The province of Manitoba has set a goal of reducing time from suspicion of cancer to treatment to a target of sixty days. To attain this goal, a baseline understanding of current time intervals is required. This study examined system, diagnostic and treatment delay in adult patients (> 17) diagnosed with Lymphomas from 2005 to 2010 using administrative data (Manitoba Cancer Registry, Manitoba Health billing data and Hospital Abstract data) and a chart review of a random subset of patients. A triangulated data approach was used to identify suspicion of lymphoma and milestones in the patient journey and to measure delays in diagnosis and treatment. Using an iterative consultative process, an algorithm was built to identify index events likely related to subsequent lymphoma diagnosis. Then, claims data was searched for a referring provider for each index event. The last visit with a referring provider, prior to the first index event, was selected as date of high suspicion. The study found that 14.8% of patients met the provincial target of less than sixty days from suspicion to treatment. Median time from high suspicion to treatment, referred to as system delay, was 128 days and the median time from diagnosis to treatment was 41 days. Time to diagnosis accounted for two thirds of system delay. In conclusion, this study demonstrated the merit of a triangulated approach. As well the clinical pathway developed and the target timelines for milestones have operational value and can be used to direct process improvements to shorten delays for future patients. / February 2017

Background: The t(8;14) translocation in Burkitt’s lymphoma (BL) was the first non-random cytogenetic lesion to be described in lymphoproliferative disorders. This lesion occurs in 75-85% of all BL cases. However, the breakpoints in this cytogenetic lesion are very variable and far apart such that the t(8;14) translocation is not always amenable to standard polymerase chain reaction analysis. This is mainly due to the inability of the Thermus aquaticus (Taq) polymerase enzyme to synthesize long DNA products. Long range polymerase chain reaction (LD-PCR) with a high fidelity polymerase enzyme mix capable of longer PCR product synthesis has recently become available. In early studies, LD-PCR appeared to be capable of amplifying the t(8;14) translocation in the majority of published sporadic Burkitt’s lymphoma analyses. The utility of t(8;14) translocation LD-PCR for routine use in the diagnosis of BL in our setting has not yet been studied. The aim of this study was to establish and optimize the t(8;14) LD-PCR technique and to apply it in the retrospective analysis of all BL diagnosed in the University of the Witwatersrand teaching hospitals in a ten year period from January 1994 to December 2003. Materials and methods: High molecular weight non-degraded DNA was extracted from control cell lines as well as stored, unstained bone marrow slides remaining after routine diagnostic workup of previously identified Burkitt’s lymphoma patients. Three hundred nanograms of patient and control DNA were amplified with the LD-PCR high fidelity polymerase enzyme mix under reaction conditions which were optimized using the tissue plasminogen activator (tPA) gene as well as known Burkitt’s lymphoma cell lines as controls. Each control and patient DNA sample was amplified with tPA primers as well as four pairs of MYC/IgH primer sets. The resulting amplicons were size fractionated on an agarose gel and visualized with ethidium bromide under ultraviolet (UV) light. The fractionated DNA fragment sizes were compared to those of the t(8;14) translocation positive controls, tPA controls and known DNA molecular weight markers. Results: One hundred and ten Burkitt’s lymphoma diagnoses were made in the three teaching hospitals of the University of the Witwatersrand from January 1994 to December 2003. Bone marrow involvement by BL was present in 84 of these cases. Archival bone marrow slides were available in 74 of the 84 BL patients. Intact high molecular DNA on which the t(8;14) LD-PCR analysis could be performed was present in 41 of the 74 BL patients. In the presence of appropriate controls, an t(8;14) translocation specific product was demonstrable by t(8;14) LD-PCR analysis in only 6 of 41 BL patients. Conclusion: In this t(8;14) LD-PCR retrospective analysis of a large number known Burkitt’s lymphomas, the diagnostic yield in carefully selected patients was extremely poor. With five primer pairs required per BL sample analysis, this technique was found too labour intensive and costly in our hands making it unsuitable for routine diagnostic use. The reasons for the poor diagnostic yield remains unclear and may need to be explored in future studies. Emerging alternative techniques for the diagnosis of BL such as fluorescence in situ hybridization and microarray gene expression analyses may prove to be better diagnostic tools than LD-PCR in its current form.

