<p>In this thesis, two different vaccines were evaluated as adjuvant therapy for patients with colorectal cancer. The ability of the two candidate vaccines to generate antigen-specific cellular and humoral responses, respectively, was studied. The effectiveness of granulocyte colony stimulating factor (GM-CSF) as a cytokine adjuvant to augment the immune response was also examined.</p><p>The first vaccination strategy involved immunization with the recombinant tumor-associated protein, carcinoembryonic antigen (CEA). Recombinant CEA was administered at 4 different dose levels 7 times during one year. Peripheral blood samples were regularly analyzed during 36 months. This vaccination regimen induced a strong immunoglobulin 1 (IgG1) and IgG4 response, a moderate IgG2 response and a weak IgG3 response against CEA. GM-CSF markedly augmented the effect on IgG1 and IgG4 as well as the T cell response. In contrast, dose of rCEA had no or modest effect on induced immune responses. The response gradually increased during the 12 months immunization period. Responses of all three IgG subclasses and of T cells were protracted up to 36 months. The anti-CEA IgG titers related significantly to survival. Functional HLA-DR epitopes of CEA could be defined. These major histocompatibility class II epitopes may serve as putative components of a peptide-based vaccination strategy. </p><p>The other vaccine strategy consisted of the tumor-associated antigen epithelial cell adhesion molecule (Ep-Cam) expressed as a transgene in a viral vector, ALVAC. Patients were immunized subcutaneously/intradermally 3 times over 6 weeks and monitored for immune responses for 46 weeks. No anti-Ep-Cam specific humoral response was induced, but Ep-Cam specific type 1 T cells (interpheron-gamma production) were induced, mainly in the GM-CSF group. The cytotoxic cellular response appeared late, or a few months after the last immunization.</p><p>Both vaccines were well tolerated. Since GM-CSF was an important component for both regimens, immungenicity of this cytokine was assessed. Multiple immunizations with low dose GM-CSF were associated with a low incidence of GM-CSF antibodies that did not neutralize the biological effect of GM-CSF. </p><p>In conclusion, both vaccines are promising candidate vaccines. GM-CSF is necessary to induce a strong humoral and cellular immune response. Large clinical trials are urgently warranted to evaluate the clinical efficacy.</p>

In this thesis, two different vaccines were evaluated as adjuvant therapy for patients with colorectal cancer. The ability of the two candidate vaccines to generate antigen-specific cellular and humoral responses, respectively, was studied. The effectiveness of granulocyte colony stimulating factor (GM-CSF) as a cytokine adjuvant to augment the immune response was also examined. The first vaccination strategy involved immunization with the recombinant tumor-associated protein, carcinoembryonic antigen (CEA). Recombinant CEA was administered at 4 different dose levels 7 times during one year. Peripheral blood samples were regularly analyzed during 36 months. This vaccination regimen induced a strong immunoglobulin 1 (IgG1) and IgG4 response, a moderate IgG2 response and a weak IgG3 response against CEA. GM-CSF markedly augmented the effect on IgG1 and IgG4 as well as the T cell response. In contrast, dose of rCEA had no or modest effect on induced immune responses. The response gradually increased during the 12 months immunization period. Responses of all three IgG subclasses and of T cells were protracted up to 36 months. The anti-CEA IgG titers related significantly to survival. Functional HLA-DR epitopes of CEA could be defined. These major histocompatibility class II epitopes may serve as putative components of a peptide-based vaccination strategy. The other vaccine strategy consisted of the tumor-associated antigen epithelial cell adhesion molecule (Ep-Cam) expressed as a transgene in a viral vector, ALVAC. Patients were immunized subcutaneously/intradermally 3 times over 6 weeks and monitored for immune responses for 46 weeks. No anti-Ep-Cam specific humoral response was induced, but Ep-Cam specific type 1 T cells (interpheron-gamma production) were induced, mainly in the GM-CSF group. The cytotoxic cellular response appeared late, or a few months after the last immunization. Both vaccines were well tolerated. Since GM-CSF was an important component for both regimens, immungenicity of this cytokine was assessed. Multiple immunizations with low dose GM-CSF were associated with a low incidence of GM-CSF antibodies that did not neutralize the biological effect of GM-CSF. In conclusion, both vaccines are promising candidate vaccines. GM-CSF is necessary to induce a strong humoral and cellular immune response. Large clinical trials are urgently warranted to evaluate the clinical efficacy.

