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Retinoblastoma in South Africa. A 20-year retrospective study at two tertiary academic hospital in JohannesburgGoolam, Saadiah 22 April 2015 (has links)
A dissertation submitted to the Faculty of Health Sciences, University of the
Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree
of Master of Medicine in Ophthalmology
Johannesburg, 2014 / Retinoblastoma is the most frequent malignant intraocular tumour of
childhood, and in Africa it is the commonest and most important life
threatening ocular neoplasm. In resource-rich countries such as the United
States and Canada, survival rates for patients with retinoblastoma approach
100%. This is in stark contrast to developing countries where survival rates
may be less that 20%. Despite the vast majority of affected patients living in
less developed countries, there is little attention and published literature on
disease characteristics in these populations.
OBJECTIVES: To characterise retinoblastoma in the South African population
through a 20-year retrospective analysis of patient records at two tertiary
academic hospitals in Johannesburg.
DESIGN AND METHOD: Retrospective clinical case series analysis of
medical records of patients with retinoblastoma presenting to Charlotte
Maxeke Johannesburg Academic Hospital and Chris Hani Baragwanath
Academic Hospital between 01 January 1992 and 31 December 2011.
RESULTS: The total number of retinoblastoma cases identified was 282, with
245 of these meeting the study inclusion criteria. Retinoblastoma comprised
6.9% of total paediatric oncology presentations. 65.3% were unilateral, 34.3%
bilateral and 0.4% trilateral. The overall male to female ratio was 1.08. Mean
age at presentation overall was 32.6 months (median 28.0 months), for
unilateral 39.4 months (median 33.0 months) and for bilateral 19.7 months
(median 17.0 months). The mean delay to presentation overall was 7.0
months (median 4.0 months), for unilateral 8.5 months (median 5.0 months)
and for bilateral 4.4 months (median 3.0 months). The most frequent
presenting symptoms were leukocoria (37.1%) and proptosis (34.7%).
Distribution of disease stage at presentation (using the International
Retinoblastoma Staging System) was 1.6% with Stage 0, 24.1% with Stage I,
27.8% Stage II, 16.3% Stage III and 25.3% Stage IV (data not available in
4.9%). 26.5% of patients defaulted care. The five-year survival rate was
57.7% in the overall study population, and according to disease stage at
presentation: 95.3% - Stage I, 84.8% - Stage II, 49.7% - Stage III and 5.7% -
Stage IV.
CONCLUSION: The five-year survival rate for Stage I disease is similar to the
overall five-year survival rates reported in the developed world. This suggests
that treatment standards at the study hospitals are comparable with those of
developed countries and that similar overall survival rates may be achieved if
patients were to present as early. Delay to presentation, disease stage at
presentation and defaulting care were identified as key factors contributing to
the poor overall survival rate. This study provides information regarding
patient demographics, social challenges in management, and patient
outcomes in comparison to developed countries and to reports from other
African populations. It also highlights the need for educational campaigns and
screening initiatives to address poor survival outcomes as a result of late
presentation and high rates of patients defaulting care. Finally, this report
serves as a platform for comparison with future research in this area.
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GENOMIC CHARACTERIZATION OF RECURRENT CHROMOSOMAL ABERRATIONS IN RETINOBLASTOMAD'Silva, Crystal 19 October 2010 (has links)
Retinoblastoma is the second most common childhood intraocular malignancy and development of the tumour is initiated by bi-allelic loss of the RB1 gene. Bi-allelic RB1 loss may not always directly lead to malignant retinoblastoma. Subsequent mutational events, specifically gain and loss of chromosomal regions harbouring key oncogenes and tumour suppressor genes, appear to underlie the progression of precursor lesions such as retinoma to retinoblastoma. Research thus far has implicated several cytogenetic aberrations in this sequence of molecular events, the two most recurrent and notable being the augmented copy number status of KIF14 and MDM4 on 1q and of DEK and E2F3 on 6p. A small subset of retinoblastoma exhibits high-level amplification of the MYCN gene on chromosome 2p and is characterized by pRb expression and aggressive histology. 1p36 deletion is also associated with MYCN amplification in neuroblastoma. Our project is testing the hypothesis that 1q and 6p gain and 2p amplification – defined by extra copies of KIF14 and MDM4, DEK and E2F3 and MYCN respectively, and 1p36 deletion – are biomarkers of retinoblastoma progression. This study reports the results of formalin-fixed paraffin-embedded fluorescence in situ hybridization (FFPE-FISH) analysis of the aforementioned genes in two pre-constructed tissue microarrays (TMAs) comprising 270 retinoblastoma patient tumours. Results show 1q gain (3-10 copies) in 136/262 (52%), 6p gain in 127/262 (48.7%), MYCN gain in 18/265 (6.8%) and MYCN amplification (>10 copies) in 20/265 (7.5%) patient tumours. MYCN amplification was also observed in a sample which retained pRb protein expression. Additionally we have demonstrated statistically significant associations between 1q and 6p gain and MYCN amplification and 1p36 deletion. The large cohort and consequent statistical power of our results has enabled a better understanding of the M3 to Mn sequence of genomic aberrations in the progression from retinoma to retinoblastoma. Statistically significant associations between 1q and 6p, indicates synergy within these two regions of gain that would be particularly beneficial to tumours. Owing to the biological interactions among the proteins encoded by DEK, E2F3, KIF14 and MDM4, tumour cells manifesting both 1q and 6p aberrations would have a selective survival and proliferative advantage. / Thesis (Master, Pathology & Molecular Medicine) -- Queen's University, 2010-10-18 16:59:40.965
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Immunoneurobiological studies of retinal ganglion neuronotrophic factor and its application in experimental treatment ofretinoblastoma任峰, Ren, Feng. January 1993 (has links)
published_or_final_version / Anatomy / Doctoral / Doctor of Philosophy
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Analysis of gene rearrangement and protein expression of the tumour suppressor genes RB and P16 in patients with acute myeloid leukaemia : possible roles in leukaemogenesis leukaemiaA. Jamal, A. Rahman Bin January 1996 (has links)
No description available.