Autophagy, a cellular self-degradation process, plays important roles in cancer development and progression. Autophagy can be inhibited by the anti-apoptotic protein BCL-2 which binds and sequesters the autophagy essential protein Beclin-1, therefore preventing autophagy induction. It is currently unclear whether BCL-2 inhibits autophagy as well as apoptosis in follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL) which frequently express BCL-2 at high levels. This study aimed to determine (1) the role of BCL-2 in the basal level autophagy status and autophagy flux in primary FL and DLBCL samples, and lymphoma cell lines at both the gene and protein levels; (2) whether aberrant autophagy activity in these lymphoma patients is associated with clinical outcome. We initially found that the BCL-2 inhibitor ABT-737 concurrently induced autophagy and apoptosis in BCL-2HIGH DLBCL cell lines. Blocking autophagy degradation with chloroquine sensitised BCL-2HIGH cells to ABT-737-induced cell death, indicating that acquired autophagy acts as a cytoprotective mechanism in these cells. Expression levels of autophagy-related genes were analyzed by qRT-PCR. The BCL-2HIGH cell line Su-DHL4 showed up-regulation of more autophagy machinery genes at both the basal level and following starvation-induced autophagy compared with the BCL-2LOW cell line. These results suggest that inhibition of BCL-2 can induce cytoprotective autophagy, but overexpression of BCL-2 alone may increase basal level autophagy by inhibiting apoptosis. The expression levels of autophagy-related genes were examined in purified primary FL and DLBCL B cells or un-purified whole FL and DLBCL tumour tissue biopsies and compared with non-malignant reactive lymph nodes. A number of autophagy machinery genes were significantly up-regulated in malignant samples. In particular, more autophagy machinery genes showed significantly increased expression in both purified and un-purified FL samples, indicating that despite frequently overexpressing BCL-2, FL appears to have increased basal level autophagy activity. 4 Expression of the key autophagy proteins p62, Beclin-1, LC3 and BCL-2 were determined in FL and DLBCL using tissue microarrays and immunohistochemistry. Both p62 and LC3, substrates of autophagic degradation, served as markers for autophagy activity. Significantly decreased expression of p62 and LC3, indicating active autophagy, was observed in FL samples (n=117). DLBCL samples (n=109) showed a heterogeneous expression pattern of these four proteins. We identified p62 as an independent prognostic biomarker in DLBCL with decreased expression predicting shorter overall, disease specific and progression-free survival. DLBCL patients with lower p62 or LC3 expression and higher levels of BCL-2, i.e. active autophagy and inhibited apoptosis, had the worst prognosis. Beclin-1 expression was significantly reduced in both FL and DLBCL, where lower levels were significantly associated with shorter overall and disease-specific survival. In summary, this study demonstrates that FL, characterised by overexpression of BCL-2, shows increased autophagy activity, indicating that BCL-2 may not inhibit basal level autophagy in this indolent lymphoma. High levels of BCL-2 and active autophagy did not affect the clinical outcome of FL, but significantly shortened the survival rates of DLBCL patients. Our data propose that active autophagy could be used as a biomarker for DLBCL prognosis, but not FL.

Lei Ieng Kit Kenny. / "April 2002." / Thesis (M.D.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (p. 89-118). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web.

Abstract unavailable.

