Medicine and Health Sciences Commons^™

About Dying And Death: Thanatology's Place In Medical Curriculum, Jill Dombroski

Electronic Thesis and Dissertation Repository

This study explored how healthcare providers engage in advance care planning and end-of-life care conversations. The research explored what shapes their understanding and the extent to which concepts from thanatology they intuitively bring in, explicitly bring in, and maybe fail to recognize. To achieve this, constructivist grounded theory (CGT) methodology guided the design, data collection, analysis, and interpretation of the findings, which allowed for iteration across interviews and analysis with existing theories and data in the literature. The CGT design encouraged further engagement with the literature in an ongoing iterative fashion as well as with the analysis of the data. …

Sarcopenia In Head And Neck Cancer: A Prognostic Analysis, Nedeljko Jovanovic

Electronic Thesis and Dissertation Repository

Introduction: In head and neck cancer (HNC), loss of skeletal muscle mass (SMM), or sarcopenia, is a strong prognostic factor for outcomes. However, inconsistencies in its assessment limit our understanding of the relationship between sarcopenia and nutrition-related outcomes. This project evaluated the significance of sarcopenia as described in the literature and as demonstrated in a cohort of HNC patients.

Methods: A scoping review was first conducted followed by a retrospective cohort study with data collected from 194 oropharyngeal carcinoma patients treated with definitive radiation/chemoradiation. Sarcopenia was assessed from computed tomography (CT) imaging at the third cervical vertebra (C3) and the …

The Molecular Landscape Of Early-Stage Breast Cancer With Lymph Node Metastasis, Farhad Ghasemi

Electronic Thesis and Dissertation Repository

Axillary lymph nodes (ALNs) are the primary site of metastasis in breast cancer, and their involvement has implications in disease staging, prognostication, and treatment decisions. A non-invasive modality of assessing the risk of ALN metastasis can improve care in patients with early-stage breast cancer by omitting the morbidity and costs associated with axillary surgery.

This thesis explores the molecular landscape of early-stage breast cancers with ALN metastasis and shows the potential of tumour molecular signatures in predicting ALN involvement. After a systematic review of the literature, we use data from The Cancer Genome Atlas (TCGA) to develop molecular signatures correlated …

Anticancer Effects And Mechanisms Of Cfi-400945 And Radiation In Breast Cancer, Sierra M. Pellizzari

Electronic Thesis and Dissertation Repository

Breast cancer is a leading cause of death in women and development of new treatments is essential. Polo-like Kinase 4 (PLK4) controls centriole duplication and its inhibition by CFI-400945 induces genomic instability and aneuploidy. Radiation therapy (RT) also induces aneuploidy leading to cell death, although development of radioresistance is common. We hypothesized that CFI-400945 and RT act synergistically in breast cancer. Colony formation assays identified synergistic anticancer effects of CFI-400945 and RT, with combinatorial effects also observed for RT with either siRNA inhibition of PLK4 or with the PLK4 inhibitor Centrinone B. This suggests that the antiproliferative effect of these …

Understanding The Role Of Rhamm In Tumor Load– Mediated Tumor Invasiveness Of Triple Negative Breast Cancer, Ashwin Sritharan, Britney Messam

Undergraduate Student Research Internships Conference

1.Compare the levels of proliferation between RHAMM+/+ and RHAMM -/- MDA-MB-231 spheroids as determined by ki67 and Caspase 3 signaling 2.Compare levels of RHAMM, CD44, Has2, and p-ERK activation between RHAMM+/+ and RHAMM -/- MDA-MB-231 spheroids

Characterizing Cancer Associated Fibroblasts From Pancreatic Ductal Adenocarcinoma Patient Samples, Rachel Lu

Undergraduate Student Research Internships Conference

No abstract provided.

Incidence Of Cancer And Stage At Diagnosis Among People With Recent-Onset Psychotic Disorders, Jared C. Wootten

Electronic Thesis and Dissertation Repository

Evidence on cancer incidence in people with psychotic disorders, compared to the general population, is equivocal, although those with psychotic disorders so have more advanced stage of cancer at the time of diagnosis. The objective of this thesis was to compare cancer incidence and stage at diagnosis for people with psychotic disorders, relative to the general population. Our systematic review did not observe a significant difference in overall cancer incidence among people diagnosed with psychotic disorders (RR = 1.08, 95% CI: 1.00 to 1.16), however people with psychotic disorders were more likely to be present with advanced stage cancer at …

