Jacky Luiten

Trends in frequency and outcome of high‐risk breast lesions at CNB |59 4 which was associated with an increase in the absolute number of columnar cell lesions during the digital screening period. 11 We found that the incidence of high‐ risk lesions at CNB continued to increase, even many years after the transition from screen‐film to digital screening mammography. Weber et al. also found that the recall rate for suspicious calcifications remained significantly higher at digital screening, resulting in a permanently higher CNB rate for these lesions per 1,000 screens, compared to the period of screen‐film mammography. 7 We observed a significant increase in the number of asymmetries as mammographic abnormality during the last three years of inclusion, as well as a significant decrease in the number of suspicious masses as reason for recall. This finding, however, does not explain the gradual increase in the proportion of high‐risk lesions, as the vast majority of these lesions presented as a suspicious mass or suspicious calcifications at screening mammography. The type of radiologic assessment at recall showed no significant changes through the years, therefore this parameter cannot explain the increase in the proportion of high‐risk lesions. A possible explanation might be the increased awareness for both the detection and report of high‐risk lesions at CNB among pathologists. 12 The four departments of pathology from which data were derived for this study did not change their scoring protocol during the study period. In 2016, a protocol for structured reporting for surgical breast specimen was introduced in the Netherlands. However, the increase of high‐risk lesion already started several years before the introduction of this protocol. The optimal management of high‐risk lesions remains a subject of debate. Falomo et al. reported serious inconsistencies in the management of these lesions at academic institutions across the United States, with surgical excision rates ranging from 39% to 95% between centers. 5 Several studies advocate radiologic imaging follow‐up for nonatypical papillomas as the malignancy rate of these lesions may be less than 2.5%, 13,14 whereas others have found that up to 33% of these lesions may prove malignant and therefore recommend complete surgical excision. 15 Considerable variation in the upgrading of flat epithelial atypia, atypical ductal hyperplasia, LCIS/atypical lobular hyperplasia and radial scar to malignancy has been reported (flat epithelial atypia: 0%‐15%, atypical ductal hyperplasia: 22%‐ 32%, LCIS/atypical lobular hyperplasia: 2%‐29%, radial scar: 0%‐23%), resulting in mixed recommendations that range from radiologic surveillance to diagnostic surgical excision of every high‐risk lesion. 16‐26 In our series, 29% of excised high‐ risk lesions proved to be malignant; 20.7% DCIS and 8.3% invasive breast cancer, respectively. Other studies report a somewhat lower likelihood of upgrading to malignancy of 20%‐22%. 18,19 However, comparisons between studies may be