Class of 2016 Abstract / Objectives: To determine the number of patients treated with eribulin who required an alternate dosing schedule other than “day 1/day 8” due to side effects. Methods: Chart reviews were conducted on all patients who met inclusion criteria. Data collected included patient demographics, history of surgery/radiation, number of past chemotherapy treatments, and lab values prior to each eribulin cycle. Results: A total of 37 patients met inclusion criteria for this study. Ten patients were initially started on the “day 1/day 8” schedule and 3 of those patients required a change to the extended “day 1/day 15” schedule. The remaining 27 patients were started on the extended schedule. Conclusions: The number of patients requiring a dosing schedule change due to side effects was not statistically significant. This finding was due to the fact that the majority of patients were started on an alternate dosing schedule in the beginning of treatment. More extensive studies would be required to determine if a majority of patients would require this alternate dosing schedule, and if this should be initiated in all patients starting on eribulin.

A case is presented in which flow cytometric and cytogenetic analysis was done on a biopsy from a highly anaplastic metastatic adenocarcinoma. Flow cytometric analysis of DNA content failed to show a significant population of aneuploid cells. However, histologic examination revealed a substantial number of tumor cells, and cytogenetic analysis produced chromosome counts ranging from 20 to 144.

Medulloblastoma (MB) is the most common malignant pediatric brain tumour. Of its four distinct molecular subgroups (WNT, SHH, Group 3, and Group 4), Group 3 MB patients hold the worst clinical prognosis due to their high incidence of tumour recurrence and metastasis to the spinal leptomeninges. Relapsed Group 3 MB patients, particularly those with MYC amplification (known as Group 3𝛾), carry a mortality rate of nearly 100%, given the paucity of effective therapeutic options currently available. The most common cause of mortality amongst these patients is leptomeningeal metastasis, yet this metastatic disease is poorly characterized. Our understanding of MB tumour recurrence and leptomeningeal metastasis is further encumbered by the rare clinical opportunities at which specimens may be collected from relapsed patients. We were able to circumvent this obstacle by establishing a patient-derived xenograft mouse-adapted therapy model, which mimics the treatments administered in the clinic and in turn, recapitulates both local and metastatic human MB recurrence. This model system enabled the collection of valuable, patient-derived Group 3𝛾 MB tumour cells from the spinal leptomeninges at relapse. It provides an opportunity for chemical screening, with the aim of identifying small molecule inhibitors capable of eradicating these cells. Existing studies on MB leptomeningeal dissemination at diagnosis suggest that effective treatments may target signalling proteins, such as phosphatidylinositol 3-kinases and histone deacetylases (HDACs). Therefore, I hypothesized that selective kinase and HDAC inhibitors would pose as effective therapies against Group 3𝛾 MB metastatic recurrences. In this thesis, I conducted a high-throughput screen of 640 kinase inhibitors and robust testing of novel HDAC6-selective inhibitors against these treatment-refractory, metastatic cells. Here, I showed that metastatic recurrences of Group 3𝛾 MB are therapeutically vulnerable to selective inhibitors of checkpoint kinase 1 (CHK1), platelet-derived growth factor receptor beta (PDGFRβ), and HDAC6. Functional studies demonstrated that these inhibitors selectively target the aggressive, migratory Group 3𝛾 MB cells, while sparing healthy neural stem cells. They also showed effective blood-brain-barrier penetration in silico and in vitro, while significantly reducing MB tumour cell properties that are often associated with treatment failure. Taken together, my thesis highlights specific inhibitors of CHK1, PDGFRβ, and HDAC6 that effectively target MB tumour cells that fuel treatment-refractory leptomeningeal metastases. With additional preclinical validation, these compounds may serve as potent therapeutic options to extend survival and improve the quality of life for patients that are ostensibly limited to palliation. / Thesis / Master of Science (MSc) / Medulloblastoma is an aggressive brain cancer in children. While current standard treatment improves patient survival, 30-40% of all medulloblastoma patients relapse at local (brain) or metastatic (spine) sites. Medulloblastoma metastatic recurrences remain poorly understood, yet they result in an alarmingly high mortality rate amongst patients due to inadequate treatment options currently available. Specific molecular targets are common in both medulloblastoma and metastatic cancer research. These targets are particularly important in governing cell signalling pathways that regulate tumour growth and migration. Therefore, treatment against these targets may be effective at preventing medulloblastoma metastatic recurrences. As the collection of local and metastatic tumour samples at patient relapse are rare, the Singh lab developed an animal model that mimics human medulloblastoma recurrence. In this thesis, recurrent medulloblastoma metastases were isolated from our established animal model and tested against compounds that inhibit the specific molecular targets previously implicated in medulloblastoma and other metastatic tumours. We identified potent compounds that effectively target these metastatic cells. Next, we determined which compounds spared healthy cells and were able to penetrate the brain, given our future objective of targeting these MB cells from their source to ultimately prevent metastasis. The identified compounds substantially reduced the ability of these cells to divide. With further investigation, these compounds may pose as effective therapeutic agents to treat human medulloblastoma patients with metastatic recurrences.

