Annelotte van Bommel

47 The indicator breast-contour-preserving procedure constituted the group of patients who had undergone BCPP were assessed and evaluated over time and in relation to age. Time trends of the rate of patients who had received primary BCS were compared with BCPP. All analyses were performed using SPSS 20 (IBM-SPSS Inc., Chicago). RESULTS During the study period, 61,309 patients were diagnosed and surgically treated for primary invasive breast cancer in 89 Dutch hospitals. Patient and tumor characteristics are summarized in Table 1 . The median age of the patients was 61 years, and 74% of the patients were younger than 70 years old. The majority of patients were diagnosed with invasive ductal carcinoma (81%), and most tumors were staged as T1–2 (88%) and N0 (82%). The frequencies of the treatment strategies leading to preservation of the breast contour are listed in Table 2 . In 67% of all patients, the breast contour was preserved (BCPP): 53% of all patients (n=32,520) underwent BCS as the primary and definitive surgical treatment, 5% had BCS following NAC (n=3328), and 8% (n=5023) of all patients underwent mastectomy combined with IBR. Patients who had received NAC accounted for one-tenth of all patients who had undergone BCS, while one-fifth of patients undergoing a mastectomy received IBR. Chemotherapy was administered to 41% of all patients: 5% of patients received NAC and subsequently underwent BCS, 7% of the patients received NAC and subsequently had a mastectomy, while 29% of patients received adjuvant chemotherapy. 3