Oncology Commons^™

Design Of Novel Sensors And Instruments For Minimally Invasive Lung Tumour Localization Via Palpation, Anish Srinivasan Naidu

Electronic Thesis and Dissertation Repository

Minimally Invasive Thoracoscopic Surgery (MITS) has become the treatment of choice for lung cancer. However, MITS prevents the surgeons from using manual palpation, thereby often making it challenging to reliably locate the tumours for resection. This thesis presents the design, analysis and validation of novel tactile sensors, a novel miniature force sensor, a robotic instrument, and a wireless hand-held instrument to address this limitation. The low-cost, disposable tactile sensors have been shown to easily detect a 5 mm tumour located 10 mm deep in soft tissue. The force sensor can measure six degrees of freedom forces and torques with temperature …

Kiss1r Signaling Promotes Breast Cancer Drug Resistance, Alexandra J. Blake

Electronic Thesis and Dissertation Repository

Kisspeptins signal via the G-protein coupled receptor, KISS1R, and act as metastasis suppressors in numerous cancers. In estrogen receptor (ERα)-negative breast cancer cells, however, KISS1R signaling promotes cell invasion by activating the epidermal growth factor receptor (EGFR). Unfortunately, clinical success of anti-EGFR therapeutics has been limited, as patients often develop drug resistance. Recently, another receptor tyrosine kinase, AXL, has been shown to promote breast cancer drug resistance. We hypothesize that KISS1R promotes EGFR expression and induces breast cancer drug resistance. We demonstrated that KISS1R increases EGFR transcription, by increasing SP-1 binding to the EGFR promoter, as demonstrated by chromatin immunoprecipitation …

Investigating The Role Of Hydrogen Sulfide In The Survival, Growth And Angiogenic Potential Of Clear Cell Renal Cell Carcinoma Cell Lines And Xenografts, Eric Sonke

Electronic Thesis and Dissertation Repository

Clear cell renal cell carcinoma (ccRCC) is characterized by Von Hippel-Lindau (VHL)-deficiency, resulting in pseudohypoxic, angiogenic and glycolytic tumours. Hydrogen sulfide (H₂S) is an endogenously-produced gasotransmitter that accumulates under hypoxia and has been shown to be pro-angiogenic and cytoprotective in cancer. It was hypothesized that H₂S levels are elevated in VHL-deficient ccRCC, contributing to survival, metabolism, and angiogenesis. Using H₂S-specific probes, it was found that H₂S levels were higher in VHL-deficient ccRCC cell lines compared to cells with wild-type VHL. Inhibition of H₂S-producing enzymes could reduce the proliferation, metabolism …

Overall Survival And Biochemical Failure-Free Survival Comparison Of Brachytherapy Treatment Options Versus External Beam Radiation Therapy For Both Low And Intermediate-Risk Prostate Cancer: A Propensity-Score Matched Analysis, Graham D. Smith

Electronic Thesis and Dissertation Repository

Purpose: This study compares overall survival (OS) and biochemical failure-free survival (bFFS) in low- and intermediate-risk prostate cancer patients that received brachytherapy [low-dose-rate brachytherapy (LDR-BT) or high-dose-rate brachytherapy with external beam radiation therapy (HDR-BT+EBRT)] versus external beam radiation therapy (EBRT) alone.

Materials/Methods: Patient data was obtained from the ProCaRS database, which contains 7974 prostate cancer patients treated at four Canadian institutions. Propensity score (PS) matching was used to generate matched cohorts with balanced baseline prognostic factors.

Results/Conclusions: Final PS matches included two 1:1 intermediate-risk patient matches, LDR-BT vs. EBRT (total n = 254) and HDR-BT+EBRT vs. EBRT (total n=388), and …

Mri Relaxation Rates: A Quantitative Approach To Track Tumour Cells Expressing Maga, Anindita Sengupta

Electronic Thesis and Dissertation Repository

Using magnetic resonance imaging, relaxation rate measurements were

performed in cancer cells overexpressing a magnetotactic bacterial gene, MagA.

Measurements of magnetic resonance relaxation rates in this expression

system is important for optimizing cell detection and specificity, for developing

quantification methods, and for refinement of gene-based iron contrast using

magnetosome associated genes. We measured the total transverse

relaxation rate (R2^*), its irreversible and reversible components (R2 and R2^′,

respectively) and the longitudinal relaxation rate (R1) in MDA-MB-435 tumor cells.

Clonal lines overexpressing MagA were cultured in the presence and absence of

iron supplementation, and mounted in a …

Multiparametric Imaging And Mr Image Texture Analysis In Brain Tumors, Harish A. Sharma

Electronic Thesis and Dissertation Repository

Discrimination of tumor from radiation injured (RI) tissues and differentiation of tumor types using noninvasive imaging is essential for guiding surgical and radiotherapy treatments are some of the challenges that clinicians face in the course of treatment of brain tumors. The first objective in this thesis was to develop a method to discriminate between glioblastoma tumor recurrences and radiation injury using multiparametric characterization of the tissue incorporating conventional magnetic resonance imaging signal intensities and diffusion tensor imaging parameters. Our results show significant correlations in the RI that was missing in the tumor regions. These correlations may aid in differentiating between …

Measuring The Sixth Vital Sign: A Descriptive Analysis Of Distress In Individuals With Head And Neck Cancer And Their Caregivers, Catherine C. Bornbaum

Electronic Thesis and Dissertation Repository

Introduction: Distress has become so problematic in oncology that it has been recognized as the “sixth vital sign” implying that distress monitoring should occur as routinely as the monitoring of one’s temperature or blood pressure. The research reported herein investigated the impact of head and neck cancer on levels of distress, commonly reported problems, and perceptions of quality of life in individuals with head and neck cancer and their caregivers.

