CELLULAR MRI: TRACKING THE MIGRATION OF METASTATIC CANCER CELLS IN THE LYMPHATIC SYSTEM

The role of the lymphatics as a mode of tumor cell transport has been known for some time, and remains of critical importance since a majority of cancer deaths result from metastatic dissemination away from the primary tumor. In the studies performed in this thesis novel cellular MRI technology and a unique murine intranodal implantation model are used to track the movement of iron-labeled melanoma cells in vivo. With these methods we demonstrate, for the first time, that cellular MRI can be used to detect metastatic melanoma cells present at the implant site and in the draining lymph node and to track the growth of these cells into a metastatic tumor. The ability to track metastatic cancer cells in the lymphatic system in vivo may promote a better understanding of models of carcinogenesis and metastasis and in the future may help to improve on principles by which cancers are treated

CELLULAR MRI: TRACKING THE MIGRATION OF METASTATIC CANCER CELLS IN THE LYMPHATIC SYSTEM

The role of the lymphatics as a mode of tumor cell transport has been known for some time, and remains of critical importance since a majority of cancer deaths result from metastatic dissemination away from the primary tumor. In the studies performed in this thesis novel cellular MRI technology and a unique murine intranodal implantation model are used to track the movement of iron-labeled melanoma cells in vivo. With these methods we demonstrate, for the first time, that cellular MRI can be used to detect metastatic melanoma cells present at the implant site and in the draining lymph node and to track the growth of these cells into a metastatic tumor. The ability to track metastatic cancer cells in the lymphatic system in vivo may promote a better understanding of models of carcinogenesis and metastasis and in the future may help to improve on principles by which cancers are treated

From Isolated Tumour Cells to Overt Lymph Node Metastases: Biological and Imaging Studies on the Development of Experimental Lymph Node Metastases

Metastatic colonization and establishment of overt lymph node (LN) tumours indicates poor prognosis for cancer patients. However, the basic biology that influences the development of LN metastasis is poorly understood due to the lack of basic animal models. The following work provides a new lymph node experimental metastasis assay (LEMA) that permits the assessment of tumour cell fate after they arrest in draining LNs. In using this new model, we discovered that only 8% of the tumour cells that arrive in the LN are successful in forming overt tumours. This work also explored the use of imaging approaches to monitor the process on LN metastasis in mice. To study the in vivo growth of LN metastases, we used 3-dimensional high frequency ultrasound (HFUS). We observed that growth rates of LN tumours varied from mouse to mouse. Furthermore, HFUS allowed us to visualize small metastatic deposits and micrometastases and their growth over time. In order to provide some ground work for the development of magnetic resonance imaging (MRI) of lymph node metastases, we developed a gel phantom that simulated the metastatic colonization of LNs. By labeling cells with gadofluorine M (GdF, a positive contrast agent), we were able to demonstrate how MRI (3 Tesla) was able to quantitatively measure the abundance of GdF-labeled tumour cells. The research described herein will expedite future research by providing a new experimental lymph node metastasis assay and novel imaging techniques that will permit the study of metastasis development in the lymph node

Engineering Iron Oxide Nanoparticles for Clinical Settings

Iron oxide nanoparticles (IONPs) occupy a privileged position among magnetic nanomaterials with potential applications in medicine and biology. They have been widely used in preclinical experiments for imaging contrast enhancement, magnetic resonance, immunoassays, cell tracking, tissue repair, magnetic hyperthermia and drug delivery. Despite these promising results, their successful translation into a clinical setting is strongly dependent upon their physicochemical properties, toxicity and functionalization possibilities. Currently, IONPs-based medical applications are limited to the use of non-functionalized IONPs smaller than 100 nm, with overall narrow particle size distribution, so that the particles have uniform physical and chemical properties. However, the main entry of IONPs into the scene of medical application will surely arise from their functionalization possibilities that will provide them with the capacity to target specific cells within the body, and hence to play a role in the development of specific therapies. In this review, we offer an overview of their basic physicochemical design parameters, giving an account of the progress made in their functionalization and current clinical applications. We place special emphasis on past and present clinical trials

In Vivo PET Detection of Lung Micrometastasis in Mice by Targeting Endothelial VCAM-1 Using a Dual-Contrast PET/MRI Probe

