The studies in this thesis contribute to more accurate risk assessment and prognosis prediction for DCIS and to better response evaluation of IBC treatment.For the Ductal Carcinoma In Situ (DCIS)... Show moreThe studies in this thesis contribute to more accurate risk assessment and prognosis prediction for DCIS and to better response evaluation of IBC treatment.For the Ductal Carcinoma In Situ (DCIS) studies, unbiased cohorts were used within the international Grand Challenge PRECISION consortium, funded by Cancer Research UK and KWF Dutch Cancer Society. DCIS is graded as low-, intermediate-, or high-grade depending on how abnormal the DCIS-cells look like. However, we showed that pathologists often disagree on grade. To overcome this limitation, we found that almost all DCIS scored as non-high-grade by the majority of pathologists express the estrogen receptor (ER) and are negative for the growth factor receptor HER2, whereas high-grade DCIS is mixed in expression for ER and HER2. We also provided insights in the recurrence risks of DCIS after treatment. See also https://cancergrandchallenges.org/teams/precision.The studies on Invasive Breast Cancer (IBC) were performed on a hospital-based cohort. We found for example substantial variation in tumour response evaluation for HER2-positive IBC after pre-operative chemotherapy due to different guidelines used. For accurate outcome analysis, reducing such variation is mandatory. Therefore, we are working on reaching international consensus of response evaluation. Show less
This thesis consists of two parts. In part I, we have demonstrated that preoperatively administrated systemic (neoadjuvant) therapy is a feasible treatment strategy in early stage breast cancer to... Show moreThis thesis consists of two parts. In part I, we have demonstrated that preoperatively administrated systemic (neoadjuvant) therapy is a feasible treatment strategy in early stage breast cancer to achieve improved surgical options and to assess tumor response. We also demonstrated that overexpression of the breast cancer stem cell marker aldehyde dehydrogenase-1 in early stage breast cancer patients is inversely associated with age and is of prognostic importance. In part II, we have demonstrated proof-of-principle of intraoperative tumor detection and image-guided tumor resection by using the novel technique of near-infrared fluorescence imaging. We have performed two clinical trials to optimize the use of indocyanine green as a near-infrared fluorescence lymphatic tracer for the sentinel lymph node procedure in breast cancer patients. Show less