Method: Two distinct studies were conducted; the first explored the patient experience of distress and quality of life while the second assessed the caregiver experience of these same constructs. A …

The Impact Of Lateral Electron Disequilibrium On Stereotactic Body Radiation Therapy Of Lung Cancer, Brandon Disher

Electronic Thesis and Dissertation Repository

Stereotactic Body Radiation Therapy (SBRT) is an effective treatment option for patients with inoperable early-stage lung cancer. SBRT uses online image-guidance technology [e.g. cone-beam CT (CBCT)] to focus small-fields of high energy x-rays onto a tumour to deliver ablative levels of radiation dose (e.g. 54 Gy) in a few treatment fractions (e.g. 3). For the combination of these treatment parameters and a low density lung, lateral electron disequilibrium (LED) can potentially occur, reducing lung and tumour doses. The goal of this thesis was to determine the impact of LED on stereotactic body radiation therapy for lung cancer.

The effect of …

Targeted Sirna Delivery Methods For Rnai-Based Therapies, Di Chen

Electronic Thesis and Dissertation Repository

RNAi has great potential in future therapeutics as it has the ability to regulating many disease-related genes. However, many barriers prevent practical applications. To overcome the barriers, the specific targeting, efficient delivery system, the validated gene and the potent siRNA sequence are all vital important. The studies throughout this thesis have been focued on examining the validation of three RNAi therapies for two different disease models: allergic contact dermatitis and melanoma. For allergic contact dermatitis, I developed and tested a novel topical delivery system for siRNAs targeting TNFα (siTNFα) and MyD88 siRNA (siMyD88). While siRNAs applied without the transdermal enhancer …

The Impact Of The Neuropeptide Y System On The Progression Of Breast Cancer, Philip J. Medeiros

Electronic Thesis and Dissertation Repository

Chronic stress is associated with elevated levels of sympathetic neurotransmitter release and immunosuppression. A growing body of evidence suggests that stress-related factors may contribute to the initiation, development and progression of breast cancer. Neuropeptide Y (NPY) has recently been determined as such a factor, however few investigations have addressed the functional effects of NPY on breast cells and tumors. Thus, the overall objective of this thesis was to elucidate the mechanisms by which NPY may contribute to the disease. Using the 4T1 murine breast cancer model, we began by first characterizing NPY receptor expression in cancer cells and tumors. Y1R, …

Targeted Intracellular Therapeutic Delivery Using Liposomes Formulated With Multifunctional Fast Proteins, Rae L. Nesbitt

Electronic Thesis and Dissertation Repository

Prostate cancer is the most common malignancy in North American men and there is no treatment currently available which offers a clear survival advantage to patients with prostate cancer. We studied liposomes formulated with the fusion-associated small transmembrane (FAST) protein, p14. In this study, we hypothesized that therapeutics delivered in molecular targeted fusogenic liposomes will increase intracellular delivery and specificity for prostate cancer. We demonstrated that liposomes formulated with p14-bombesin significantly increased the delivery of fluorescein isothiocyanate (FITC) into human prostate cancer (PC-3) cells compared to either standard liposomes or non-targeted fusogenic liposomes. Delivery of FITC to benign prostate hyperplasia …

Strategies For Reducing The Impact Of Tumour Motion During Helical Tomotherapy, Bryan Kim

Electronic Thesis and Dissertation Repository

Tumour motion presents a significant limitation for effective radiotherapy of lung cancer, and more specifically for helical tomotherapy. The simultaneous and continuous movements of tomotherapy subsystems (gantry, couch, and binary multi-leaf collimator) can lead to inaccurate dose delivery, when combined with tumour motion. In this thesis, we have investigated the impact of tumour motion and strategies to reduce the resulting dose discrepancies for helical tomotherapy, through computer simulations and film measurements performed in a dynamic body phantom. Three distinctively different types of dose discrepancies have been isolated: dose rounding, dose rippling, and the intensity-modulated radiation therapy (IMRT) asynchronization effect. Each …

Metastatic Disease: Interactions Between Tumor Cells And Host Environment During Cancer Cell Spread, Jennifer M. Maclean

Electronic Thesis and Dissertation Repository

Tumor and metastasis formation are not cell autonomous phenomena, but rather an evolution of disease within and responding to the host environment. Metastatic spread from a primary tumor occurs as a result of a complex interplay between tumor cells and the host, wherein tumor cells must escape the primary tumor, enter the host vasculature, travel to and arrest in a distant tissue and survive and grow in that new organ. It is known that cells that progress through these stages must both escape and exploit host systems, yet the mechanisms used are not fully understood. Therefore, the goal of this …

From Isolated Tumour Cells To Overt Lymph Node Metastases: Biological And Imaging Studies On The Development Of Experimental Lymph Node Metastases, Michael M. Lizardo

Electronic Thesis and Dissertation Repository

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 …