programme.
- Development of interval cancer.
- Estimation of the extent of overdiagnosis.
- Women’s perceptions of and experience with the screening programme.
- Financial evaluation of programme costs and cost-benefit analyses.
A total of seven research projects will be conducted, the last of which will be concluded in 2015.