Annelotte van Bommel

49 The indicator breast-contour-preserving procedure Table 2. Surgical treatment strategies for patients diagnosed with invasive breast cancer, separated by year of diagnosis, age group and hospital differences. BCS BCS Mastectomy BCPP Mastectomy NAC - NAC+ IBR + IBR - TOTAL 32520 53% 3328 5% 5023 8% 67% 20438 33% Year of diagnosis 2011 5699 54% 367 3% 682 6% 63% 3905 37% 2012 7283 54% 501 4% 920 7% 64% 4801 36% 2013 7152 53% 748 6% 1102 8% 67% 4525 34% 2014 7308 53% 957 7% 1286 9% 69% 4377 31% 2015 5078 52% 755 8% 1033 11% 71% 2830 29% Age group Below 30 52 17% 39 13% 133 44% 73% 81 27% 30 - 39 619 27% 311 14% 593 26% 67% 768 34% 40 - 49 3522 39% 1084 12% 1566 17% 68% 2967 33% 50 - 59 9107 57% 1147 7% 1715 11% 75% 4089 26% 60 - 69 11281 63% 662 4% 839 5% 72% 5006 28% 70 or above 7931 51% 83 1% 175 1% 52% 7519 48% Hospitals Mean n.a. 53% n.a. 5% n.a. 8% 67% n.a. 33% Min n.a. 34% n.a. 0% n.a. 0% 47% n.a. 12% Max n.a. 67% n.a. 21% n.a. 28% 88% n.a. 53% NAC, Neo-adjuvant chemotherapy; IBR, immediate breast reconstruction; BCS, breast conserving surgery; BCPP, breast-contour-preserving procedure; n.a., not applicable. Trends over time During 2011–2015, use of BCS following NAC and mastectomy with IBR both increased, from 3 to 8% and 6 to 11% of all patients, respectively. As a result, the overall frequency of BCPP increased significantly, from 63% in 2011 to 71% in 2015 (P<0.001; Figure 1 ; Table 2 ), and the proportion of patients who underwent a mastectomy without reconstruction decreased from 37 to 29%, i.e., a relative reduction of 22%. The proportion of patients undergoing mere BCS for invasive cancer in the Netherlands remained stable during the study period. A gradual increasewas observed in the overall use of NAC, from8% in 2011 to 16% in 2015. 3