Addressing Bias In Non-Experimental Studies Assessing Treatment Outcomes In Prostate Cancer, David E. Guy

Electronic Thesis and Dissertation Repository

We evaluated the ability of matching techniques to balance baseline characteristics between treatment groups using non-experimental data. We identified a set of balance diagnostics that assessed key differences in baseline covariates with potential for confounding. These diagnostics were used in a novel systematic approach to developing and evaluating models for use in propensity score matching that optimized balance and data retention. We then compared the performance of propensity score and coarsened exact matching strategies in optimizing balance and data retention, using non-experimental data from a pan-Canadian prostate cancer database. Both matching techniques balanced baseline covariates adequately and retained approximately 70% …

Differential Effects Of Kim-1 In Subcutaneous And Orthotopic Renca Models Of Kidney Cancer, Demitra M. Yotis Dy

Electronic Thesis and Dissertation Repository

Renal Cell Carcinoma (RCC) is the most common and fatal type of kidney cancer. Over 30% of patients that are diagnosed with RCC exhibit metastases. Almost 88% of patients with distant metastases succumb to the disease within 5 years of diagnosis. Kidney Injury Molecule-1 (KIM-1) is a cell surface glycoprotein that is not expressed in a healthy kidney but becomes highly expressed on proximal tubular epithelial cells (PTECs) following injury. Data from the Cancer Genome Atlas (TCGA) reveals that >90% of RCC tumours express KIM-1 mRNA and that higher expression levels correlate with increased overall survival rates of patients. The …

Functional Role Of Dream And Dyrk1a In High-Grade Serous Ovarian Cancer Cell Dormancy, Pirunthan Perampalam

Electronic Thesis and Dissertation Repository

High-grade serous ovarian cancer (HGSOC) is the most common form of ovarian cancer. The majority of women are disproportionately diagnosed at an advanced stage (stage III-IV) of the disease when tumours have progressed beyond the ovaries or fallopian tubes and into the peritoneal cavity. Survival rates at late-stage are as low as 25% and chemoresistant disease recurrence is common, affecting up to 90% of patients. Multicellular clusters called spheroids contribute to dormancy, chemoresistance, and metastases and are a major challenge to treatment of HGSOC. Spheroid cells undergo reversible quiescence to evade chemotherapy in a process mediated by the mammalian DREAM …

Pathway‐Extended Gene Expression Signatures Integrate Novel Biomarkers That Improve Predictions Of Patient Responses To Kinase Inhibitors, Ashis Bagchee‐Clark, Eliseos J. Mucaki, Tyson Whitehead, Peter Rogan

Biochemistry Publications

Cancer chemotherapy responses have been related to multiple pharmacogenetic biomarkers, often for the same drug. This study utilizes machine learning to derive multi‐gene expression signatures that predict individual patient responses to specific tyrosine kinase inhibitors, including erlotinib, gefitinib, sorafenib, sunitinib, lapatinib and imatinib. Support vector machine (SVM) learning was used to train mathematical models that distinguished sensitivity from resistance to these drugs using a novel systems biology‐based approach. This began with expression of genes previously implicated in specific drug responses, then expanded to evaluate genes whose products were related through biochemical pathways and interactions. Optimal pathway‐extended SVMs predicted responses in …

An Exploration Of Facial Skin Scarring, Its Impact And Contemporary Evaluation, Michael G. Brandt

Electronic Thesis and Dissertation Repository

Facial skin cancer secondary to surgical treatment may be distressing due to the malignancy itself and from the consequences of its treatment. A visible postsurgical scar is an obvious reminder of the condition. This investigation sought to broaden our understanding of facial scarring and develop a novel tool for its objective evaluation. To this end, skin cancer as the most common etiology of facial scarring was reviewed. The scar scale literature was evaluated in the context of assessing scars through a biopsychosocial lens. Finally, the development of a novel scar scale was presented. Thirty-four individuals completed 13,056 ratings using a …

Pan-Cancer Analysis Of Telomerase Reverse Transcriptase (Tert) Isoforms, Mathushan Subasri

Electronic Thesis and Dissertation Repository

Reactivation of the multi-subunit ribonucleoprotein telomerase is the primary telomere maintenance mechanism in cancer, but it is rate-limited by the enzymatic component, telomerase reverse transcriptase (TERT). While regulatory in nature, TERT alternative splice variant/isoform regulation and functions are not fully elucidated and are further complicated by their highly diverse expression. In this thesis, I characterized TERT expression across normal and neoplastic tissues using TCGA and GTEx RNA-sequencing data. In doing so, I demonstrated the global overexpression and splicing shift towards full-length TERT in neoplastic tissue. Furthermore, my studies identified tumour subtype expression differences possibly regulated by subtype-specific characteristics, detailed heterogeneity …

