Jacky Luiten

Trends in frequency and outcome of high‐risk breast lesions at CNB |57 4 Tumor characteristics of breast cancers diagnosed after diagnostic surgical excision of high‐risk lesions The 49 high‐risk lesions that were upgraded to malignancy at diagnostic surgical excision comprised 36 cases of DCIS and 13 invasive cancers (Table 4.7). The majority of these cancers were low grade DCIS or grade I invasive cancers (61.2%, 30/49, Table 4.5). The proportion of DCIS was significantly higher in this group than in women whose CNB had yielded an unequivocal malignant diagnosis (73.5%; 36/49 vs. 19.7%; 500/2,537; p <0.001) and DCIS grading was more favorable in the first group ( p <0.001). Invasive cancers were more frequently of the ductal type and more frequently showed axillary lymph node metastasis in women with proven breast cancer at CNB ( p <0.001) compared to women with high‐risk lesions at CNB (Table 4.7). Estrogen and progesterone receptor status of invasive cancers, tumor size and type of surgical treatment (breast‐conserving surgery vs. mastectomy) were comparable for both groups. In one woman, who underwent radiologic follow up of a columnar cell lesion, an invasive ductal cancer (18 mm, B&R grade II, no lymph node metastasis) was diagnosed at the previous biopsy site two years after recall. At two‐year follow‐up, no breast cancer was diagnosed in the remaining 159 women without surgical intervention for their high‐risk lesions. Table 4.7 Comparison of tumor characteristics and type of surgery among women with a high‐risk lesion versus malignancy at percutaneous biopsy. High‐risk lesion at biopsy Cancer at biopsy P ‐value Cancers 49 2537 Tumor type (%) DCIS Invasive Unknown 36 (73.5) 13 (26.5) 0 (0) 500 (19.7) 2037 (80.3) 0 (0) <0.001 DCIS grading (%) Low grade Intermediate grade High grade 24 (66.7) 11 (30.6) 1 (2.7) 79 (15.8) 181 (36.2) 240 (48.0) <0.001 Type of invasive cancer (%) Ductal Lobular Mixed ductal/lobular Other Unknown 9 (69.2) 0 (0) 0 (0) 4 (30.7) 0 (0) 1597 (78.4) 261 (12.8) 65 (3.2) 114 (5.6) 0 (0) <0.001 Tumor size of invasive cancers (%) T1a‐c T2+ Unknown 12 (92.3) 1 (7.7) 0 (0) 1622 (79.6) 411 (20.2) 4 (0.2) 0.498