To determine the best screening frequency the ECIBC's Guidelines Development Group (GDG) compared 3 different frequencies (annual, biennial and triennial) against each other for each age range.

Healthcare question

Should triennial vs. biennial mammography screening be used for early detection of breast cancer in women aged 70 to 74?


For asymptomatic women aged 70 to 74 with an average risk of breast cancer, the ECIBC's Guidelines Development Group (GDG) suggests triennial mammography screening over biennial mammography screening, in the context of an organised screening programme.

Recommendation strength ­

  Conditional recommendation for the intervention

  Very low certainty of the evidence

Considerations for implementation and policy making

In countries where women have been screened for twenty years biennially and now they have to do triennial screening, this may not be acceptable and would require designing implementation strategies.

Research priorities

  1. The GDG agreed that more research on the effectiveness of the different screening intervals, comparative studies, would be helpful due to the very low certainty of the evidence.
  2. Due to the growing ageing population, the GDG believed women in the older age groups would need to have a longer follow-up in order to see how many breast cancers are detected at those ages. In addition, the GDG believed there was a need for more data on interval cancers in the varying screening intervals, as there is currently very little data on this.
  3. The GDG felt that the implications of breast density on appropriate screening intervals should be prioritised as this could be a risk modifier that may need different intervals.
  4. The GDG felt that increased cost effectiveness data, having more contextualised costs and cost-effectiveness analysis and from other settings would be helpful for future recommendations; this included checking the consistency of cost-effectiveness models with new research from trials on breast cancer screening and natural history of breast cancer disease. Also many countries have cost analysis but they are in the "grey literature" and not publicly available, and this should be shared with the scientific community.

Supporting documents