Neoadjuvant Stereotactic Ablative Radiotherapy To Treat Early Stage Breast Cancer Patients: The Role Of Dce-Mri, Matthew Mouawad

Electronic Thesis and Dissertation Repository

The current standard of breast conserving therapy is lumpectomy followed by whole breast radiotherapy which is prohibitively long for many patients (4-6 weeks). In addition, the need for treating the whole breast has been questioned. The London Regional Cancer Program is enrolling early stage breast cancer patients in a prospective Phase I/II clinical trial (SIGNAL) to assess the safety/efficacy of neoadjuvant stereotactic ablative radiotherapy (SABR) to the tumour alone to reduce treatment times. This provides a unique opportunity to assess tumour response to SABR using non-invasive imaging. Patients received a pre-SABR dynamic contrast-enhanced (DCE)-MRI to guide target volume delineation. A …

Translational Control Of Stress Induced Breast Cancer Plasticity, Michael Jewer

Electronic Thesis and Dissertation Repository

Cancer cell plasticity, whereby stem-cell-like properties are acquired in response to stress, represents a major challenge in cancer treatment. Using cell line and patient-derived xenograft (PDX) models, we demonstrate that translational reprogramming occurs in response to stresses such as hypoxia and chemotherapy which elicits stem cell properties in breast cancer. Other stresses like chemotherapy demonstrate the translational inhibition that has been well characterized as an integral hypoxic cellular response. The inhibition of translation is primarily regulated at initiation by mTOR/4E-BP1 and PERK/eIF2α signalling. We identify previously undescribed 5’ untranslated regions (5’UTRs) of plasticity-associated genes like NANOG, SNAIL and NODAL. …

Elucidating Mechanisms Of Innate And Acquired Resistance To Pi3ka Inhibition In Head And Neck Squamous Cell Carcinoma, Kara M. Ruicci

Electronic Thesis and Dissertation Repository

The phosphoinositide 3-kinase (PI3K)/Akt/mechanistic target of rapamycin (mTOR) signalling pathway is aberrantly activated in most head and neck squamous cell carcinomas (HNSCCs). PI3K signalling drives cellular proliferation, protein synthesis and cell survival. Although numerous targeted agents are available to inhibit PI3K signalling, results have been variable and factors influencing response to PI3K inhibition (e.g. genomic aberrations, pathway interconnectivity, acquired drug resistance) are not well defined. In this thesis, we employ a multifaceted approach to elucidate the molecular underpinnings of biomarkers of response and mediators of resistance to PI3K inhibition in HNSCC. We began by combining a large panel of HNSCC …

Impact Of Feeding Tube Status On Health Outcomes For Individuals With Oropharyngeal Cancer, Nedeljko Jovanovic

Electronic Thesis and Dissertation Repository

Abstract

This study investigated differences in outcomes related to health, swallowing, and quality of life (QoL) for individuals with oropharyngeal squamous cell carcinoma (OPSCC) receiving either radiotherapy (RT) alone, or concomitant chemoradiotherapy (CRT). Differences were assessed based on whether patients received a feeding tube (FT group) or not (NFT group). Measures including the Functional Oral Intake Scale (FOIS), Performance Status Scale for Head and Neck Cancer (PSS-HN), M.D. Anderson Dysphagia Inventory (MDADI), and weight were collected for 126 individuals at baseline, and at 3, 6, and 12 months post-treatment. Data were analyzed to identify potential prognostic differences between the groups, …

Oncoplastic Surgery: Is It Time To Change? From Innovation To Adoption Using Mentorship Program, Eman Khayat

Electronic Thesis and Dissertation Repository

Oncoplastic surgery is considered the standard of care for breast cancer therapy in numerous Western World countries, particularly in Europe. Despite the advancement of knowledge, Canada still lags in adoption of oncoplasty into the standard surgical practice. In our study, a mentorship program was used to introduce oncoplastic surgery to practicing breast surgeons at LHSC. The change in perception and adoption of oncoplastic surgery were evaluated using semi-structured interviews, before and after the intervention, by qualitative thematic analysis method. Mentorship program was validated as a superior method of learning new surgical techniques by practicing surgeons, demonstrating acceptance of different levels …