Current clinical diagnostic imaging methods for lung metastases are sensitive only to large tumours (1–2 mm cross-sectional diameter), and early detection can dramatically improve treatment. We have previously demonstrated that an antibody-targeted MRI contrast agent based on microparticles of iron oxide (MPIO; 1 μm diameter) enables the imaging of endothelial vascular cell adhesion molecule-1 (VCAM-1). Using a mouse model of lung metastasis, upregulation of endothelial VCAM-1 expression was demonstrated in micrometastasis-associated vessels but not in normal lung tissue, and binding of VCAM-MPIO to these vessels was evident histologically. Owing to the lack of proton MRI signals in the lungs, we modified the VCAM-MPIO to include zirconium-89 (89Zr, t1/2 = 78.4 h) in order to allow the in vivo detection of lung metastases by positron emission tomography (PET). Using this new agent (89Zr-DFO-VCAM-MPIO), it was possible to detect the presence of micrometastases within the lung in vivo from ca. 140 μm in diameter. Histological analysis combined with autoradiography confirmed the specific binding of the agent to the VCAM-1 expressing vasculature at the sites of pulmonary micrometastases. By retaining the original VCAM-MPIO as the basis for this new molecular contrast agent, we have created a dual-modality (PET/MRI) agent for the concurrent detection of lung and brain micrometastases

In Vivo PET Detection of Lung Micrometastasis in Mice by Targeting Endothelial VCAM-1 Using a Dual-Contrast PET/MRI Probe

Current clinical diagnostic imaging methods for lung metastases are sensitive only to large tumours (1–2 mm cross-sectional diameter), and early detection can dramatically improve treatment. We have previously demonstrated that an antibody-targeted MRI contrast agent based on microparticles of iron oxide (MPIO; 1 μm diameter) enables the imaging of endothelial vascular cell adhesion molecule-1 (VCAM-1). Using a mouse model of lung metastasis, upregulation of endothelial VCAM-1 expression was demonstrated in micrometastasis-associated vessels but not in normal lung tissue, and binding of VCAM-MPIO to these vessels was evident histologically. Owing to the lack of proton MRI signals in the lungs, we modified the VCAM-MPIO to include zirconium-89 (89Zr, t1/2 = 78.4 h) in order to allow the in vivo detection of lung metastases by positron emission tomography (PET). Using this new agent (89Zr-DFO-VCAM-MPIO), it was possible to detect the presence of micrometastases within the lung in vivo from ca. 140 μm in diameter. Histological analysis combined with autoradiography confirmed the specific binding of the agent to the VCAM-1 expressing vasculature at the sites of pulmonary micrometastases. By retaining the original VCAM-MPIO as the basis for this new molecular contrast agent, we have created a dual-modality (PET/MRI) agent for the concurrent detection of lung and brain micrometastases

Diagnostic Significance of Exosomal miRNAs in the Plasma of Breast Cancer Patients

Poster Session AbstractsBackground and Aims: Emerging evidence that microRNAs (miRNAs) play an important role in cancer development has opened up new opportunities for cancer diagnosis. Recent studies demonstrated that released exosomes which contain a subset of both cellular mRNA and miRNA could be a useful source of biomarkers for cancer detection. Here, we aim to develop a novel biomarker for breast cancer diagnosis using exosomal miRNAs in plasma. Methods: We have developed a rapid and novel isolation protocol to enrich tumor-associated exosomes from plasma samples by capturing tumor specific surface markers containing exosomes. After enrichment, we performed miRNA profiling on four sample sets; (1) Ep-CAM marker enriched plasma exosomes of breast cancer patients; (2) breast tumors of the same patients; (3) adjacent non-cancerous tissues of the same patients; (4) Ep-CAM marker enriched plasma exosomes of normal control subjects. Profiling is performed using PCR-based array with human microRNA panels that contain more than 700 miRNAs. Results: Our profiling data showed that 15 miRNAs are concordantly up-regulated and 13 miRNAs are concordantly down-regulated in both plasma exosomes and corresponding tumors. These account for 25% (up-regulation) and 15% (down-regulation) of all miRNAs detectable in plasma exosomes. Our findings demonstrate that miRNA profile in EpCAM-enriched plasma exosomes from breast cancer patients exhibit certain similar pattern to that in the corresponding tumors. Based on our profiling results, plasma signatures that differentiated breast cancer from control are generated and some of the well-known breast cancer related miRNAs such as miR-10b, miR-21, miR-155 and miR-145 are included in our panel list. The putative miRNA biomarkers are validated on plasma samples from an independent cohort from more than 100 cancer patients. Further validation of the selected markers is likely to offer an accurate, noninvasive and specific diagnostic assay for breast cancer. Conclusions: These results suggest that exosomal miRNAs in plasma may be a novel biomarker for breast cancer diagnosis.link_to_OA_fulltex

