This thesis assessed the quality of breast cancer care on different level by analyzing data from a tertiary cancer center and multiple nationwide databases.In order to do so, we first provided... Show moreThis thesis assessed the quality of breast cancer care on different level by analyzing data from a tertiary cancer center and multiple nationwide databases.In order to do so, we first provided insight into breast cancer patients changing hospital and the medical impact of a second opinion. The results demonstrated that a hospital transfer after diagnosis is a delaying factor for primary treatment, specifically for those who undergo surgery. Furthermore, we assessed in a reproducible manner that second opinions can have a significant impact on diagnostics and primary treatment strategies. In the second part, we assess the delaying impact of postmastectomy immediate breast reconstruction on the continuity of the adjuvant chemotherapy pathway. This part furthermore highlights the importance of timely initiation of adjuvant chemotherapy on survival in patients diagnosed with triple-negative breast cancer. Finally, we evaluate the use of breast‐contour preservation and safety of oncoplastic strategies on an (inter)national level. We demonstrate that a breast reconstruction using a direct‐to‐implant compared to a two‐stage technique is associated with a lower unplanned revision. Although the total breast‐contour preservation rate in the Netherlands is similar to Denmark, different strategies are used. Furthermore, oncoplastic techniques seem a safe option regarding re‐excision and conversion to mastectomy. Hereby, the findings in this thesis may contribute to different dimensions of the quality of breast cancer care. Show less