Acute Pharmacologic Modulation Of Glioblastoma Ph Monitored By Chemical Exchange Saturation Transfer Magnetic Resonance Imaging, Mohammed Albatany

Electronic Thesis and Dissertation Repository

The response of tumor intracellular pH (pH_i) to a pharmacological challenge could help identify aggressive cancer. In addition, tumor pH_i may influence cell proliferation, apoptosis, chemotherapy resistance, and thermosensitivity. Chemical exchange saturation transfer (CEST) is a novel MRI contrast mechanism that is sensitive to cellular pH. More specifically, a CEST method called amine and amide concentration-independent detection (AACID) produces images weighted by intracellular pH (pH_i) and can be used to study pharmacologic pH modulation in tumours.

The overall goal of this thesis was to maximize the magnitude of intracellular tumour acidification using pharmacologic agents. Several …

Prostate Cancer Microparticles In Men Undergoing Radical Prostatectomy, Malcolm James Dewar

Electronic Thesis and Dissertation Repository

Objectives: To determine changes in prostate microparticle (PMP) concentrations in men with prostate cancer (PCa) after digital rectal examination (DRE), after radical prostatectomy (RP), and at follow-up.

Materials and Methods: 22 men were recruited before RP. Four blood specimens were collected – baseline (specimen 1), post-DRE (specimen 2), immediately post-RP (specimen 3), and follow-up (specimen 4). Pre- and post-DRE urine was collected (Specimen A and B respectively). Flow cytometric analysis of biofluids was performed with fluorescent-labeled antibodies against prostate-specific membrane antigen (PSMA) and polysialic acid. Total MP (TMP) and dual positive (PMP) events per µl of plasma or urine were …

The Application Of Self-Administered Nutrition Screening Tools And Evaluations Of The Impact Of Malnutrition On Quality Of Life In Individuals With Head And Neck Cancer, Mark J. P. Lynch

Electronic Thesis and Dissertation Repository

Abstract

Background: Individuals with head and neck cancer (HNCa) are at an increased risk of malnutrition. Therefore, self-administered nutrition screens which attempt to address their nutritional concerns may yield benefits for treatment outcomes and quality of life (QOL).

Methods: 34 participants (26 men, 8 women) completed one demographic and two QOL surveys, two nutrition self-screening tools, a nutrition assessment and an ease-of-use questionnaire. Results of the screens were compared to those of the assessment, and relationships between QOL, nutrition status, and demographics were examined.

Results: 32.3% of participants were identified as nutritionally compromised. The sensitivity and specificity for the PG-SGA …

Minimizing The Impact Of Disease While Maximizing Quality Of Life: An Exploration Of Resilience In Head And Neck Cancer Survivors, Chelsea A. Macdonald

Electronic Thesis and Dissertation Repository

Introduction: Individuals with head and neck cancer (HNCa) face myriad biopsychosocial challenges. Even after treatment completion, these challenges may continue to cause diminished quality of life (QoL). Resilience may serve to minimize the impact of HNCa and, thus, maximize QoL. The purpose of this study was to identify resilience in HNCa survivors and explore its potential relationship with QoL.

Methods: Thirty-one HNCa survivors completed three validated, self-report questionnaires pertaining to the collection of resilience and QoL data. Descriptive, correlational, and observational analyses were performed.

Results: Resilience was identified in the HNCa survivors and a positive correlation was found between resilience …

Developments In Pet-Mri For Radiotherapy Planning Applications, John Christian Patrick

Electronic Thesis and Dissertation Repository

The hybridization of magnetic resonance imaging (MRI) and positron emission tomography (PET) provides the benefit of soft-tissue contrast and specific molecular information in a simultaneous acquisition. The applications of PET-MRI in radiotherapy are only starting to be realised. However, quantitative accuracy of PET relies on accurate attenuation correction (AC) of, not only the patient anatomy but also MRI hardware and current methods, which are prone to artefacts caused by dense materials. Quantitative accuracy of PET also relies on full characterization of patient motion during the scan. The simultaneity of PET-MRI makes it especially suited for motion correction. However, quality assurance …

Mobilising Expertise And Resources To Close The Radiotherapy Gap In Cancer Care., D Rodin, J Longo, T Sherertz, M M Shah, O Balagun, N Wendling, Jacob Van Dyk, C N Coleman, M J Xu, S Grover