Innovating surgery for oral squamous cell carcinoma with targeted fluorescent and magnetic tracers

Oral squamous cell carcinoma (OSCC) is characterised by its locally aggressive nature and its high propensity to metastasise to regional lymph nodes (LN)s. It is well-established that margin status and the presence of LN metastases are two of the most important factors affecting prognosis. While patient and tumour factors cannot be changed after presentation, margin control during primary tumour resection and staging of the clinically occult neck are two components of treatment that are within the control of the head and neck surgeon. Despite this, positive margin rates have not improved over the last three decades and staging of the clinically negative neck continues to rely on elective neck dissection (END), which results in overtreatment of up to 75% of patients. Molecular imaging, with tracers designed to target specific tissue and tumour ligands, is a growing field that has significant potential to improve outcomes for patients with OSCC. This thesis evaluates how two different tracer technologies could be used to aid either margin assessment during resection of the primary tumour, and/or staging of the clinically negative neck with sentinel lymph node biopsy (SLNB). The tracers studied within this thesis are Panitumumab-IRDye800CW, an EGFR-targeting fluorophore used for fluorescence molecular imaging, and FerroTrace, a superparamagnetic iron oxide nanoparticle (SPION) that has been engineered with mannose end targets for macrophage-specific binding to aid SLNB.Thesis (Ph.D.) -- University of Adelaide, Adelaide Medical School, 202

Use of neoadjuvant chemotherapy in locally advanced breast cancer in the Netherlands

Use of neoadjuvant chemotherapy in locally advanced breast cancer in the Netherlands P.E.R. Spronk1, A.C.M. Van Bommel1, S. Siesling2,3, M.J.T. Baas- Vrancken Peeters4, C.H. Smorenburg5. 1Leiden University Medical Centre, Surgery, Leiden, Netherlands; 2Comprehensive Cancer Centre the Netherlands IKNL, Epidemiology, Utrecht, Netherlands; 3University of Twente, MIRA Biomedical science and Technical Medicine, Twente, Netherlands; 4Netherlands Cancer Institute/Antoni van Leeuwenhoek, Surgery, Amsterdam, Netherlands; 5Netherlands Cancer Institute/Antoni van Leeuwenhoek, Medical Oncology, Amsterdam, Netherlands Background: Neoadjuvant chemotherapy (NAC) is the treatment of choice for patients with locally advanced breast cancer (LABC). The aim of this study is to examine the use of NAC for LABC in all Dutch hospitals participating in breast cancer care and to assess what patient, tumour and hospital characteristics influence its use. Material and Methods: Data were derived from the national multidisciplinary NABON Breast Cancer Audit (NBCA), regarding all women aged >18 years and newly diagnosed with LABC from January 2011 to September 2013. Multivariable logistic regression was used to assess the association between the use of NAC and patient, tumour and hospital related factors. Results: Of 1419 woman diagnosed with LABC, 70% were treated with NAC. This percentage varied from 12.5% to 90% between hospitals and did not increase over time. Factors associated with the use of NAC included young age, large tumour size, more advanced nodal disease and triple negative or hormone-receptor negative tumours. Also patients treated in hospitals with a multidisciplinary preoperative work-up and participation in neoadjuvant studies were more likely to receive NAC. However, considerable variation between hospitals remained after casemix correction. Table 1. Multivariable odds ratios (ORs) for receipt of NAC among 1419 stage III patients 2011 through 2013 OR 95% CI P-value Age 0.000 5 cm 5.68 2.34−13.79 Clinical nodal status 0.000 cNx/N0 ref. cN1 1.32 0.86−2.04 cN2 2.93 1.18−7.29 cN3 10.28 4.18−25.25 Receptor status 0.000 Triple negative 2.35 1.40−3.93 HR−, Her2+ 3.37 1.67−6.78 HR+, Her2+ 0.91 0.51−1.60 HR+, Her2− ref. Type of surgery 0.026 Breast conservation therapy 2.05 1.09−3.84 Mastectomy ref. Multidisciplinary team 0.021 Yes 1.98 1.11−3.53 No ref. Type of hospital 0.569 General 1.20 0.73−1.98 Top clinical ref. Academic 1.50 0.64−3.47 Hospital surgical volume 0.729 200 1.27 0.70−2.31 Study participation 0.005 Yes 1.80 1.20−2.70 No ref. Conclusions: There is considerable variation in the use of NAC for LABC in the Netherlands. Although various patient, tumor and institutional factors are associated with the use of NAC in LABC, these can only explain part of the observed variation in treatment patterns between hospitals