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The British Journal of Ophthalmology Nov 2010The survival of retinoblastoma in less-developed countries (LDCs) and the impact of socioeconomic variables on survival are not widely available in the literature. (Review)
Review
BACKGROUND
The survival of retinoblastoma in less-developed countries (LDCs) and the impact of socioeconomic variables on survival are not widely available in the literature.
METHODS
A systematic review of publications from LDCs was performed. Articles were from multiple databases and written in seven languages. Results were correlated with socioeconomic indicators. Lower-income countries (LICs) and middle-income countries (MICs) were included in our analyses.
RESULTS
An analysis of 164 publications including 14,800 patients from 48 LDCs was performed. Twenty-six per cent of the papers were written in languages other than English. Estimated survival in LICs was 40% (range, 23-70%); in lower MICs, 77% (range, 60-92%) and in upper MICs, 79% (range, 54-93%; p = 0.001).Significant differences were also found in the occurrence of metastasis: in LICs, 32% (range, 12-45); in lower MICs, 12% (range, 3-31) and in upper MICs, 9.5% (range, 3-24; p = 0.04). On multivariate analysis, physician density and human development index were significantly associated with survival and metastasis. Maternal mortality rate and per capita health expenditure were significantly associated with treatment refusal.
CONCLUSIONS
Important information from LDCs is not always available in English or in major databases. Indicators of socioeconomic development and maternal and infant health were related with outcome.
Topics: Adolescent; Child; Child, Preschool; Developing Countries; Humans; Infant; Retinoblastoma; Socioeconomic Factors; Survival Rate
PubMed: 20733021
DOI: 10.1136/bjo.2009.168062 -
British Journal of Cancer Dec 2009Low cancer awareness contributes to delay in presentation for cancer symptoms and may lead to delay in cancer diagnosis. The aim of this study was to review the evidence... (Review)
Review
BACKGROUND
Low cancer awareness contributes to delay in presentation for cancer symptoms and may lead to delay in cancer diagnosis. The aim of this study was to review the evidence for the effectiveness of interventions to raise cancer awareness and promote early presentation in cancer to inform policy and future research.
METHODS
We searched bibliographic databases and reference lists for randomised controlled trials of interventions delivered to individuals, and controlled or uncontrolled studies of interventions delivered to communities.
RESULTS
We found some evidence that interventions delivered to individuals modestly increase cancer awareness in the short term and insufficient evidence that they promote early presentation. We found limited evidence that public education campaigns reduce stage at presentation of breast cancer, malignant melanoma and retinoblastoma.
CONCLUSIONS
Interventions delivered to individuals may increase cancer awareness. Interventions delivered to communities may promote cancer awareness and early presentation, although the evidence is limited.
Topics: Early Detection of Cancer; Health Education; Health Knowledge, Attitudes, Practice; Humans; Neoplasms; Randomized Controlled Trials as Topic
PubMed: 19956160
DOI: 10.1038/sj.bjc.6605388 -
Medical Science Monitor : International... Dec 2008Retinoblastoma (Rb) is the most common primary malignant intraocular tumour in childhood. The "two hit" theory, formulated by Knudson in 1971 to explain the variegated... (Review)
Review
BACKGROUND
Retinoblastoma (Rb) is the most common primary malignant intraocular tumour in childhood. The "two hit" theory, formulated by Knudson in 1971 to explain the variegated clinical expression of the disease, led to the discovery of the so called tumour suppressor genes and the identification of the Rb1 as the prototype of such genes. Mutations of the Rb1 gene are now commonly believed to be the "cause" retinoblastoma, although epidemiological, clinical, and biological evidences argue against it.
MATERIAL/METHODS
The Authors have performed a systematic review of available data concerning clinical and diagnostic aspects of retinoblastoma, including molecular genetics. Meta analysis of literature data has been performed in order to validate some of the predictions made by the two hit theory.
RESULTS
The following theses are discussed in detail: 1) there is no difference in the age at diagnosis between unilateral and bilateral retinoblastoma; 2) the pathogenetic mechanisms underlying familial, hereditary, and sporadic retinoblastoma are different; 3) bilateral retinoblastoma is not necessarily hereditary; 4) The real incidence of the unilateral phenotype within the familial group is disproportionately higher than that predicted by the "two hit"; 5) retinoblastoma is most probably "caused" by the combination of epigenetic factors and aneuploidy.
