Population screening and intensity of screening are associated with reduced breast cancer mortality: evidence of efficacy of mammography screening in Australia



Efficacy of breast screening may differ in practice from the results of randomized trials. We report one of the largest case–control evaluations of a screening service.


Subjects included 491 breast-cancer deaths affecting 45–80-year-old South Australian females during 2002–2005 (diagnosed after BreastScreen commencement) and 1,473 live controls (three per death) randomly selected from the State Electoral Roll after birth-date matching. Cancer Registry and BreastScreen records provided cancer and screening details. Risk estimates were calculated by BreastScreen participation, using conditional logistic regression. Interpretation was assisted by a population survey of risk factor prevalence by BreastScreen participation in 1,684 females aged ≥40 years.


The relative odds (OR) (95% confidence limits) of breast-cancer death in BreastScreen participants compared with non-participants were 0.59 (0.47, 0.74). Compared with non-participants, the OR was 0.70 (0.47, 1.05) for women last screened through BreastScreen more than 3 years before diagnosis of the index case, and 0.57 (0.44, 0.72) for women screened more recently. The OR of 0.47 (0.34, 0.65) for women screened more frequently in the pre-diagnosis phase was lower than the 0.64 (0.50, 0.82) for other screened women. The overall OR of 0.59 approximated 0.70 when corrected for the screening self-selection bias observed in five randomized trials. However, multivariable analysis of survey data did not indicate a lower prevalence of breast-cancer risk factors among BreastScreen participants, suggesting that this correction may be inappropriate.


Participation in screening was associated with a breast-cancer mortality reduction of between 30 and 41%, depending on assumptions about screening self-selection bias. A downward mortality risk by recency of last screen prior to cancer diagnosis, and frequency of recent screening, is consistent with a screening effect.

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  1. 1.

    Demissie K, Mills OF, Rhoads GG (1998) Empirical comparison of the results of randomised controlled trials and case-control studies in evaluating the effectiveness of screening mammography. J Clin Epidemiol 51:81–91

    PubMed  Article  CAS  Google Scholar 

  2. 2.

    Shapiro S, Venet W, Strax P, Venet L, Roeser R (1985) Selection, follow-up and analysis in the health insurance plan study: a randomised trial with breast cancer screening. Natl Cancer Inst Monogr 67:65–74

    PubMed  CAS  Google Scholar 

  3. 3.

    Andersson I, Aspegren K, Janzon L et al (1988) Mammographic screening and mortality from breast cancer: the Malmo mammographic screening trial. BMJ 297:943–948

    PubMed  CAS  Article  Google Scholar 

  4. 4.

    Tabar L, Fagerberg G, Duffy S, Day N, Gas A, Grontoft O (1998) Update of the Swedish two county program of mammographic screening trial. Radiol Clin North Am 51:81–91

    Google Scholar 

  5. 5.

    Roberts MM, Alexander FE, Anderson TJ et al (1990) Edinburgh trial of screening for breast cancer: mortality at seven years. Lancet 335:241–246

    PubMed  Article  CAS  Google Scholar 

  6. 6.

    Miller AB, Baines CJ, To T, Wall C (1992) Canadian national breast screening study, 1: breast cancer detection and death rates among women aged 40 to 49 years. Can Med Assoc J 147:1459–1476

    CAS  Google Scholar 

  7. 7.

    Miller AB, Baines CJ, To T, Wall C (1992) Canadian national breast screening study, 2: breast cancer detection and death rates among women aged 50 to 59 years. Can Med Assoc J 147:1477–1488

    CAS  Google Scholar 

  8. 8.

    Frisell J, Eklund G, Hellstrom L, Lidbrink E, Rutqvist LE, Somell A (1991) Randomized study of mammography screening: preliminary report on mortality in the Stockholm trial. Breast Cancer Res Treat 18:49–56

    PubMed  Article  CAS  Google Scholar 

  9. 9.

    Nystrom L, Rutqvist LE, Wall S et al (1993) Breast cancer screening with mammography: overview of Swedish randomised trials. Lancet 341:973–978

    PubMed  Article  CAS  Google Scholar 

  10. 10.

    World Health Organization (WHO), International Agency for Research on Cancer (IARC) (2002) IARC handbooks of cancer prevention, vol 7: breast cancer screening. IARC Press, Lyon

    Google Scholar 

  11. 11.

    Gabe R, Duffy SW (2005) Evaluation of service screening mammography in practice: the impact on breast cancer mortality. Ann Oncol 16(Suppl 2):ii153–ii162

    PubMed  Article  Google Scholar 

  12. 12.

