Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2004 Apr 17;328(7445):921-4.
doi: 10.1136/bmj.38044.666157.63. Epub 2004 Mar 10.

Incidence of breast cancer in Norway and Sweden during introduction of nationwide screening: prospective cohort study

Per-Henrik Zahl  1 , Bjørn Heine Strand, Jan Maehlen
Affiliations

Incidence of breast cancer in Norway and Sweden during introduction of nationwide screening: prospective cohort study

Per-Henrik Zahl et al. BMJ. .

Abstract

Objective: To determine whether any increase in the incidence of breast cancer in women detected by mammography is compensated for by a drop in the incidence after age 69, years when women are no longer invited for screening.

Design: Population based cohort study of incidence of breast cancer during the introduction of nationwide screening programmes.

Setting: Norway and Sweden.

Participants: All women aged above 30 years (1.4 and 2.9 million, respectively, in 2000).

Main outcome measures: Changes in age specific incidence rates of invasive breast cancer associated with the introduction of the screening programmes.

Results: As a result of screening the recorded incidence of breast cancer in women aged 50-69 years increased by 54% in Norway and 45% in Sweden. There was no corresponding decline in incidence after the age of 69 years.

Conclusions: Without screening one third of all invasive breast cancers in the age group 50-69 years would not have been detected in the patients' lifetime. This level of overdiagnosis is larger than previously reported.

PubMed Disclaimer

Figures

Fig 1
Fig 1
Age specific incidence of invasive breast cancer in Norway and for age groups 30-49, 50-69, and >69 years. From 1991 incidence rate for age group 50-69 years in Norway is split between AORH counties that started organised screening in 1996 and other counties
Fig 2
Fig 2
Age specific incidence of invasive breast cancer in Sweden and for age groups 30-49, 50-69, and >69 years. Vertical line indicates start of organised screening in Sweden (1986)
See this image and copyright information in PMC

References

    1. Boer R, Mamerdam P, de Koning H, van Oortmarssen G. Extra incidence caused by mammographic screening. Lancet 1994;343: 979. - PubMed
    1. Van den Akker-van Marle ME, Reep-van den Bergh CM, Boer R, Del Moral A, Ascunce N, de Koning HJ. Breast cancer screening in Navarra: interpretation of a high detection rate at the first screening round and low rate at the second screening round. Int J Cancer 1997;73: 464-9. - PubMed
    1. Health Council of the Netherlands. The benefit of population screening for breast cancer with mammography. Hague: Health Council of the Netherlands (Gezundheitsraad), 2002. (publication No 2002/03E).
    1. Olsen O, Gøtzsche PC. Cochrane review on screening for breast cancer with mammography. Lancet 2001;358: 1340-2. - PubMed
    1. Hakama M, Pukkala E, Söderman B, Day N. Implementation of screening as a public health policy: issue in design and evaluation. J Med Screen 1999;6: 209-16. - PubMed