CONCLUSIONS
Epidemiological, clinical, and more recent biological and genetic evidences, show that the "two hit" theory represents a rather simplistic, outdated, and unreliable model to explain tumour development and clinical evolution of retinoblastoma.
Topics: Age Factors; Humans; Infant; Mutation; Retinoblastoma
PubMed: 19043380
DOI: No ID Found -
International Journal of Technology... 2006The aim of this study was to conduct a systematic review of the evidence for treatments for retinoblastoma in children. (Review)
Review
OBJECTIVES
The aim of this study was to conduct a systematic review of the evidence for treatments for retinoblastoma in children.
METHODS
Seventeen electronic databases were searched. Two reviewers independently selected studies. Studies of participants diagnosed with childhood retinoblastoma, any interventions, and all clinical outcomes were eligible. Randomized and nonrandomized controlled trials and cohort studies with clear comparisons between treatment groups were included. Methodological quality was assessed.
RESULTS
Thirty-one observational comparative studies were included, of which twenty-seven were retrospective. The methodological quality was generally poor, with a high risk of selection bias in all studies. Although there were high levels of treatment success in many of the studies, due to the limitations of the evidence identified, it was not possible to make meaningful and robust conclusions about the relative effectiveness of different treatment approaches for retinoblastoma in children.
CONCLUSIONS
Good quality randomized controlled trials are required. Where controlled trials are not feasible, only high quality prospective, nonrandomized studies should be given consideration, due to the generally higher risk of bias in retrospective studies.
Topics: Child; Evidence-Based Medicine; Humans; Randomized Controlled Trials as Topic; Retinoblastoma; Retrospective Studies; Technology Assessment, Biomedical; Treatment Outcome
PubMed: 16984673
DOI: 10.1017/S0266462306051324 -
International Journal of Technology... 2006The Human Genome Project has led to a multitude of new potential screening targets on the level of human DNA. The aim of this systematic review is to critically... (Review)
Review
OBJECTIVES
The Human Genome Project has led to a multitude of new potential screening targets on the level of human DNA. The aim of this systematic review is to critically summarize the evidence from health economic evaluations of genetic screening in the literature.
METHODS
Based on an extensive explorative search, an appropriate algorithm for a systematic database search was developed. Twenty-one health economic evaluations were identified and appraised using published quality criteria.
RESULTS
Genetic screening for eight conditions has been found to be investigated by health economic evaluation: hereditary breast and ovarian cancer, familial adenomatous polyposis (FAP) colorectal cancer, hereditary nonpolyposis colorectal carcinoma (HNPCC), retinoblastoma, familial hypercholesterolemia, hereditary hemochromatosis, insulin-dependent diabetes mellitus, and cystic fibrosis. Results range from dominated to cost-saving. Population-wide genetic screening may be considered cost-effective with limited quality of evidence only for three conditions. The methodology of the studies was of varying quality. Cost-effectiveness was primarily influenced by mutation prevalence, genetic test costs, mortality risk, effectiveness of treatment, age at screening, and discount rate.
CONCLUSIONS
Health economic evidence on genetic screening is limited: Only few conditions have properly been evaluated. Based on the existing evidence, healthcare decision makers should consider the introduction of selective genetic screening for FAP and HNPCC. As genetic test costs are declining, the existing evaluations may warrant updating. Especially in the case of hereditary hemochromatosis, genetic population screening may be about to turn from a dominated to a cost-effective or even cost-saving intervention.
Topics: Costs and Cost Analysis; Genetic Diseases, Inborn; Genetic Predisposition to Disease; Genetic Testing; Humans; Metabolic Diseases; Neoplasms; Respiratory Tract Diseases; Technology Assessment, Biomedical
PubMed: 16984061
DOI: 10.1017/s0266462306051221 -
Health Technology Assessment... Dec 2005To assess the clinical effectiveness of treatments for childhood retinoblastoma. (Review)
Review
OBJECTIVES
To assess the clinical effectiveness of treatments for childhood retinoblastoma.
