Annelotte van Bommel

165 General discussion and future perspectives encompasses multiple treatment strategies that preserve or restore the contour of the breast, i.e. upfront breast conserving surgery, breast conserving surgery following neo-adjuvant chemotherapy and mastectomy followed by immediate breast reconstruction (IBR). While the rate of breast conserving surgery as primary treatment for breast cancer remained stable over time, the proportion of patients undergoing BCPP increased from 63% in 2011 to 71% in 2015: both the rates of breast conserving surgery following neo-adjuvant chemotherapy andmastectomy combined with IBR increased. The BCPP rate was similar for most age groups, but the means by which the breast contour was maintained varied largely between these groups. An increased use of primary breast conserving surgery in the elderly, and a concomitant decrease in older patients treated with neo-adjuvant chemotherapy or postmastectomy IBR was found. On average, IBRwas performed in 17%of all patients who underwent amastectomy and this proportion ranged between 0% and 64% in the 92 hospitals. This observed hospital variation in the use of IBR was the basis for the research in Chapters 4, 5 and 6 into possible patient, tumor, hospital and physicians’ factors explaining this variation. Following case-mix correction (for patient and tumor factors that were associatedwith a higher rate of IBR such as young age, multifocality, small tumor size, lowmalignancy grade, absence of lymph node involvement), large variation remained between the hospitals (0%to 43%; Chapter 4 ). Hence, hospital organizational factors were collected and compared for all hospitals in theNetherlands ( Chapter 5 ). Factors favoring theuptakeof IBR related to theobserved variation in the institutional IBR rate were: hospital type (district hospitals more frequently performed IBR compared to university hospitals), more plastic surgeons involved in reconstructive breast surgery, attendance of a plastic surgeon at the preoperative multidisciplinary teammeeting and a higher institutional rate of performingmastectomies. Next, the potential effect of the involved medical specialties was studied. Since the final decision to undergo/ perform IBR is made by patients and their surgical oncologists and plastic surgeons, personal opinions and attitudes of surgical oncologists and reconstructive plastic surgeons towards the decision to undergo IBR were studied. These professional opinions may vary or even differ and therefore questionnaires were sent to the clinicians in a nationwide survey ( Chapter 6 ). Plastic surgeons more frequently 9