October 27, 2017
Breast cancer mortality in neighbouring European countries, with different levels of screening but similar access to treatment: trend analysis of WHO mortality database
Pr. Philippe Autier research director (International Prevention Research Institute), Mathieu Boniol senior statistician
(Northern Ireland Cancer Registry, Belfast, Northern Ireland, UK; Department of Public Health, Norwegian University of Science and Technology, Trondheim, Norway)
BMJ 2011;343:d4411 doi: 10.1136/bmj.d4411
Breast cancer mortality is compared (non-randomized comparative study) by matching countries in pairs, with the second country having introduced screening ten years later.
Northern Ireland (United Kingdom) 1990 / Republic of Ireland 2000
Sweden 1986 / Norway 1996
The Netherlands 1989 / Belgium and Flanders (Belgian region south of the Netherlands) 2001
The study concludes that breast cancer mortality declines similarly despite a significant difference in the year of introduction and participation in screening. Therefore, there is no link between screening activity and decreased mortality. Metastatic invasive cancer remains at the same rates. One of the best proofs that this screening is not effective.
Between 1989 and 2006, deaths from breast cancer decreased by 29% in Northern Ireland and by 26% in the Republic of Ireland; by 25% in the Netherlands and by 20% in Belgium and by 25% in Flanders; by 16% in Sweden and by 24% in Norway. The time trend and year of the downward inflexion was similar between Northern Ireland and the Republic of Ireland and between the Netherlands and Flanders. In Sweden, mortality rates have decreased steadily since 1972, with no downward inflexion until 2006. Countries of each pair had similar health care services and prevalence of risk factors for breast cancer mortality, but different implementation of mammography screening, with a gap of about 10-15 years.
Conclusion of the authors
The contrast between the time differences in implementation of mammography screening and the similarity in reductions in mortality between the country pairs suggest that screening did not play a direct part in the reductions in breast cancer mortality.