DATA SOURCES
Electronic databases were searched from inception to April 2004.
REVIEW METHODS
Studies of participants diagnosed with childhood retinoblastoma, any interventions and all clinical outcomes were eligible for inclusion. Randomised and non-randomised controlled trials and cohort studies with clear comparisons between treatment groups were included. Methodological quality was assessed. A narrative synthesis was conducted. Where possible, studies assessing common interventions were grouped together, with prospective and retrospective studies grouped separately. Emphasis was placed on prospective studies.
RESULTS
Thirty-one individual studies, from 42 publications, were included in the review. Apart from one non-randomised controlled trial, only comparative studies of observational design were available for any of the treatments. Four of the included studies were prospective and the remaining 27 were retrospective. Most of the studies were of radiotherapy or chemotherapy, with few studies available on enucleation or focal treatments such as brachytherapy, photocoagulation, cryotherapy and thermotherapy. The methodological quality was generally poor, with a high risk of bias in all included studies. The main problems were in relation to how treatment was allocated and lack of consideration of potentially confounding factors, such as initial disease severity, in the study design and data analysis. The evidence base for effectiveness of treatments for childhood retinoblastoma is extremely limited. Owing to the considerable limitations of the evidence identified, it was not possible to make meaningful and robust conclusions about the relative effectiveness of different treatment approaches for childhood retinoblastoma.
CONCLUSIONS
In the authors' opinion, the evidence base for the effectiveness of treatments for childhood retinoblastoma is not sufficiently robust to provide clear guidance for clinical practice. Ideally, good-quality randomised controlled trials (RCTs) assessing the effectiveness of different treatment options for childhood retinoblastoma are required. Research is required on all the treatments currently used for this condition. Where RCTs are not feasible, for ethical or practical reasons, only high-quality, prospective, non-randomised studies should be given consideration, owing to the generally higher risk of bias in retrospective studies. To reduce the risk of confounding due to allocation by clinical indication, studies should compare patients with similar disease severity rather than compare patients of mixed disease severities. Standardised outcomes should be agreed for use in studies assessing the effectiveness of treatment. These outcomes should encompass potential important adverse effects of treatment such as loss of visual acuity and cosmetic outcome, as well as beneficial effects.
Topics: Adolescent; Child; Child, Preschool; Humans; Infant; Infant, Newborn; Outcome Assessment, Health Care; Prognosis; Retinal Neoplasms; Retinoblastoma
PubMed: 16336843
DOI: 10.3310/hta9480 -
Anales de Pediatria (Barcelona, Spain :... Dec 2005Cancer is the result of the interaction of two kinds of determinants: genetic (endogenous) and environmental (exogenous). In the last few decades, pediatric oncology as... (Review)
Review
INTRODUCTION
Cancer is the result of the interaction of two kinds of determinants: genetic (endogenous) and environmental (exogenous). In the last few decades, pediatric oncology as a whole has progressed, including knowledge of malignant osseous tumors (MOT). Although advances have been made in diagnostic and therapeutic aspects, little progress has taken place in our knowledge of the risk factors involved in their etiopathogenesis.
OBJECTIVE
This review has three objectives: a) to provide an update on MOT-related risk factors in the child and adult population; b) to disseminate knowledge of the main MOT-related risk factors among our colleagues in order to promote research into these factors, diagnosis and future prevention, and c) to request help from our colleagues in the Environment and Pediatric Cancer research project.
MATERIAL AND METHODS
We performed a systematic review of the literature published in the last 30 years on risk factors implicated in the etiopathogenesis of MOT, using Medline, Cancerlit, Science Citation Index and Embase. The search profiles used were: pediatric/childhood malignant bone tumors, pediatric/ childhood bone cancer/neoplasm, osteosarcoma/bone sarcoma/Ewing's sarcoma and risk factors/etiology/epidemiology. The most interesting articles were selected and the most relevant references contained therein were retrieved.
