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
Purpose: The recently developed fibroblast activation protein inhibitor (FAPI) tracer for PET/CT, binding tumour-stromal cancer-associated fibroblasts, is a promising tool for detection of positive... Show morePurpose: The recently developed fibroblast activation protein inhibitor (FAPI) tracer for PET/CT, binding tumour-stromal cancer-associated fibroblasts, is a promising tool for detection of positive lymph nodes. This study provides an overview of features, including sizes and tumour-stromal content, of lymph nodes and their respective lymph node metastases (LNM) in colorectal cancer (CRC), since literature lacks on whether LNMs contain sufficient stroma to potentially allow FAPI-based tumour detection. Methods: Haematoxylin and eosin-stained tissue slides from 73 stage III colon cancer patients were included. Diameters and areas of all lymph nodes and their LNMs were assessed, the amount of stroma by measuring the stromal compartment area, the conventional and total tumour-stroma ratios (TSR-c and TSR-t, respectively), as well as correlations between these parameters. Also, subgroup analysis using a minimal diameter cut off of 5.0 mm was performed. Results: In total, 126 lymph nodes were analysed. Although positive correlations were observed between node and LNM for diameter and area (r = 0.852, p < 0.001 and r = 0.960, p < 0.001, respectively), and also between the LNM stromal compartment area and nodal diameter (r = 0.612, p < 0.001), nodal area (r = 0.747, p < 0.001) and LNM area (r = 0.746, p < 0.001), novel insight was that nearly all (98%) LNMs contained stroma, with median TSR-c scores of 35% (IQR 20-60%) and TSR-t of 20% (IQR 10-30%). Moreover, a total of 32 (25%) positive lymph nodes had a diameter of < 5.0 mm. Conclusion: In LNMs, stroma is abundantly present, independent of size, suggesting a role for FAPI PET/CT in improved lymph node detection in CRC. Show less
Ren, J.; Smid, M.; Iaria, J.; Salvatori, D.C.F.; Dam, H. van; Zhu, H.J.; ... ; Dijke, P. ten 2019
In dit proefschrift worden studies besproken naar de rol van de TGF-β signaleringsroute in de tumor micro-omgeving in colorectaal kanker. Deze studies hebben zich voornamelijk gefocust op de rol... Show moreIn dit proefschrift worden studies besproken naar de rol van de TGF-β signaleringsroute in de tumor micro-omgeving in colorectaal kanker. Deze studies hebben zich voornamelijk gefocust op de rol van kanker-geassocieerde fibroblasten (CAFs) in kanker. Wij hebben aangetoond dat een co-receptor voor TGF-β, endoglin, een grote rol speelt in het CAF-gemedieerd uitzaaien van darmkanker en dat de expressie van endoglin op CAFs een prognostische marker is voor metastase-vrije overleving in vroeg stadium darmkankerpatienten. Daarnaast werd een nieuwe muizenstam ontwikkeld om specifiek op fibroblasten endoglin uit te schakelen, zodat de rol hiervan in het ontstaan van darmkanker bestudeerd kon worden in een chemisch geinduceerd model voor darmkanker. Samengevat laten de studies in dit proefschrift zien dat endoglin expressie op CAFs een belangrijke rol speelt in het metastaseren van colorectaalkanker en opent het deuren naar therapeutische toepassingen. Show less
