Objective: This study evaluated the correlation between intratumoural stmma proportion, expressed as tumour-stroma ratio (TSR), and apparent diffusion coefficient (ADC) values in patients with... Show moreObjective: This study evaluated the correlation between intratumoural stmma proportion, expressed as tumour-stroma ratio (TSR), and apparent diffusion coefficient (ADC) values in patients with rectal cancer.Methods: This multicentre retrospective study included all consecutive patients with rectal cancer, diagnostically confirmed by biopsy and MRI. The training cohort (LUMC, Netherlands) included 33 patients and the validation cohort (VHIO, Spain) 69 patients. Two observers measured the mean and minimum ADCs based on single-slice and whole-volume segmentations. The TSR was determined on diagnostic haematoxylin & eosin stained slides of rectal tumour biopsies. The correlation between TSR and ADC was assessed by Spearman correlation (r(s)).Results: The ADC values between stroma-low and stroma-high tumours were not significantly different. Intraclass correlation (ICC) demonstrated a good level of agreement for the ADC measurements, ranging from 0.84-0.86 for single slice and 0.86-0.90 for the whole-volume protocol. No correlation was observed between the TSR and ADC values, with ADC(mean), r(s) = -0.162 (p= 0.38) and ADC(m)(in), r(s) = 0.041 (p= 0.82) for the single-slice and r(s) = -0.108 (p= 0.55) and r(s) = 0.019 (p= 0.92) for the whole-volume measurements in the training cohort, respectively. Results from the validation cohort were consistent; ADC(mean )r(s) = -0.022 (p= 0.86) and ADC(min), r(s) = 0.049 (p= 0.69) for the single-slice and r(s) = -0.064 (p= 0.59) and r(s) = -0.063 (p= 0.61) for the whole-volume measurements.Conclusions: Reproducibility of ADC values is good. Despite positive reports on the correlation between TSR and ADC values in other tumours, this could not be confirmed for rectal cancer. Show less
It has become clear that carcinogenesis goes beyond tumor cell biology. Cancer research has acknowledged the importance of biological functions of the tumor-microenvironment, wherein not only... Show moreIt has become clear that carcinogenesis goes beyond tumor cell biology. Cancer research has acknowledged the importance of biological functions of the tumor-microenvironment, wherein not only cellular components seem to hold valuable information but also structural components like collagen fibers. Several studies have focused on the significance of stromal collagen fiber organization and reported on its role in cancer progression, invasiveness and treatment response. In this review, we discuss the different imaging methods for stromal collagen organization, followed by an in-depth discussion of current literature on in-vitro and animal experiments and human studies, highlighting its importance with respect to cancer progression, prognosis and prediction. We can conclude that collagen organization contains valuable information with regard to metastatic potential and clinical outcomes in cancer. However, the significance of an aligned versus disorganized collagen morphology differs between cancer types, implying more research is necessary before steps towards clinical implementation can be made. Show less
It has become clear that carcinogenesis goes beyond tumor cell biology. Cancer research has acknowledged the importance of biological functions of the tumor-microenvironment, wherein not only... Show moreIt has become clear that carcinogenesis goes beyond tumor cell biology. Cancer research has acknowledged the importance of biological functions of the tumor-microenvironment, wherein not only cellular components seem to hold valuable information but also structural components like collagen fibers. Several studies have focused on the significance of stromal collagen fiber organization and reported on its role in cancer progression, invasiveness and treatment response. In this review, we discuss the different imaging methods for stromal collagen organization, followed by an in-depth discussion of current literature on in-vitro and animal experiments and human studies, highlighting its importance with respect to cancer progression, prognosis and prediction. We can conclude that collagen organization contains valuable information with regard to metastatic potential and clinical outcomes in cancer. However, the significance of an aligned versus disorganized collagen morphology differs between cancer types, implying more research is necessary before steps towards clinical implementation can be made. Show less
