European guidelines on breast cancer screening and diagnosis

The decision on this recommendation takes into account the balance between desirable and undesirable effects that probably favours organised mammography screening for women aged 45 to 49 in the context of moderate certainty of the evidence.

New evidence suggested that the cost-effectiveness probably favours organised mammography screening.

This recommendation does not apply to women at higher risk of developing breast cancer, who are outside the scope of the European breast cancer guidelines.

The GDG discussed how the implementation of the intervention may be challenged depending on the number of women included in the age range considered (i.e. adding 5 years for programs that are currently screening is less feasible than adding age groups by yearly strata) and the time interval used for screening (i.e. annual vs biennial).

Organisational issues and the backlog caused by the pandemic in the last years should also be considered.

Within EC initiative on Breast Cancer, quality indicators to measure the performance of breast cancer screening programmes have been identified.

The GDG highlighted the importance of programmatic research in absence of trial data.

The GDG considered also as research priorities:

• Evaluating the effects of the intervention, time intervals, risk factors and stratification of women, as well as context specific cost-effectiveness in this age group, in particular countries or programmes that are already implementing this approach.
• Conducting studies addressing the role of other screening modalities in this population.

The conditional recommendation against annual screening was the result of the health effects that probably favour biennial screening, although the certainty of the evidence was very low.

The GDG noted that women with a strong family history may be considered for more frequent screening within screening programmes as in the United Kingdom. Other countries do more intensive surveillance for high-risk women. 

The GDG noted that there is variability in the acceptability between countries and that the current practice will impact the ease of implementation and the acceptability of this intervention to key stakeholders.

The GDG agreed that the possibility of using other imaging techniques in this subgroup of women may be relevant to consider.

Careful monitoring of interval cancer rates in this age group is warranted.

• The GDG agreed that more research on the effectiveness of the different screening intervals through comparative studies would be helpful due to the very low certainty of the evidence.
• Less information is available for certain outcomes in this age group (e.g. interval cancer).
• The GDG noted that cost-effectiveness research would be helpful to further assess this screening interval in women aged 45 to 49.
• The GDG noted that there is a lack of research on other imaging modalities between screening intervals with mammography for women of this age group.
• There was discussion in the GDG whether women with dense breasts in this age group should be screened at different intervals.
• 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 not publicly available, and this should be shared with the scientific community. This priority may apply to all other screening interval recommendations.

The recommendation was conditional due to no net health benefits with annual screening and large costs associated with it.

The GDG agreed that the possibility of using other imaging techniques in this subgroup of women may be relevant to consider.

Evaluate existing programmes that already have annual screening in place in order to have data for inter-country comparability. 

• The GDG agreed that more research on the effectiveness of the different screening intervals through comparative studies would be helpful due to the small amount of evidence available and the very low certainty of it.
• More reliable data is necessary, particularly in this age group, as the only data comes from a small trial where the mammograms were taken in 1987.
• More research on the use of other imaging modalities was deemed by the GDG to be useful in this age group.
• There was discussion in the GDG whether women with dense breasts in this age group should be screened at different intervals.
• The use of more consistent modelling studies was also highlighted.
• 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 that are not publicly available, and this should be shared with the scientific community. This priority may apply to all other screening interval recommendations.

The reason for the conditional recommendation for either the intervention or the comparison was due mainly to the improved health effects with biennial screening, but moderate savings and favourable cost-effectiveness with triennial screening.

• Examine the conditions that the GDG identified and implement according to country-priorities.
• If there is no breast cancer screening programme already in place, triennial screening may be easier to implement as compared to biennial.
• If screening in this age group is implemented (according to the conditional recommendation made by the ECIBC's GDG based on the screening ages) it is felt that it is better to have triennial screening than no screening programme at all.
• The GDG agreed that the possibility of using other imaging techniques in this subgroup of women may be relevant to consider.

• The GDG agreed that more research on the effectiveness of the different screening intervals through comparative studies, would be helpful due to the very low certainty of the evidence.
• Less information is available for certain outcomes in this age group (e.g. interval cancer) and this information should be shared.
• The GDG notes that cost-effectiveness research would be helpful to further assess this screening interval in women aged 45 to 49.
• There was discussion in the GDG whether women with dense breasts in this age group should be screened at different intervals.
• Evaluation of data on ongoing biennial opportunistic versus organised screening, particularly for this age group, and related equity issues. However, the GDG recognised that there may be difficulty and have confounding effects when comparing different strategies for opportunistic screening.
• 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 are not publicly available, and this should be shared with the scientific community.