At least 50% of people will develop cancer at some point during their lifetime and half these will end in fatality. Improving patients’ prognosis relies on early and accurate diagnosis and treatment. Current diagnostic methods are based on histopathological analysis and are time-consuming, expensive and require biopsy. Raman spectroscopy can measure subtle biochemical changes and provides a rapid, non-destructive and objective technique that can be used in vivo for identifying pathological changes in tissue samples. This study investigates both a standard Raman spectrometer system and also a Raman needle probe for their use as diagnostic techniques and clinical tools. Oesophageal, femoral and head and neck lymph nodes were analysed in this study. Metastatic lymph nodes from the three areas could be identified from the non-cancer lymph nodes with a sensitivity of 71% and specificity of 89%. Lymphoma was identified from non-cancer lymph nodes with a sensitivity of 64% and specificity of 86%. It was observed that oesophageal nodes often contained carbon particles, clinically diagnosed as anthracosis. These nodes were much harder to study than the femoral or head and neck, due to strong Raman signal detected from the carbon particles. Lymph nodes are embedded in adipose tissue and as a consequence, very strong lipid peaks were frequently observed in spectra. Spectral differences were exhibited in the measurements of the lymph nodes from the three different anatomical regions. A comparison of the point measurements and mapped data showed no difference in classification. Therefore, indicating that just a few measurements can be sufficient enough sampling to represent a specimen, and demonstrates the practicability of Raman use in vivo for rapid analysis. The Raman needle probe feasibility study showed its potential for in vivo use for real-time diagnosis and as a surgical tool to support biopsy. A sensitivity and specificity of 80% and 79% for the identification of non-cancer head and neck lymph nodes from non-cancer provides similar accuracies to the standard Raman approach, therefore supports its viability for use as a diagnostic tool.

