Optimization of breast cancer screening: informed decisions on benefits and harms

This thesis demonstrated an association between less regular participation in breast
cancer screening and significantly lower odds of cancer detection as well as higher odds of
advanced stage cancer detection. Regular screening is key to detecting breast cancer at an
early stage. However, whereas women of both high and low SES had high non-participation
rates in organized screening, it was mostly women of high SES who participated in
opportunistic screening. To improve the efficiency of organized screening, we need
to evaluate strategies that can reach non-participating women and we must improve
recruitment efforts for women of low SES who may face barriers to screening. It was also
shown that overdiagnosis was more related to DCIS than to invasive breast cancer, and that
estimates of invasive breast cancer overdiagnosis depend on the follow-up time and age of
screening. Moving forward, we must ensure a sufficient follow-up time of at least 10 years
to obtain unbiased overdiagnosis estimates.