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
There is a pending need for prognostic and predictive biomarkers in the treatment of patients with colorectal cancer.This thesis describes the prognostic and predictive application of the tumor... Show moreThere is a pending need for prognostic and predictive biomarkers in the treatment of patients with colorectal cancer.This thesis describes the prognostic and predictive application of the tumor-stroma ratio (TSR) in colorectal cancer, focusing on expanding current clinical-pathological standards and combining TSR with other diagnostic parameters. The TSR is a microscopy scoring method performed on hematoxylin-eosin stained tissue slides used for routine pathology assessment, and has proven to be a robust prognostic maker. Here, we investigate whether the TSR also exhibits predictive value with regard to adjuvant targeted therapy in stage II and III colon cancer. Moreover, exploring the value of collagen fiber organization in the intratumoral stroma, as well as combining this parameter with the TSR. Finally, expanding the application of the TSR with radiological diagnostics in rectal cancer. Assessing is there is a correlation between TSR and apparent diffusion coefficient values obtained from diagnostically performed MRI-DWI scans, in order to determine if there is potential with regards to neoadjuvant treatment choices or patient follow-up. Show less
