Does screening for breast cancer with mammography do more harm than good?

From: The Cochrane Collaboration

Journal rating:
rating: 98%
Study Quality:
rating: 85%

Overall Reliability

Article Quality:
rating: 70%
rating: 100%


  • Seven trials including 600,000 women


  • The paper is a systematic review / meta analysis of all relevant trials.
  • This means that the data from all similar trials has been grouped to form an overall outcome.


  • Screening leads to a reduction in breast cancer mortality of 15% but to a 30% over diagnosis and over treatment.
  • This means that for every 2000 women invited for screening throughout a 10 year period, one will have her life prolonged. However, 10 healthy women, who would not have been incorrectly diagnosed if there had not been a screening, will be diagnosed as breast cancer patients and will be treated unnecessarily.
  • Furthermore, more than 200 women will experience important psychological distress for many months because of false positive findings.


  • Undecided