The strong recommendation (rather than conditional) in favour of mammography screening over no mammography screening, in the context of an organised screening programme, was a result of a balance of the health effects that favours the intervention, in the context of moderate certainty in the evidence about these effects, and the cost-effectiveness of screening probably favouring the intervention. 

This recommendation does not apply to high-risk women (see recommendations for women with high breast density).

Despite being a strong recommendation, women should be provided with the information regarding benefits and harms of screening.

Future monitoring and evaluation of screening services should consider risks and benefits in the context of evolving treatment and management protocols. Monitoring and evaluation criteria have been developed within the ECIBC initiative.

• Further research on age-specific effects related to benefits and harms is needed.
• Better information/evidence about overdiagnosis is needed.
• A better understanding of the natural history of breast cancer.
• Stratification possibilities.
• Use of monitoring data to assess effectiveness (see monitoring).
• Role of breast density in stratification.

Based on the strong recommendation against annual over triennial screening and conditional recommendation of biennial over triennial screening, for the annual vs. biennial mammography screening comparison, the ECIBC's GDG agreed on a strong recommendation against annual screening without the need to discuss in detail the evidence to decision framework criteria.

The recommendation is strong because the GDG agreed that there is a net harm (small benefits and moderate undesirable effects), large costs and feasibility issues for the implementation of annual mammography screening.

• The GDG agreed that more research on the effectiveness of the different screening intervals, through comparative studies, would be helpful due to the very low certainty of the evidence.
• 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 are not publicly available, and this should be shared with the scientific community.

The GDG felt that the health effects probably favour biennial screening over triennial screening. There were moderate savings in doing triennial screening, however, neither was favoured with regards to cost effectiveness, but triennial screening was considered to be feasible.

The GDG felt that selection of the screening interval should be dependent on the resources available and sustainability of the costs of a specific country.

In contexts where screening programmes do not already exist, the GDG felt that it would be better to have a triennial screening interval than no screening programme at all.

In contexts where triennial screening interval is currently used, the GDG recognised that human resource (radiologists/radiographers) availability may determine the decision.

• 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.
• 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.
• The GDG discussed the need for improved knowledge on radiation dose and the differences that screening intervals would have on the radiation dose received by women.
• 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 are not publicly available, and this should be shared with the scientific community.

The conditional recommendation (rather than strong) in favour of mammography screening over no mammography screening, in the context of an organised screening programme, was the result of a balance of the health effects that favours mammography screening, in the context of moderate quality evidence about these effects; despite possibly important uncertainty or variability in how much women value the main outcomes.

This recommendation does not apply to high-risk women (see recommendations for women with high breast density). 

Continued screening in this age group should be guided by life expectancy.

Alternative strategies may be needed to extend screening to age groups that were screened at a younger age.

Future monitoring and evaluation of screening services should consider risks and benefits in the context of evolving treatment and management protocols.

Monitoring and evaluation criteria have been developed within the ECIBC initiative.

• Explore other treatment options such as active surveillance/monitoring.
• Further evaluation needed regarding the incremental benefits and harms of additional screening from age 70 onwards in women who have been regularly screened before age 70.
• Carry out context-specific cost-effectiveness research.

The GDG agreed that this recommendation is strong due to the large costs of annual screening, despite the very low certainty of the evidence.

The GDG does not feel that annual screening programmes are currently in place in any jurisdictions in Europe and therefore there would be no implementation considerations for this strong recommendation.

• The GDG agreed that more research on the effectiveness of the different screening intervals, through comparative studies, would be helpful due to the very low certainty of the evidence.
• 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 should include 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 not publicly available, and this should be shared with the scientific community. This priority may apply to all other screening interval recommendations.

The GDG agreed that there is a net harm and moderate costs. Additionally, annual screening is probably not acceptable to key stakeholders and it is probably not feasible to implement. 

The GDG did not feel that annual screening programmes are currently in place in any jurisdictions in Europe and therefore there would be no implementation considerations for this strong recommendation. 

• The GDG agreed that more research on the effectiveness of the different screening intervals, through comparative studies, would be helpful due to the very low certainty of the evidence.
• 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 that are not publicly available, and this should be shared with the scientific community.