Mammography is the only approved method for breast cancer screening, but not all tumors can be detected with mammography. The main reason is overlapping structures that can either mimic or hide a tumor on a 2-dimensional image like mammography. Digital breast tomosynthesis, (DBT) is a 3-dimensional x-ray technique that has been developed during the last years. A tomographic technique like DBT, which reduces or eliminates the detrimental effect of over- and underlying tissue, can probably help to find more tumors. This study aims to investigate whether more breast cancers can be detected with DBT compared to full field digital mammography (FFDM) in population invited to screening. An interim analysis will be performed during 2013 including the first 7,500 women of the study cohort.