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