CDKN2A-p16-Leiden mutation carriers have a 20% to 25% risk of developing pancreatic ductal adenocarcinoma (PDAC). Better understanding of the natural course of PDAC might allow the surveillance... Show moreCDKN2A-p16-Leiden mutation carriers have a 20% to 25% risk of developing pancreatic ductal adenocarcinoma (PDAC). Better understanding of the natural course of PDAC might allow the surveillance protocol to be improved. The aims of the study were to evaluate the role of cystic precursor lesions in the development of PDAC and to assess the growth rate. In 2000, a surveillance program was initiated, consisting of annual MRI in carriers of a CDKN2A-p16-Leiden mutation. The study cohort induded 204 (42% male) patients. Cystic precursor lesions were found in 52 (25%) of 204 mutation carriers. Five (9.7%) of 52 mutation carriers with cystic lesions and 8 (7.0%) of 114 mutation carriers without cystic lesions developed PDAC (P = 0.56). Three of 6 patients with a cystic lesion of >= 10 mm developed PDAC. The median size of all incident PDAC detected between 9 and 12 months since the previous normal MRI was 15 mm, suggesting an annual growth rate of about 15 mm/year. In conclusion, our findings show that patients with and without a cystic lesions have a similar risk of PDAC. However, cystic precursor lesions between 10 and 20 mm increase the risk of PDAC substantially. In view of the large size of the screen-detected tumors, a shorter interval of screening might be recommended for all patients. (C) 2018 AACR. Show less
On-tissue digestion matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) can be used to record spatially correlated molecular information from formalin-fixed, paraffin... Show moreOn-tissue digestion matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) can be used to record spatially correlated molecular information from formalin-fixed, paraffin-embedded (FFPE) tissue sections. In this work, we present the in situ multimodal analysis of N-linked glycans and proteins from the same FFPE tissue section. The robustness and applicability of the method are demonstrated for several tumors, including epithelial and mesenchymal tumor types. Major analytical aspects, such as lateral diffusion of the analyte molecules and differences in measurement sensitivity due to the additional sample preparation methods, have been investigated for both N-glycans and proteolytic peptides. By combining the MSI approach with extract analysis, we were also able to assess which mass spectral peaks generated by MALDI-MSI could be assigned to unique N-glycan and peptide identities. Show less
Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging is a rapidly evolving field in which mass spectrometry techniques are applied directly on tissues to characterize the... Show moreMatrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging is a rapidly evolving field in which mass spectrometry techniques are applied directly on tissues to characterize the spatial distribution of various molecules such as lipids, protein/peptides, and recently also N-glycans. Glycans are involved in many biological processes and several glycan changes have been associated with different kinds of cancer, making them an interesting target group to study. An important analytical challenge for the study of glycans by MALDI mass spectrometry is the labile character of sialic acid groups which are prone to in-source/postsource decay, thereby biasing the recorded glycan profile. We therefore developed a linkage-specific sialic acid derivatization by dimethylamidation and subsequent amidation and transferred this onto formalin-fixed paraffin-embedded (FFPE) tissues for MALDI imaging of N-glycans. Our results show (i) the successful stabilization of sialic acids in a linkage specific manner, thereby not only increasing the detection range, but also adding biological meaning, (ii) that no noticeable lateral diffusion is induced during to sample preparation, (iii) the potential of mass spectrometry imaging to spatially characterize the N-glycan expression within heterogeneous tissues. Show less