Most cases of lung cancer have a commonly-understood behavioral etiology. Thus, individuals with lung cancer are often blamed for their illness by others and may therefore seek to avoid this blame by concealing their diagnosis from others. This study sought to determine the prevalence of diagnosis concealment, examine potential predictors of concealment, and test parts of a cognitive-affective-behavioral model of the effects of concealing a concealable stigma among individuals receiving treatment for lung cancer. With regard to predictors of concealment, it was hypothesized that concealment would be positively associated with male gender, introversion, and trait social anxiety and would be negatively associated with social support and the use of seeking guidance and support as a coping strategy. Hypothesized correlates of concealment included poorer self-esteem as well as greater anxiety, cancer-specific distress, and social avoidance. A sample of 117 participants receiving chemotherapy or radiation for stage I-IV non-small cell lung cancer and limited to extensive stage small cell lung cancer was recruited during routine outpatient visits. A medical chart review was conducted to assess clinical factors and participants completed a standard demographic questionnaire as well as measures of coping strategies, introversion, trait social anxiety, social avoidance, social support, anxiety, depression, cancer-specific distress, self-esteem, perceived stigma, public self-consciousness, and private self-consciousness. Results indicated that 31% of participants concealed their diagnosis from others since their diagnosis and 26% concealed their diagnosis in the month preceding their participation in the study. Hypotheses regarding predictors and correlates of concealment were not supported. However, exploratory analyses identified use of alcohol, recency of a recurrence of lung cancer, use of positive reappraisal as a coping strategy, and social support as predictors of concealment as well as internalized shame as a correlate of concealment. These findings serve to extend existing literature on concealing a concealable stigma and support parts of an existing model on the effects of concealment. Future research should aim to test the impacts of concealment in the context of certain social situations to examine longitudinal relationships between predictors and consequences of concealment.

Low and middle-income countries (LMICs) around the world are experiencing a global cancer crisis. For treatable disease, cancer specific mortality in LMICs is much higher than in high-income countries. Botswana is a middle-income country in Sub-Saharan Africa that had its population decimated by the AIDS epidemic. In the aftermath and due to the successful implementation of an anti-retroviral program, patients are living longer and are developing cancer. Cervical cancer is one of the leading causes of death in women around the world, but it is curable. Patients in Botswana live far from treatment centers and therefore often present with locally advanced disease that can be cured with a combination of chemotherapy, external beam radiation therapy and brachytherapy. The goal of this present study is to describe the challenges and implementation of brachytherapy in the country of Botswana in 2012 and to report its uses within the cervical cancer population between 2012 and 2014. The government of Botswana recognized that there was a need for in country brachytherapy to help reduce the cervical cancer burden. A public-private partnership was negotiated through the government of Botswana in order to bring brachytherapy into the country. In March 2011, a Nucletron HDR-Brachytherapy unit that uses Ir-192 was installed at Gaborone Private Hospital. Longitudinal support from international partners provided instruction in insertion, dosimetry, physics and management of complications. The initial burden of patients presented with severe cervical fibrosis and vaginal stenosis due to late presentation of disease. This resulted in numerous complications in the first treatments, which included failed insertions, perforations and bleeding. Following training and support from international partners, complications have been reduced. There are about 45 insertions performed each month, with an average of 3 insertions per patient. Introduction of HDR Brachytherapy to Botswana has led to decreased treatment time, reduced complications, increased patient compliance and projected improved survival. Implementation of brachytherapy was facilitated by a public-private partnership and onsite mentorship by expert clinicians. Further research is needed to evaluate impact on patient quality of life and survival, and whether this experience can be replicated for other tumor sites.

No description available.

<p>BACKGROUND AND OBJECTIVES: In 2007, the Joint Oncology Drug Review (JODR) (which ultimately evolved into a permanent body called the pan-Canadian Oncology Drug Review (pCODR)) was established to make recommendations to Canada’s provincial and territorial public drug plans regarding the funding (i.e. reimbursement) of new cancer drugs. The JODR/pCODR exists alongside Canada’s Common Drug Review, which provides reimbursement recommendations to Canada’s provincial and territorial public drug plans for drugs in all other disease areas. Using an economic perspective, this thesis (composed of three separate papers) appraised: the rationale for the JODR/pCODR’s establishment, the JODR/pCODR’s resource allocation goals, and the JODR/pCODR’s decision-making criteria and decision rules. The overarching theme linking the three thesis papers is whether the JODR/pCODR facilitates Canada’s provincial drug plans’ ability to achieve a goal of maximizing health benefits with available resources.</p> <p>METHODS: For the first two papers, a series of questions regarding the JODR’s establishment, resource allocation goals, decision-making criteria and decision rules were posed. The questions were answered by reviewing peer-reviewed literature and/or JODR/pCODR-published materials and by applying fundamental principles underlying an economic perspective. By again applying these same principles, the third paper in this thesis addressed the challenges associated with striving to simultaneously achieve the pCODR’s resource allocation goals of maximizing health benefits with available resources and striving to improve access to a more consistent standard of care across Canada.</p> <p>FINDINGS AND CONCLUSION: The various issues identified in this thesis suggest that the JODR/pCODR is unlikely to facilitate Canada’s provincial drug plans’ ability to achieve a goal of maximizing health benefits with available resources for several reasons (which are described in detail in the thesis papers). It is my hope that this thesis will encourage further debate regarding the strengths and limitations of the pCODR and regarding other possible approaches for managing the public reimbursement of cancer drugs.</p> / Doctor of Philosophy (PhD)