RESULTS
MOT represent 6-7 % of all pediatric neoplasms. The most frequent types are osteosarcoma (OS) and Ewing's sarcoma (ES), representing 56 % and 34 % respectively. OS-related risk factors are the following: a) previous osseous disease (Paget's disease); b) familial-genetic factors (hereditary retinoblastoma, Li-Fraumeni syndrome, Rothmund-Thompson syndrome, Bloom syndrome, familial OS, Diamond-Blackfan anemia); c) chemical factors (antineoplastic drugs); d) physical factors (ionizing radiation); e) biologic factors; f) parental occupation, and g) other factors (artificial osseous implants and traumatisms). ES-related risk factors are the following: a) ethnic-cultural (Caucasian race); b) genetic factors; c) parental occupation (herbicide, pesticide and fertilizer exposure); d) maternal obstetric history, and e) other factors (parental smoking and inguinal hernia).
CONCLUSIONS
Most causes of MOT are unknown. Based on different levels of scientific evidence, the main factors implicated in the etiopathogenesis of OS are: Paget's disease, hereditary retinoblastoma, Li-Fraumeni syndrome, antineoplastic drugs, and ionizing radiation. The main factors related to ES are: Caucasian race, parental occupation, parental smoking, and surgery for inguinal hernia. The main obstacles to greater knowledge of MOT-related factors are: a) their multiple origin; b) the low prevalence in the population; c) lack of environmental health training in pediatrics, and d) the low public and private investment in this research field.
Topics: Adolescent; Adult; Bone Neoplasms; Child; Child, Preschool; Humans; Infant; Osteosarcoma; Risk Factors; Sarcoma, Ewing
PubMed: 16324620
DOI: 10.1016/s1695-4033(05)70254-x -
Ophthalmology Oct 2003To assess the risk of retinoblastoma developing in children with microscopic chromosomal with mosaic deletions involving 13q14. (Review)
Review
PURPOSE
To assess the risk of retinoblastoma developing in children with microscopic chromosomal with mosaic deletions involving 13q14.
DESIGN
Case report and systematic literature review.
PARTICIPANTS
Data on 29 patients with a mosaic and 107 patients with a nonmosaic somatic deletion of chromosome 13q14 were compared.
MAIN OUTCOME MEASURES
Age at diagnosis, frequency, and laterality of retinoblastoma.
CASE REPORT
A dysmorphic baby, who carried a chromosomal deletion involving 13q14 in 34% of peripheral blood lymphocytes, had neuroradiologic evidence of retinoblastoma at the age of 2 weeks. She developed trilateral retinoblastoma, a pineal neuroblastic tumor, at the age of 10 months. The diagnosis of her tumor was delayed because of misjudgment of risk of retinoblastoma developing.
RESULTS
Meta-analysis revealed no difference between children with mosaic and nonmosaic chromosomal deletion of 13q14 regarding the age at diagnosis, laterality of tumor, and presence of family history for retinoblastoma. A lower percentage of somatic cells with mosaic deletion did not predict a higher age at diagnosis or unilateral tumors. No statistically significant difference was noted regarding the presence of mental retardation, dysmorphic features, and anomalies of internal organs between mosaic and nonmosaic deletions. Only 7% (95% confidence interval, 1-23) of 29 patients who had a mosaic chromosomal deletion including 13q14 were not reported to develop retinoblastoma.
CONCLUSIONS
Whenever a 13q14 deletion is diagnosed, immediate ophthalmologic evaluation is recommended to ensure prompt diagnosis of retinoblastoma. Mosaic and nonmosaic chromosomal deletions of 13q14 do not differ regarding the risk and type of retinoblastoma developing.
Topics: Brain Neoplasms; Chromosome Deletion; Chromosomes, Human, Pair 13; Fatal Outcome; Female; Humans; Infant; Magnetic Resonance Imaging; Mosaicism; Pineal Gland; Pinealoma; Retinal Neoplasms; Retinoblastoma; Risk Factors; Tomography, X-Ray Computed
PubMed: 14522775
DOI: 10.1016/S0161-6420(03)00484-6 -
Ophthalmology Jun 2001To analyze the association between retinoblastoma (Rb) and sebaceous carcinoma (SC) of the eyelid to improve surveillance of survivors of RB: (Review)
Review
OBJECTIVE
To analyze the association between retinoblastoma (Rb) and sebaceous carcinoma (SC) of the eyelid to improve surveillance of survivors of RB:
DESIGN
Case report and systematic literature review.