BACKGROUND & AIMS: Surveillance of high-risk groups for pancreatic cancer might increase early detection and treatment outcomes. Individuals with germline mutations in p16-Leiden have a... Show moreBACKGROUND & AIMS: Surveillance of high-risk groups for pancreatic cancer might increase early detection and treatment outcomes. Individuals with germline mutations in p16-Leiden have a lifetime risk of 15% to 20% of developing pancreatic cancer. We assessed the feasibility of detecting pancreatic cancer at an early stage and investigated the outcomes of patients with neoplastic lesions. METHODS: Individuals with germline mutations in p16-Leiden (N = 79; 31 male; mean age, 56 years; range, 39-72 years) were offered annual surveillance by magnetic resonance imaging (MRI) and magnetic resonance cholangiopancreatography (MRCP). Those found to have neoplastic lesions were offered options for surgery or intensive follow-up. Individuals found to have possible neoplastic lesions were examined again by MRI/MRCP within 2 to 4 months. RESULTS: After a median follow-up period of 4 years (range, 0-10 years), pancreatic cancer was diagnosed in 7 patients (9%). The mean age at diagnosis was 59 years (range, 49-72 years). Three of the tumors were present at the first examination, and 4 were detected after a negative result in the initial examination. All 7 patients had a resectable lesion; 5 underwent surgery, 3 had an R0 resection, and 2 had lymph node metastases. Possible precursor lesions (ie, duct ectasias, based on MRCP) were found in 9 individuals (11%). CONCLUSIONS: MRI/MRCP detects small, solid pancreatic tumors and small duct ectasias. Although surveillance increases the rate of resectability, carriers of a p16-Leiden mutation develop agressive tumors. Show less
BACKGROUND: Large number of patients with colorectal liver metastasis show recurrent disease after curative surgical resection. Identification of these high-risk patients may guide therapeutic... Show moreBACKGROUND: Large number of patients with colorectal liver metastasis show recurrent disease after curative surgical resection. Identification of these high-risk patients may guide therapeutic strategies. The aim of this study was to evaluate whether the presence of disseminated tumor cells in bone marrow from patients undergoing surgical resection of colorectal liver metastases can predict clinical outcome. METHODS: Sixty patients with colorectal liver metastases were planned for a curative resection between 2001 and 2007. All patients underwent bone marrow aspiration before surgery. Detection of tumor cells was performed using immunocytochemical staining for cytokeratin (CK-ICC) combined with automated microscopy or indirectly using reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: Disseminated tumor cells were found in 15 of the 46 patients (33%) using CK-ICC and in 9 of 44 of the patients (20%) using RT-PCR. Patients with negative results for RT-PCR had a significant better disease-free survival after resection of their liver metastases (p = 0.02). This group also showed significant better overall survival (p = 0.002). CK-ICC did not predict a worse clinical outcome. CONCLUSIONS: The presence of disseminated tumor cells in bone marrow detected using RT-PCR did predict a worse clinical outcome. The presence of cells detected with CK-ICC did not correlate with poor prognosis. Show less
Up to 30% of stage II patients with curatively resected colorectal cancer (CRC) will develop disease recurrence. We evaluated whether examination of lymph nodes by multilevel sectioning and... Show moreUp to 30% of stage II patients with curatively resected colorectal cancer (CRC) will develop disease recurrence. We evaluated whether examination of lymph nodes by multilevel sectioning and immunohistochemical staining can improve prognostication. Lymph nodes (n = 780) from 36 CRC patients who had developed disease recurrence (cases) and 72 patients who showed no recurrence of disease for at least 5 years (controls) were analyzed. Sections of 4 levels at 200-mu m interval were immunohistochemically stained for cytokeratin expression. The first level was analyzed by conventional and automated microscopy, and the 3 following levels were analyzed by automated microscopy for the presence of tumor cells. Overall, cases showed more micrometastases (3 patients) than controls (1 patient). Analysis of a second level led to the additional detection of 1 patient with micrometastases (case) and 1 patient with macrometastasis (case). Examining more levels only led to additional isolated tumor cells, which were equally divided between cases and controls. Likewise, automated microscopy resulted only in detection of additional isolated tumor cells when compared with conventional microscopy. In multivariate analysis, micrometastases [odds ratio (OR) 26.3, 95% confidence interval (CI) 1.9-364.8, p = 0.015], T4 stage (OR 4.8, 95% CI 1.4-16.7, p = 0.013) and number of lymph nodes (OR 0.9, 95% CI 0.8-1.0, p = 0.028) were independent predictors for disease recurrence. Lymph node analysis of 2 levels and immunohistochemical staining add to the detection of macrometastases and micrometastases in CRC. Micrometastases were found to be an independent predictor of disease recurrence. Isolated tumor cells were of no prognostic significance. Show less