Les cellules Natural Killer (NK) sont de grands lymphocytes granuleux capables de rapidement éliminer des cellules tumorales et des cellules infectées par des virus sans immunisation au préalable. Au cours de ma thèse, j’ai analysé plusieurs paramètres impliqués dans la reconnaissance et la lyse des cellules de mélanome par les NK. J’ai montré à partir d’analyses ex vivo que les NK sanguines de patients atteints de mélanome métastatique (stade III-IV) présentent un faible potentiel lytique. Cependant, de telles NK provenant de patients mélanomes de tout stade clinique activées in vitro par de l’IL-2 lysent efficacement des lignées de mélanome métastatique. L’analyse du phénotype de NK circulantes de patients stade IV a montré une diminution de l’expression du récepteur activateur NKp46/NCR1 comparé aux NK de donneurs sains. J’ai également montré une corrélation positive entre l’expression du NKp46 à la surface des NK et la durée du stade IV. Pour caractériser les NK infiltrant le mélanome, J’ai analysé ex vivo les NK infiltrant des ganglions métastatiques (GG) provenant de 25 patients en stade III. Les GG de patients mélanomes contiennent une population unique de NK CD56brightCD16+ représentant 50% des NK dans ces GG qui expriment fortement les récepteurs NK NCR, NKG2D, KIRs et produisent une plus forte proportion de perforin comparée aux NK CD56brightCD16- ganglionnaires. Les NK immunsélectionnées à partir de GG et activées avec de l’IL-2 ou de l’IL-15 lysent rapidement et efficacement des lignées cellulaires de mélanome. Elles sont caractérisées par des capacités lytiques supérieures aux NK sanguines. De plus, afin d’évaluer l’impact des NK au cours du mélanome, j’ai analysé in situ les NK infiltrant des ganglions sentinelles positive et négatif ainsi que des tumeurs cutanées primaires. Les NK sont faibles dans les GS ; cependant nous avons montré que le nombre de NK infiltrant ces ganglions sentinelles est associé à une plus forte rechute à cinq ans des patients. Les cellules NK infiltrant les tumeurs cutanées sont présentes préférentiellement dans la zone peritumorale et sont très rares dans la tumeur.Chez les patients atteints de mélanome, les NK sanguines et infiltrant les tumeurs ont des caractéristiques phénotypiques et fonctionnelles différentes. Une meilleure compréhension de telles différences doit être prise en compte, ainsi la biologie des NK et de leur modulation au cours du cancer est nécessaire pour développer une stratégie thérapeutique à base de cellules NK efficace. / Cytotoxic immune effectors can control the development and growth of certain solid tumours. Among these cytotoxic effectors, NK cells are capable of rapidly eliminating tumour cells and virus-infected cells without prior immunization.The objectives of my thesis were to evaluate the potential role of NK cells in the immune response against melanoma. First, I have characterized the functional status of blood NK cells from melanoma patients at different stages of the disease. I showed that ex vivo NK cells from most advanced stage III-IV patients display low lytic potential. However, IL-2-activated NK cells from patients efficiently lyse melanoma cells and that independently to the clinical stage. Moreover, the expression of the activating receptor NKp46/NCR1 by blood NK cells was decreased in stage IV patients compared to healthy donors, and a positive correlation between NKp46 expression by NK cells and the duration of stage IV was found. I have also characterized ex vivo NK cells infiltrating metastatic lymph nodes (M-LN) from stage III melanoma patients. I have identified in M-LN a unique subpopulation of mature CD56brightCD16+ NK cells that expressed higher NCR, NKG2D, KIRs, and perforin levels than CD56brightCD16- NK cells counterpart. NK cells from M-LN activated with IL-2 or IL-15, rapidly lysed metastatic melanoma cell lines with higher efficiency than autologous blood NK cells. Finally, to determine if NK cells display a prognostic value, I analysed by immunohistochemistry NK cells and other immune cells infiltrating positive and negative sentinel lymph nodes (SLN). SLN are characterized by high densities of macrophages and endothelial cells, even higher in SLN+. Few NK cells and Granzyme B+ cells infiltrate SLNs while CD8+ T cells are numerous. Moreover, numbers of NK cells in SLN correlated with higher rate of 5 year-relapse of patients. Compared to SLN, primary cutaneous melanomas contain high numbers of NK cells that are preferentially localized in the periphery of the tumour and are not related to the Breslow. My findings showed that in melanoma patients, circulating and tumour infiltrating NK cells display unique phenotypic and functional characteristics, indicating that tumour may alter their function. However, they respond to cytokine activation and acquire antitumor lytic potential. In the new landscape of melanoma treatment, NK cells are worthy to be considered for combined treatment with BRAF inhibitors.

No description available.

