With the introduction of population-based screening, early-stage colorectal cancers (T1CRCs) are increasingly detected. The treatment of patients with T1CRC is complex, as these tumors have... Show moreWith the introduction of population-based screening, early-stage colorectal cancers (T1CRCs) are increasingly detected. The treatment of patients with T1CRC is complex, as these tumors have metastatic potential despite their early stage. As a result, local organ-sparing endoscopic tumor resection is not always sufficient, thereby giving rise to various challenges throughout the entire treatment process.The overarching goal of this thesis is to improve clinical care for T1CRC patients. Part 1 is centered around the biology and translational potential of the tumor microenvironment, and in particular cancer-associated fibroblasts (CAFs), in T1CRC. The studies in this part show that CAFs in T1CRCs exhibit T1 stage-specific phenotypic traits and can promote cancer cell invasion in T1CRC through diverse mechanisms. These findings provide promising leads for developing better predictors of metastasis, which can be used to determine which T1CRC patients will (not) benefit from major bowel surgery.Part 2 focuses on the clinical aspects of T1CRC treatment. The studies in this part show that local endoscopic tumor resection has become a mature alternative to surgery, from both the patient’s and oncological perspective. However, further optimizations of local resection techniques and surveillance thereafter are needed to increase the use of organ-sparing treatment for T1CRC patients. Show less
The goal of this thesis was to gain insight into the interactions between cancer-associated fibroblasts and cells of the immune system, together comprising the field of stromal immunobiology, in... Show moreThe goal of this thesis was to gain insight into the interactions between cancer-associated fibroblasts and cells of the immune system, together comprising the field of stromal immunobiology, in colorectal cancer and pancreatic ductal adenocarcinoma. Show less