Annelotte van Bommel

18 ABSTRACT Background: In 2011, the NABON Breast Cancer Audit (NBCA) was instituted as a nation-wide audit to address quality of breast cancer care and guideline adherence in the Netherlands. The development of the NBCA and the results of 4 years of auditing are described. Methods: Clinical and pathological characteristics of patients diagnosed with invasive breast cancer or in situ carcinoma (DCIS) and information regarding diagnosis and treatment are collected in all hospitals (n=92) in the Netherlands. Thirty-two quality indicators measuring care structure, processes and outcomes were evaluated over time and compared between hospitals. Results: TheNBCA contains data of 56,927 patients (7,649DCIS and 49,073 invasive cancers). Patients being discussed in pre- and post-operative multidisciplinary teammeetings improved (2011: 83% and 91%; 2014: 98% and 99%, respectively) over the years. Tumor margin positivity rates after breast conserving surgery for invasive cancer requiring re-operation were consistently low (~5%). Other indicators, for example, the use of anMRI-scan prior to surgery or immediate breast reconstruction following mastectomy showed considerable hospital variation. Conclusions: Results show an overall high quality of breast cancer care in all hospitals in the Netherlands. For most quality indicators improvement was seen over time, while some indicators showed yet unexplained variation.