Jacky Luiten

54 | Chapter 4 This increase came along with a significant decrease in masses as mammographic abnormality, from 68.7% in 2014 to 56.4% in 2016 ( p <0.001; Table 4.2). CNB was performed in 5,212 of the 11,783 recalled women (44.2%), and varied between 39.2% (2014) and 48.1% (2011) through the years (Table 4.1). A majority of these biopsies comprised ultrasound guided CNB (52.1%, 2,718/5,212; 14‐18 Gauge) and SCNB (35.1%, 1,832/5,212; 9‐11 Gauge, Table 4.2). The proportions of CNB and SCNB among all percutaneous biopsy procedures were comparable for the first and last screening year (CNB: 47.2% in 2011 (366/775) vs. 50.4% in 2016 (454/901; p =0.449), SCNB: 41.0% in 2011 (318/775) vs. 34.5% in 2016 (311/901; p =0.065). The proportion of high‐risk lesions at CNB gradually increased from 3.2% (25/775) in 2011 to 9.5% (86/901) in 2016 ( p <0.001; Table 4.1). Suspicious masses and suspicious calcifications were the dominant mammographic features at recall in women with high‐risk lesions at CNB (Table 4.3). Of the 329 high‐risk lesions, 30.4% (100/329) and 55.3% (128/329) presented as a mass or calcification at screening mammography, respectively. During the multidisciplinary meetings, at which clinical, radiologic and biopsy results were correlated with each other, it was decided that additional diagnostic surgical excision was needed in 169 of the 329 women in whom high‐risk lesions were found. The proportion of recalled women who underwent CNB followed by additional excision for diagnostic purposes doubled from 1.3% in 2011 (21/1,610) to 2.7% in 2016 (51/1,881, p =0.004, Table 4.2). The proportion of high‐risk lesions at CNB that was subsequently treated with diagnostic surgical excision varied between 41.0 and 64.3% through the years, with a mean of 51.4%, (169/329). Diagnostic surgical excision for high‐risk lesions per 1,000 screens and per 100 recalls significantly increased from 0.25 in 2011 to 0.70 in 2016 ( p <0.001) and from 0.81 in 2011 to 2.50 in 2016 ( p <0.001; Table 4.1), respectively. The malignancy rate of the excisions ranged from 22.2% in 2014 (8/36) to 38.5% in 2011 (5/13; p =0.340), with 29.0% (49/169) of all excisions showing DCIS or invasive breast cancer. Table 4.3 Mammographic abnormality of high‐risk breast lesions at screening mammography. Mammographic lesion at recall n (%) High‐risk lesions, mammographic abnormality at recall, n (%)* Suspicious mass 7,634 (64.8) 100 (1.3) Suspicious calcifications 2,162 (18.3) 182 (8.4) Suspicious mass with calcifications 487 (4.1) 27 (5.5) Asymmetry 583 (4.9) 4 (0.7) Architectural distortion 870 (7.4) 11 (1.3) Other 47 (0.4) 5 (10.6) Total 11,783 329 * As proportion of total number of women recalled for this specific mammographic abnormality.