Recommendations from European Breast Guidelines

Should annual vs. triennial mammography screening be used for early detection of breast cancer in women aged 50 to 69?

Recommendation

For asymptomatic women aged 50 to 69 with an average risk of breast cancer, the ECIBC's Guidelines Development Group (GDG) recommends against annual mammography screening over triennial mammography screening in the context of an organised screening programme (strong recommendation, very low certainty in the evidence).

Recommendation strength

  • Strong recommendation against the intervention
  •   Conditional recommendation against the intervention
  •   Conditional recommendation for either the intervention or the comparison
  •   Conditional recommendation for the intervention
  •   Strong recommendation for the intervention

A recommendation can be strong or conditional.

When a recommendation is strong, most women will want to follow it. When a recommendation is conditional, the majority of women want to follow it but may need more discussion with their healthcare professional first.

Justification

Overall justification

As there was not agreement within the GDG for the strength of this recommendation, voting among members took place, the results of which were: 14 members voted for ‘strong recommendation against the intervention’, three members voted for ‘conditional recommendation against the intervention’; and two members abstained

The recommendation was strong because the GDG agreed that there is a net harm (small benefits and moderate undesirable effects), large costs and annual screening is probably not feasible to implement.

Considerations

Implementation

None considered.

Monitoring and Evaluation

None considered.

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. 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 member states have cost analysis but they are in the grey literature and not publicly available, and this should be shared with the scientific community.

Evidence

Download the evidence profile

Assessment

Background

Breast cancer is the second most common cancer in the world and the most frequent cancer among women with an estimated 1.67 million new cancer cases diagnosed in 2012 (25% of all cancers) (Ferlay et al., 2013). In 2018 in, Europe, it is estimated that 250,682 women between the ages of 50 and 69 will be diagnosed with breast cancer and 50,568 will die (Ferlay, 2018).
Mammography screening has both potential benefits and harms. The Guidelines Development Group has strongly recommended in favour of screening women between the ages of 50 and 69.
Debate about the recommended interval for screening with mammography remains due to the theoretical advantage of earlier diagnosis but a potential increase in harms with shorter screening intervals. For example, the National Health Service Breast Screening Programme (NHSBSP) recommends screening every three years for women aged 50 to 70, the USPSTF recommended screening every two years for women aged 50 to 69 (Siu, 2016), while the ACS recommended annual screening between ages 45 to 54 years and every two years from age 55 and older (Myers, 2015).

Management of Conflicts of Interest (CoI): CoIs for all Guidelines Development Group (GDG) members were assessed and managed by the Joint Research Centre (JRC) following an established procedure in line with European Commission rules. GDG member participation in the development of the recommendations was restricted, according to CoI disclosure. Consequently, for this particular question, the following GDG members were recused from voting: Roberto d'Amico and Chris de Wolf. Miranda Langendam, as external expert, was also not allowed to vote, according to the ECIBC rules of procedure.
For more information please visit http://ecibc.jrc.ec.europa.eu/gdg-documents

Is the problem a priority?
Yes *
* Possible answers: ( No , Probably no , Probably yes , Yes , Varies , Don't know )
Research Evidence
Breast cancer is the second most common cancer in the world and, by far, the most frequent cancer among women with an estimated 1.67 million new cancer cases diagnosed in 2012 (25% of all cancers) (Ferlay et al., 2013). Breast cancer ranks as the fifth cause of death from cancer overall (522,000 deaths) and it is the second cause of cancer death in developed regions (198,000 deaths, 15.4%) after lung cancer. In 2018 in, Europe, it is estimated that 250,682 women between the ages of 50 and 69 will be diagnosed with breast cancer and 50,568 will die (Ferlay, 2018). Breast cancer is the fourth cancer with the highest disease burden (Tsilidis et al., 2016).
Although mammography screening is generally accepted as beneficial in reducing breast cancer mortality in women 50-69 years. The balance between benefits and harms for the different screening intervals is still debatable, with recommended periodicity varying between annual to triennial.
Additional Considerations

This question was prioritised by the GDG.

How substantial are the desirable anticipated effects?
Small *
* Possible answers: ( Trivial , Small , Moderate , Large , Varies , Don't know )
Research Evidence

Undesirable effects (additional results)
Additionally, in 2 modelling studies, triennial screening had lower false positive results (18,354 fewer to 82,900 fewer per 100,000) and lower false positive biopsies (1,289 fewer to 2,200 fewer per 100,000) than annual screening (very low quality)(Yaffe, 2015)(Vilaprinyo, 2014).
Additional Considerations

In a systematic review for the Canadian Task Force on Preventive Health Care: based on indirect evidence from different RCTs for women in the age range of 50-69 years the risk of breast cancer mortality compared to no screening, for a screening interval <24 mo (4 studies) was RR 0.86 (95%CI 0.75-0.98); and for a screening interval >=24 mo (3 studies) was RR 0.67 (95%CI 0.51-0.88) (Care, 2011).

From the Swedish two county trial, with an average screening interval of 35 months in women 50 years and older; the percentage of interval cancers during the first 12 months after the last mammogram was 13%, from 12 to <24 months was 29% and at >=24 months it was 45% (Tabár, 1987)
From a report of the U.K. NHS Breast Screening Programme (triennial screening programme): in women aged 50-64 years the rate of interval cancers per 1,000 women screened was 0.55 for <12 months, 1.13 for 12 to <24 months and 1.22 for 24 to <36 months after last mammogram (Bennett, 2011).

The GDG discussed that there would be 42 fewer deaths per 100,000 screened if annual mammography screening was done instead of triennial, as well as more breast cancer deaths averted, more QALY and fewer number of interval cancers.

The GDG agreed that there would be small benefits for annual screening compared to triennial screening.

How substantial are the undesirable anticipated effects?
Moderate *
* Possible answers: ( Large , Moderate , Small , Trivial , Varies , Don't know )
Research Evidence