Jacky Luiten

10 | Chapter 1 added value of excision biopsies in screen‐detected breast abnormalities and how these trends compare to those observed until 2010. The histopathology diagnosis obtained through biopsy sometimes reveals pre‐ malignant lesions of unknown clinical significance. These so called ‘high‐risk lesions’ are not identical to normal breast tissue, but neither fulfill the criteria of either invasive breast cancer or precursor stadia, also referred to as DCIS. They may carry an increased risk to proceed towards malignancy. 24 Chapter 4 determines the trends in frequency, management and pathology outcome of high‐ risk breast lesions found at CNB. The rate of ‘upgrade’ to DCIS or invasive carcinoma was also determined to support an evidence‐based approach for the management of high‐risk lesions. Upgrade was defined as a change of diagnosis into DCIS or invasive carcinoma at final pathology following diagnostic surgical excision for lesions, which originally were only classified as high risk lesions at SCNB. Most DCIS lesions are detected at screening mammography by the presence of microcalcifications. However, not all microcalcifications found at screening are related to underlying DCIS. Chapter 5 focuses on the trends in the detection of microcalcifications at screening mammography and the yield of these findings after recall. If DCIS is diagnosed and surgical treatment is required, accurate pre‐operative localization of the lesion is of utmost importance in order to facilitate adequate resection. In chapter 6 two methods for the localization of non‐palpable DCIS were retrospectively compared; wire‐guided localization (WGL), the current gold standard, and iodine‐125 seed guided localization (I‐125 GL). Chapter 7 describes the patterns in treatment and outcome of DCIS in the Netherlands during a period of three decades. The risk of invasive local relapse following breast‐conserving surgery with and without adjuvant radiotherapy was also evaluated. Chapter 8 provides the summary of this thesis and also provides a summary in Dutch language. The general discussion of this thesis, the future perspectives and several new initiatives and suggestions for additional clinical studies are described in chapter 9 .