Palliative radiotherapy (PRT) is proven to be effective in palliation of symptoms for end-stage cancer patients. However, little is known about its utilization at the end of life. This research aims to examine the utilization and the practice patterns of PRT at the end of life for cancer patients in British Columbia using population-based data. The pattern observed for PRT1Y dose-fractionation practice in BC are in line with published clinical guidelines and evidence from the literature, which advises “proper” use of PRT in BC as delivered to cancer patients at the end of life. However, after controlling for age, primary cancer site, and survival time, geographic access is found to be significantly associated with PRT1Y utilization. Variations found in PRT1Y rates by geographic access, which is operationalized by the Health Services Delivery Area (HSDA) and travel time, suggests potential underutilization of PRT1Y for patients with suboptimal access. / Graduate / 0992 / 0769 / 0574 / jinhuang@uvic.ca

Multidrug resistance refers to the simultaneous resistance to structurally and mechanistically unrelated cytotoxic drugs. Chronic administration of cytotoxic drugs to patients with metastatic breast cancer results in the development of multidrug resistance, thus rendering chemotherapy unsuccessful. One mechanism by which multidrug resistance is conferred is the decreased intracellular drug accumulation due to the upregulation of the ATP-binding cassette (ABC) transporters. Jadomycins are polyketide-derived natural products produced by the soil actinomycetes Streptomyces venezuelae, ISP 5230. Jadomycins exhibit anticancer, antibacterial and antifungal activities. Pilot work in our laboratory demonstrated that jadomycin B exhibited similar cytotoxic effects in drug-sensitive and drug-resistant cancer cells. We hypothesize that jadomycins are poor substrates of ABCB1, ABCC1 and ABCG2 efflux transporters, and consequently will exhibit higher intracellular accumulation, which results in improved cytotoxic efficacy over existing chemotherapeutics that are rapidly effluxed by ABC transporters. Using methyltetrazolium (MTT) cell viability assays, the cytotoxic efficacy of nine jadomycin analogues (DNV, L, B, SPhG, F, W, S, T and N) in drug-sensitive and drug-resistant MCF7 breast cancer cells was evaluated. Jadomycin B, L, S and T were found to be equally toxic to drug-sensitive and drug-resistant ABCB1, ABCC1 or ABCG2-overexpressing MCF7 breast cancer cells. The inhibition of ABCB1, ABCC1 or ABCG2 efflux transporters with verapamil, MK-571 or ko143, respectively, did not significantly augment the cytotoxic effects of jadomycin DNV, L, B and S in drug-resistant MCF7 cells, suggesting that these jadomycins are poor substrates of the targeted transporter. Furthermore, all nine jadomycin analogues did not increase the intracellular accumulation of ABCB1, ABCC1 or ABCG2 probe fluorescent substrates in HEK-293 cells, indicating that these jadomycins do not inhibit the efflux function of the transporters. We conclude that jadomycins B, L and S are effective agents in the eradication of resistant breast cancer cells grown in culture, and that the ability of specific jadomycins to retain cytotoxic efficacy in resistant cells stems from their limited interactions with ABCB1, ABCC1 or ABCG2 efflux transporters.

No description available.

The detection or exclusion of metastatic liver involvement is critical in the management and prognosis of patients with malignant disease. Noninvasive imaging modalities such as computed tomography, ultrasound, and technetium colloid liver scan are highly sensitive but nonspecific. Serum alkaline phosphatase is of similar value. A blind liver biopsy by the Menghini technique is often done to confirm the diagnosis, but its yield is low. We prospectively evaluated 74 patients using blind Menghini needle biopsy and concurrent Chiba fine-needle aspiration biopsy (FNAB) techniques. A positive diagnosis of malignancy was made in 30 patients (41%). In only 25 (34%) was the diagnosis made by Menghini biopsy, while Chiba FNAB confirmed the diagnosis in all 30 patients. Thus, concurrent use of both needles increased the diagnostic accuracy by 7%. Seven additional patients, considered to have one or more contraindications for the Menghini biopsy, underwent Chiba FNAB alone; the diagnosis was confirmed in all without complication. We conclude that FNAB alone or in combination with Menghini biopsy is valuable and safe in the diagnosis of metastatic liver disease.