Oncology Publications

Closing the gap in cancer care within low- and middle-income countries and in indigenous and geographically isolated populations in high-income countries requires investment and innovation. This is particularly true for radiotherapy, for which the global disparity is one of the largest in healthcare today. New models and paradigms and non-traditional collaborations have been proposed to improve global equity in cancer control. We describe recent initiatives from within the radiation oncology community to increase access to treatment, build the low- and middle-income countries' radiation oncology workforce, mobilise more professionals from within high-income countries and raise awareness of the global need for …

Analysis Of Global Radiotherapy Needs And Costs By Geographic Region And Income Level., E Zubizarreta, Jacob Van Dyk, Y Lievens

Oncology Publications

Recent years have seen various reviews on the lack of access to radiotherapy often based on geographic regions of the world such as Africa, Asia Pacific, Europe, Latin America and North America. Countries are often defined by their national income per capita levels based on World Bank definitions of high income, upper middle income, lower middle income and low income. Within the world regions, there are significant variations in gross national income (GNI) per capita among the different countries, and even within similar income levels, large variations exist. This report presents the actual status of radiotherapy and analyses the current …

Translational Study Of Liver Cancer And Hypertrophy: Translich, Mauro Enrique Tun Abraham

Electronic Thesis and Dissertation Repository

Abstract

Background: Associating liver partition with portal vein ligation for staged-hepatectomy (ALPPS) is a technique for inducing accelerated hypertrophy in patients with insufficient future liver remnant (FLR). It remains unknown whether this hypertrophy may lead to rapid cancer cell dissemination and/or alteration of immune cell/function reconstitution in the FLR. We aimed to determine if the rapid hypertrophy during ALPPS procedure results in more circulating tumour cell (CTCs) dissemination and whether the FLR remains immunologically competent in patients with CRLM.

Methods: In our prospective, observational, 2-arm study, we assessed the utility of CTCs as an evaluation tool for disease dissemination. Moreover, …

Accuracy Requirements And Uncertainties In Radiotherapy: A Report Of The International Atomic Energy Agency., Debbie Van Der Merwe, Jacob Van Dyk, Brendan Healy, Eduardo Zubizarreta, Joanna Izewska, Ben Mijnheer, Ahmed Meghzifene

Oncology Publications

BACKGROUND: Radiotherapy technology continues to advance and the expectation of improved outcomes requires greater accuracy in various radiotherapy steps. Different factors affect the overall accuracy of dose delivery. Institutional comprehensive quality assurance (QA) programs should ensure that uncertainties are maintained at acceptable levels. The International Atomic Energy Agency has recently developed a report summarizing the accuracy achievable and the suggested action levels, for each step in the radiotherapy process. Overview of the report: The report seeks to promote awareness and encourage quantification of uncertainties in order to promote safer and more effective patient treatments. The radiotherapy process and the radiobiological …

Radiation Oncology Quality And Safety Considerations In Low Resource Settings: A Medical Physics Perspective, Jacob Van Dyk, Ahmed Meghzifene

Oncology Publications

The last few years have seen a significant growth of interest in the global radiation therapy crisis. Various organizations have quantified the need and are providing aid in support of addressing the shortfalls existing in many low-to-middle income countries (LMICs). With the tremendous demand for new facilities, equipment and personnel, it is very important to recognize the quality and safety challenges and to address them directly. An examination of publications on quality and safety in radiation therapy indicates a consistency in a number of the recommendations; however, these authoritative reports were generally based on input from high-resourced contexts. Here we …

Global Access To Radiation Therapy For Cervical Cancer: The Cost Of Inaction, Jacob Van Dyk, D Rodin, Timothy Paul Hanna, E Burger, Eduardo Zubizarreta, Mei Ling Yap, Michael Barton, Rifat Atun, Felicia Marie Knaul, Y Lievens, Mary K. Gospodarowicz, D A. Jaffray, M Milosevic

Oncology Publications

No abstract provided.

Investigating Stromal Contributions To The Regulation Of Cancer Progression, Krista M. Vincent

Electronic Thesis and Dissertation Repository

Tumours are not insular masses of proliferating cells, rather tumour cells evolve within a complex local environment complete with matrix, stromal, and immune components. Therefore, successful tumour growth and eventual metastasis is not determined solely by tumour cells themselves, but also by the fitness advantage or disadvantage conferred by their local environment. However, many of our current cancer models are composed solely of tumour cell isolates. As tumour fitness is dependent on the entire local cellular context, we were interested in characterizing the accuracy of cell lines as models of the tumour microenvironment, with a focus on the secreted Frizzled-related …