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Investigation of the chromosome 13 band q14 lesions in B-cell chronic lymphocytic leukaemia : evidence for a novel tumour suppressor geneChapman, Robert Macdonald January 1996 (has links)
No description available.
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A Subset of Retinoblastoma Lacking RB1 Gene Mutations have High-level MYCN Gene AmplificationYee, Stephanie 29 July 2010 (has links)
Retinoblastoma is the prototype genetic cancer caused by mutations disrupting the RB1 tumor suppressor gene. Following loss of RB1, retinoblastoma acquires further genetic changes in a characteristic set of oncogenes and tumor suppressors including gains of the oncogenes KIF14, DEK, E2F3, and MYCN and loss of the tumor suppressor CDH11. The constellation of genetic changes is the postulated genetic pathway leading to retinoblastoma. However, advances in molecular diagnostic testing for RB1 gene mutations allows detection of at least one RB1 mutation in 98% of unilateral retinoblastomas leaving 2% of cases with undetectable RB1 mutations (RB1+/+ retinoblastoma). RB1+/+ retinoblastomas have high-level MYCN gene amplification (>30 copies) and few other genetic changes. In addition, RB1+/+ retinoblastoma present earlier than conventional RB1-/- retinoblastoma and show histologic features similar to MYCN-amplified neuroblastoma. Altogether, this study describes a distinct genetic subset of retinoblastoma characterized by wild-type RB1 gene and high-level MYCN gene amplification.
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A Subset of Retinoblastoma Lacking RB1 Gene Mutations have High-level MYCN Gene AmplificationYee, Stephanie 29 July 2010 (has links)
Retinoblastoma is the prototype genetic cancer caused by mutations disrupting the RB1 tumor suppressor gene. Following loss of RB1, retinoblastoma acquires further genetic changes in a characteristic set of oncogenes and tumor suppressors including gains of the oncogenes KIF14, DEK, E2F3, and MYCN and loss of the tumor suppressor CDH11. The constellation of genetic changes is the postulated genetic pathway leading to retinoblastoma. However, advances in molecular diagnostic testing for RB1 gene mutations allows detection of at least one RB1 mutation in 98% of unilateral retinoblastomas leaving 2% of cases with undetectable RB1 mutations (RB1+/+ retinoblastoma). RB1+/+ retinoblastomas have high-level MYCN gene amplification (>30 copies) and few other genetic changes. In addition, RB1+/+ retinoblastoma present earlier than conventional RB1-/- retinoblastoma and show histologic features similar to MYCN-amplified neuroblastoma. Altogether, this study describes a distinct genetic subset of retinoblastoma characterized by wild-type RB1 gene and high-level MYCN gene amplification.
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Immunoneurobiological studies of retinal ganglion neuronotrophic factor and its application in experimental treatment of retinoblastoma /Ren, Feng. January 1993 (has links)
Thesis (Ph. D.)--University of Hong Kong, 1994. / Includes list of author's publication (leaves viii-xiv). Includes bibliographical references (leaves 253-281).
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Molecular basis of cell cycle control : p300 and pRbChan, Ho Man January 2000 (has links)
No description available.
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Selective Intra-Ophthalmic Artery Chemotherapy for Advanced Intraocular Retinoblastoma: CCHMC Early ExperienceMichaels, Samantha T., M.D. January 2014 (has links)
No description available.
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