    Fielder HM, Warwick J, Brook D et al (2004) A case-control study to estimate the impact on breast cancer death of the breast screening programme in Wales. J Med Screen 11:194–198

    PubMed  Article  CAS  Google Scholar 

  13. 13.

    South Australian Cancer Registry (1996) Epidemiology of cancer in South Australia. Incidence, mortality and survival, 1977 to 1995. Incidence and mortality, 1995. Openbook Publishers, Adelaide

    Google Scholar 

  14. 14.

    Roder D (2006) Population screening—opportunities to strengthen cancer control. Public Health Bull S Aust 5:2–6

    Google Scholar 

  15. 15.

    Walter SD (2003) Mammographic screening: case-control studies. Ann Oncol 14:1190–1192

    PubMed  Article  CAS  Google Scholar 

  16. 16.

    Armitage P, Berry G (1987) Statistical methods in medical research, 2nd edn. Blackwell Scientific Publications, Oxford

    Google Scholar 

  17. 17.

    StataCorp (2005) Stata statistical software. Release 9.2. StatCorp LP, College Station, TX

  18. 18.

    Elmore JG, Reisch LM, Barton MB et al (2005) Efficacy of breast cancer screening in the community according to risk level. J Natl Cancer Inst 97:1035–1043

    PubMed  Article  Google Scholar 

  19. 19.

    Australian Bureau of Statistics (1998) 1996 census of population and housing. Socio-economic indexes for areas. Australian Bureau of Statistics, Canberra

    Google Scholar 

  20. 20.

    Department of Health and Aged Care and the University of Adelaide (1999) Measuring remoteness: accessibility/remoteness index of Australia (ARIA). Occasional Papers: New Series No. 6. Commonwealth of Australia, Canberra

  21. 21.

    Government of South Australia, Department of Health, Population Research and Outcomes Studies Unit (2006) Health Monitor, July and September, 2006. BreastScreen data report. Department of Health, Adelaide

  22. 22.

    Duffy SW, Hill C, Esteve J (eds) (2001) Quantitative methods for the evaluation of cancer screening. Oxford University Press, New York

    Google Scholar 

  23. 23.

    Friedman DR, Dubin N (1991) Case-control evaluation of breast cancer screening. Am J Epidemiol 133:974–984

    PubMed  CAS  Google Scholar 

  24. 24.

    Sasco AJ, Day NE, Walter SD (1986) Case-control studies for the evaluation of screening. J Chronic Dis 39:399–405

    PubMed  Article  CAS  Google Scholar 

  25. 25.

    Morrison AS (1982) Case definition in case-control studies of the efficacy of screening. Am J Epidemiol 115:6–8

    PubMed  CAS  Google Scholar 

  26. 26.

    Rhoads GG (1986) Use of case-control studies for evaluation of preventive health care. J Ambul Care Manage 9:53–64

    PubMed  CAS  Google Scholar 

  27. 27.

    Weiss NS (1983) Control definition in case-control studies of efficacy of screening and diagnostic testing. Am J Epidemiol 118:457–460

    PubMed  CAS  Google Scholar 

  28. 28.

    Weiss NS (1994) Application of the case-control method in the evaluation of screening. Epidemiol Rev 16:102–108

    PubMed  CAS  Google Scholar 

  29. 29.

    Weiss N (1999) Case-control studies of the efficacy of screening tests to prevent the incidence of cancer. Am J Epidemiol 149:1–4

    PubMed  CAS  Google Scholar 

  30. 30.

    Broeders MJ, Verbeek AL, Straatman H et al (2002) Repeated mammographic screening reduces breast cancer mortality along the continuum of age. J Med Screen 9:163–167

    PubMed  Article  CAS  Google Scholar 

  31. 31.

    Feig SA (1996) Methods to identify benefit from mammographic screening in women aged 40–49 years. Editorial. Radiology 201:309–316

    CAS  Google Scholar 

  32. 32.

    Duffy SW, Cuzick J, Tabar L et al (2002) Correcting for non-compliance bias in case-control studies to evaluate cancer screening programmes. Appl Stat 51:235–243

    Google Scholar 

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The authors are indebted to Jill Rogers of BreastScreen South Australia and Jennifer Owen of The Cancer Council South Australia for extracting the data required for this study from source records.

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Correspondence to D. Roder.

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Roder, D., Houssami, N., Farshid, G. et al. Population screening and intensity of screening are associated with reduced breast cancer mortality: evidence of efficacy of mammography screening in Australia. Breast Cancer Res Treat 108, 409–416 (2008). https://doi.org/10.1007/s10549-007-9609-5

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  • Population screening
  • Breast neoplasm
  • Breast cancer mortality
  • Mammography
  • Self-selection bias