METHODS
Ten patients who had SC develop after Rb were identified by systematic literature review, and a child who died with lymph node, lung, and liver metastases 7 years after irradiation for Rb is described. The data were analyzed by univariate statistics, including cumulative frequency distribution plots and Kaplan-Meier analysis.
RESULTS
Of 11 children with SC of the eyelid who all had hereditary RB, 9 (82%; 95% confidence interval, 48-98) received a median of 46 Gy (range, 21-89) of radiotherapy at a median age of 16 months (range, 0.5-15 years) and had SC develop within the field of radiation. Their median age at diagnosis of SC was 14 years (range, 8-30 years), median diagnostic delay 12 months (range, 6 months-3 years), and median interval from irradiation 11 years (range, 5-26 years); 7 of them (78%; 95% confidence interval, 40-97) were diagnosed between 5 and 15 years after radiotherapy. SC also developed at the age of 32 and 54 years in two nonirradiated Rb patients. Five patients had regional lymph node metastases after a median time of 12 months (range, 1 month-24 years). The 5-year cumulative probability of survival was 87%.
CONCLUSIONS
SC of the eyelid may occur in patients with hereditary Rb regardless of primary treatment, especially within the field 5 to 15 years after radiotherapy.
Topics: Adenocarcinoma, Sebaceous; Eyelid Neoplasms; Fatal Outcome; Humans; Infant; Lymphatic Metastasis; Male; Retinal Neoplasms; Retinoblastoma
PubMed: 11382640
DOI: 10.1016/s0161-6420(01)00555-3 -
Journal of Clinical Oncology : Official... Jun 1999To obtain refined knowledge regarding trilateral retinoblastoma (TRb), which is a syndrome that consists of hereditary retinoblastoma associated with an intracranial... (Meta-Analysis)
Meta-Analysis
PURPOSE
To obtain refined knowledge regarding trilateral retinoblastoma (TRb), which is a syndrome that consists of hereditary retinoblastoma associated with an intracranial neuroblastic tumor.
MATERIALS AND METHODS
Using a systematic literature review, we contacted authors to obtain missing information. Data from 106 children were used in a meta-analysis including frequency distributions and Kaplan-Meier survival curves.
RESULTS
TRb showed no sex predilection. Median age at diagnosis of retinoblastoma was 5 months (range, 0 to 29 months); age at diagnosis was younger among 47 children (47%) with familial retinoblastoma compared with age at diagnosis among 52 children (53%) with sporadic retinoblastoma (2 v 6.5 months, P <.0001). TRb usually affected the second or third generation with retinoblastoma. Median time from retinoblastoma to TRb was 21 months (range, 6 months before to 141 months after); time to TRb was longer for 78 (77%) pineal tumors compared with 23 (23%) suprasellar tumors (32 v 6.5 months, P <.0001). The size (27 v 32 mm, P =.57) and prognosis (survival of 9 v 8 months, P =.91) of pineal and suprasellar tumors were similar. TRb was detected earlier (1 v 22 months, P =.0007) and the child survived longer if neuroimaging was routinely performed (16 v 8 months, P =.001), but age at death was similar (36 v 37 months, P =.98). Cumulative 5-year survival (which was likely to indicate cure) was 27% (v 0%) if screening was undertaken. All children whose TRb exceeded 15 mm in size died.
CONCLUSION
The family history, age at diagnosis, and laterality of retinoblastoma in children with TRb resembled that of ordinary hereditary retinoblastoma. Suprasellar TRb were diagnosed earlier, and may arise earlier, than pineal TRb. Screening by neuroimaging could improve the cure rate if cases of TRb were detected when tumors were 15 mm or smaller in size.
Topics: Age of Onset; Brain Neoplasms; Child; Child, Preschool; Female; Genetic Predisposition to Disease; Humans; Infant; Male; Retinal Neoplasms; Retinoblastoma; Sex Distribution; Survival Rate
PubMed: 10561222
DOI: 10.1200/JCO.1999.17.6.1829