Mantle cell lymphoma (MCL) is characterized by the presence of the t(11 ;14)(g13 ;g32) translocation which results in cyclin Dl over-expression. MCL is one of the most difficult lymphoproliferative disorders to manage with a median survival rate of 43 months from diagnosis. The poor prognosis associated with MCL is due in large part to its late classification as a separate clinical entity leading to a dearth in available pre-clinical models. The specific objectives of the research described in this thesis were (1) to establish MCL preclinical models of disease and (2) to evaluate deregulated cell signaling pathways in MCL that can impact treatment response. Pre-clinical models of MCL were established from pre-existing cell lines containing the t(11 ;14)(g13 ;g32). These cell lines were previously misclassified because they were developed prior to the classification of MCL as a distinct lymphoma subtype. With the establishment of MCL models, deregulated cell signaling pathways in MCL and response to different treatment strategies were investigated. These included an investigation of the cell signaling pathways activated in bcl-2 over-expressing MCL cells that were treated with oblimersen; a molecular gene silencing strategy that effectively suppresses bcl-2 in vitro and in vivo. Silencing bcl-2 provided insight into which pathways were influenced by bcl-2 over-expression in MCL. More specifically loss of cyclin D1, NF-KB, p53, bax and p27 were observed following bcl-2 silencing. Additional studies investigated how abnormal expression of CD40/CD40L and Fas/FasL along with bcl-2 family members contributes to B cell clonal expansion and influences Rituximab-mediated cell death in MCL models. Rituximab is a chimeric monoclonal antibody targeted against B cells and both Rituximab-sensitive and insensitive MCL models were defined. An abnormally high expression of bcl-2, bcl-x L, mcl-1, CD40/CD40L and Fas were observed in all MCL cells, as well as high levels of soluble FasL, capable of blocking Fas-mediated apoptosis. These deregulated pathways were associated with response to Rituximab treatment in a sensitive MCL model. These studies demonstrated some of the key pathways associated with treatment response in MCL, and the establishment of well characterized MCL models enables us to continue to explore new treatment strategies currently being studied in other lymphomas.

Mantle cell lymphoma (MCL) is characterized by the presence of the t(11 ;14)(g13 ;g32) translocation which results in cyclin Dl over-expression. MCL is one of the most difficult lymphoproliferative disorders to manage with a median survival rate of 43 months from diagnosis. The poor prognosis associated with MCL is due in large part to its late classification as a separate clinical entity leading to a dearth in available pre-clinical models. The specific objectives of the research described in this thesis were (1) to establish MCL preclinical models of disease and (2) to evaluate deregulated cell signaling pathways in MCL that can impact treatment response. Pre-clinical models of MCL were established from pre-existing cell lines containing the t(11 ;14)(g13 ;g32). These cell lines were previously misclassified because they were developed prior to the classification of MCL as a distinct lymphoma subtype. With the establishment of MCL models, deregulated cell signaling pathways in MCL and response to different treatment strategies were investigated. These included an investigation of the cell signaling pathways activated in bcl-2 over-expressing MCL cells that were treated with oblimersen; a molecular gene silencing strategy that effectively suppresses bcl-2 in vitro and in vivo. Silencing bcl-2 provided insight into which pathways were influenced by bcl-2 over-expression in MCL. More specifically loss of cyclin D1, NF-KB, p53, bax and p27 were observed following bcl-2 silencing. Additional studies investigated how abnormal expression of CD40/CD40L and Fas/FasL along with bcl-2 family members contributes to B cell clonal expansion and influences Rituximab-mediated cell death in MCL models. Rituximab is a chimeric monoclonal antibody targeted against B cells and both Rituximab-sensitive and insensitive MCL models were defined. An abnormally high expression of bcl-2, bcl-x L, mcl-1, CD40/CD40L and Fas were observed in all MCL cells, as well as high levels of soluble FasL, capable of blocking Fas-mediated apoptosis. These deregulated pathways were associated with response to Rituximab treatment in a sensitive MCL model. These studies demonstrated some of the key pathways associated with treatment response in MCL, and the establishment of well characterized MCL models enables us to continue to explore new treatment strategies currently being studied in other lymphomas.

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2005. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 6 uppsatser.