Cancer cell invasion and metastasis is one of the hallmarks of cancer and is frequently the fatal stage in disease progression. One of the key cellular processes underlying invasion and metastasis is cell migration, which is highly dependent on dynamic changes in the actin cytoskeleton. Reactive oxygen species (ROS) are frequently found at elevated levels in cancer and promote disease progression particularly by increasing invasion and metastasis. Although it is known that ROS, specifically H2O2, mediate their downstream effects through the oxidation of proteins on key cysteine residues, very little is known about the direct protein targets of ROS and how the resulting protein oxidation might contribute to cell migration, invasion and metastasis. I have demonstrated that the ROS, H2O2, is produced at increased levels in migrating cells, predominantly at the tips of cell protrusions. Furthermore, I established that protein oxidation is increased in migrating cells and identified the actin binding protein cofilin as one of these oxidised proteins. I have also provided evidence that, when oxidised, cofilin forms oligomers and has a reduced ability to decrease F-actin levels in vitro, which was dependent on cysteine residues 139 and 147. Moreover, I have shown that the oxidation of these cysteine residues is important for directional cell migration and adhesion. Taken together my results provide a direct link between the increased production of ROS at the leading edge of migrating cells and dynamic changes in the actin cytoskeleton that take place in this region to enable cell migration. As the invasion and metastasis of cancer is largely dependent on cell migration, these findings could potentially lead to the development of new ways to target this stage in disease progression.

Chemokines are a family of low-molecular weight proteins that mediate their effects through binding with chemokine receptors (a group of seven trans-membrane spanning G-protein coupled receptors). Chemokines are well known for their role in leukocyte trafficking, although they also mediate a range of other physiological functions including cell proliferation, growth and differentiation. Chemokines are integral to the development and functioning of the immune system and are implicated in the pathogenesis of a wide range of diseases including autoimmune disorders, HIV infection and malignancies. Non-Hodgkin’s lymphoma (NHL) is a malignancy of the lymphoid system, which can affect any tissues in the body but has a predilection for the secondary lymphoid organs and the bone marrow. NHL represents a heterogeneous group of disorders with variations in presentation and prognosis. Whilst there have been improvements in overall survival in the last few decades following developments in treatment there is still a significant mortality associated with NHL as well as significant morbidity associated with the treatments required to control the disease or affect a cure. There is increasing evidence that chemokines and their receptors play a role in the pathogenesis of NHL with increased chemokine receptor expression seen in certain subtypes. Chemokines have also been shown to influence prognosis in particular NHL subtypes. This thesis describes studies to examine the relationship between constitutive chemokine receptor expression and NHL subtype with subsequent correlation between chemokine receptor expression and outcome. Results from studies on clinical samples obtained from patients with a range of B-cell NHL subtypes revealed significant differences in chemokine receptor expression between subtypes. Predominantly these differences were noted with the receptors CCR4 and CCR7. CCR4 has previously been examined in relation to T-cell lymphomas and high CCR4 expression has been associated with an adverse prognosis in adult T-cell leukaemia/lymphoma. However, systematic examination of CCR4 in B-cell NHL has not been done before. In this study CCR4 expression was seen in samples of diffuse large B-cell lymphoma (DLBCL), mantle cell lymphoma (MCL), MALT lymphoma and Burkitt’s lymphoma. Furthermore high CCR4 expression was associated with a significantly improved survival in patients with DLBCL. CCR7 expression was significantly higher in cases of MCL and chronic lymphocytic lymphoma/small lymphocytic lymphoma (CLL/SLL), this however did not equate to differences in outcome. The high expression of CCR7 in MCL and CLL/SLL does however make this receptor an ideal target for the development of targeted therapies. Further studies in this thesis describe strategies used to target the chemokine system with cytotoxic agents. CCR7 was chosen for targeting experiments due to its restricted expression (naïve T-cells, memory T-cells, dendritic cells and subsets of B-cells) in normal tissues, the fact that it controls homing of leukocytes to lymph nodes, and that is the second most commonly reported chemokine receptor detected in cancers. The first approach for targeting the chemokine system used radio-labelled chemokines to induce cytotoxicity in cells expressing the cognate receptor. Unfortunately, the results from this were not conclusive and further studies are required to explore this approach. The second approach described in this thesis entailed the potential use of oncolytic adenoviral gene therapy. This approach requires the redirection of adenoviral tropism from the coxsackie and adenovirus receptor (CAR) and through CCR7. This was successfully achieved in cell lines engineered to express and those endogenously expressing CCR7 by ‘shrouding’ the virus in CCL19. However, background infection was high and this led to the engineering of an adenoviral vector incorporating a peptide within the viral knob protein to allow for more efficient ‘shrouding’ of the virus and thus more efficient redirection of the virus. However, final experiments with this vector were not performed due to time constraints. The final part of this thesis relates to the characterisation of EL4 cells (a murine T-cell lymphoma cell line) for use as a potential in-vivo mouse model for targeting experiments. Following injection into the flank of C57/BL6 with these cells, measurable tumours develop. It was demonstrated that this cell line expressed CCR7, and finally after a number of modifications, it was shown that adenoviral tropism could be redirected through chemokine receptors on the surface of these cells. In summary the results in this thesis shows for the first time that CCR4 is expressed across a number of B-cell NHL subtypes and that this is associated with outcome in DLBCL. Results also demonstrate that therapeutic targeting of CCR7 is a reasonable therapeutic approach in NHL. In addition, redirection of oncolytic adenoviral vectors through chemokine receptors provides a potential strategy for obtaining this targeted therapy. Finally, EL4 cells have the potential to be used as an in-vivo mouse model for CCR7 targeted therapies.

Published Article / The aim of this research was to identify the design aspects necessary to create an aesthetically appealing playroom environment to aid the well-being of hospitalised oncology children at a public hospital in Bloemfontein, South Africa. The methodology design is overall qualitative within the interpretivist paradigm with a triangulation methodology design with explanatory components. These components consisted of a literature review which was further explored by means of a qualitative questionnaire. The playroom was created as part of a community project according to the literature review and questionnaire after which semi-structured individual interviews were conducted with the children themselves.

Despite expressing antigens that can induce immune surveillance and immune eradication, tumours demonstrate the capacity to evade anti-tumour immunity. Recently, this has been attributed to the ability of tumours to induce a local immunosuppressed micro-environment, which is a major obstacle to successful natural and vaccine induced anti-tumour immunity. Soluble factors such as transforming growth factor beta (TGFβ), and interleukin 10 (IL-10), released by cancer and stromal cells, are thought to play a significant role in this local immunosuppression. In order to assess the influence of antagonising these soluble factors locally on tumour biology and tumour immunity, a murine CT26 colorectal carcinoma model that can express cytokine antagonists under Doxycycline (Dox) control was engineered. Two stable CT26 cell lines expressing Dox-inducible soluble extracellular domain of TGFβ receptor II (STGFβRII) or soluble extracellular domain of IL-10 receptor (SIL-10R), were established. Expression of STGFβRII in vitro and in vivo was only evident after Dox treatment. When Dox was administered directly following subcutaneous (s.c.) inoculation of STGFβRII-expressing CT26 cells into Balb/c mice, tumour growth was significantly suppressed. Interestingly, inducing STGFβRII in well-established tumours showed less suppression of tumour growth. To assess the effect of expressing STGFβRII on tumour immunity the RNA expression of 22 common cytokines was measured in the tumours of mice receiving Dox and control mice. The levels of some of these cytokines were modulated by STGFβRII expression (e.g TGFβ,Tnfsf9, IL-2). We also tested for any additive effect between expressing STGFβRII, and the administration of anti-CTLA-4 antibody on tumour growth, and tumour immunity. The model described here could help address various limitations seen previously in studies of TGFβ blockade. It provides means of effective local antagonism, and it addresses immunological endpoints which have been limited in previous studies. Because of its tight regulation, the model also allows identification of the best timing of TGFβ blockade alone or in combination with other immunotherapeutics.