Worksafe--innovative web technology for occupational risk prevention.
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Equipment Design↗
Biomedical subjects
A J Sasco
Publications and source records attributed to A J Sasco.
Survival after proton-beam irradiation of uveal melanomas.
PURPOSE: To evaluate the independent prognostic factors for survival, metastasis, local recurrence, and enucleation in patients who had undergone proton-beam therapy for posterior uveal melanomas. DESIGN: Interventional case series. METHODS: In this retrospective study, 224 consecutive incident cases were treated at the Biomedical Cyclotron Centre (Nice, France) from June 1991 to December 1997. Overall, metastasis-free, local recurrence-free, and enucleation-free survival rates were calculated according to the Kaplan-Meier method using the log-rank test. The multivariate prognostic analysis was performed using the Cox proportional hazards model. RESULTS: The 5-year overall survival rate was 78.1% (SE: 3.7%). A largest basal tumor diameter (LTD) below 10 mm and female sex were independently associated with a better prognosis. The 5-year metastasis-free survival rate was 75.6% (SE: 3.6%). Only an LTD above 10 mm and ciliary body involvement were independently associated with metastasis. Ten patients (4.5%) had a local recurrence, which was correlated with the risk of metastasis (P =.045). The 5-year enucleation-free survival rate was 69.6% (SE: 4.0%). Once again, an LTD below 10 mm and female sex were predictive of a better prognosis. CONCLUSION: Our results with proton-beam therapy correspond to those reported in the literature. This treatment strategy is safe and yields predictably good results. In addition to the two independent prognostic factors for survival and metastasis, namely LTD and ciliary body involvement, sex also had a significant impact in our case series, but the clinical relevance of this finding is unknown.
Adult↗
Tobacco smoking and cancer: a brief review of recent epidemiological evidence.
This report summarises the epidemiological evidence on the association between tobacco smoking and cancer, which was reviewed by an international group of scientists convened by IARC. Studies published since the 1986 IARC Monograph on "Tobacco smoking" provide sufficient evidence to establish a causal association between cigarette smoking and cancer of the nasal cavities and paranasal sinuses, nasopharynx, stomach, liver, kidney (renal cell carcinoma) and uterine cervix, and for adenocarcinoma of the oesophagus and myeloid leukaemia. These sites add to the previously established list of cancers causally associated with cigarette smoking, namely cancer of the lung, oral cavity, pharynx, larynx, oesophagus, pancreas, urinary bladder and renal pelvis. Other forms of tobacco smoking, such as cigars, pipes and bidis, also increase risk for cancer, including cancer of the lung and parts of the upper aerodigestive tract. A meta-analysis of over 50 studies on involuntary smoking among never smokers showed a consistent and statistically significant association between exposure to environmental tobacco smoke and lung cancer risk. Smoking is currently responsible for a third of all cancer deaths in many Western countries. It has been estimated that every other smoker will be killed by tobacco.
Humans↗
The epidemiology of neonatal tumours. Report of an international working group.
Neonatal tumours occur every 12,500-27,500 live births and comprise 2% of childhood malignancies, but there is little clarity as to their real prevalence, sites of origin and pathological nature as reported series vary. As an entity, neonatal tumours provide a unique window of opportunity to study tumours in which minimal environmental interference has occurred. The majority of tumours present with a mass at birth (e.g., teratomas, neuroblastomas, mesoblastic nephroma, fibromatosis), which are not infrequently identified on antenatal ultrasound. Histologically, teratoma and neuroblastoma remain the two main tumour types encountered with soft tissue sarcoma, renal tumours, CNS tumours and leukaemia being the next most common tumour types identified. Malignant tumours are uncommon in the neonatal period per se and benign tumours may have malignant potential. A particular problem exists in clinical classification, as histological features of malignancy do not always correlate with clinical behaviour. Benign tumours may also be life threatening because of their size and location. Other tumours may demonstrate local invasiveness, but no metastatic potential, and tumours that are clearly malignant may demonstrate unpredictable or uncertain behaviour. Screening programmes have brought more tumours to light, but do not appear to affect the overall prognosis. They may provide clues to the stage at which tumours develop in foetu. The aetiology of cancer in children is multifactorial and includes both genetic and environmental factors. The association between congenital abnormalities and tumours is well established (15% of neonatal tumours). Genetic defects are highly likely in neonatal tumours and include those with a high risk of malignancy (e.g., retinoblastoma), but also genetically determined syndromes with an increased risk of malignancy and complex genetic rearrangements. Tumours are mostly genetically related at a cellular level and factors influencing cellular maturation or apoptosis within the developing foetus may continue to operate in the neonatal period. Cytogenetics of neonatal neoplasms appear to differ from neoplasms in older children, thus possibly explaining some of the observed differences in clinical behaviour. Certain constitutional chromosome anomalies, however, specifically favour tumours occurring in the foetal and neonatal period. In support of this hypothesis, certain cytogenetic anomalies appear to be specific to neonates, and a number of examples are explored. Other environmental associations include ionizing radiation, drugs taken during pregnancy, infections, tumours in the mother and environmental exposure.
Female↗
Estimating the distribution of lag in the effect of short-term exposures and interventions: adaptation of a non-parametric regression spline model.
Information on the distribution of lag duration between exposure or intervention and the subsequent changes in risk can help in assessing the impact of exposure, predicting cost-effectiveness of intervention, and understanding the underlying biological mechanisms. Previous approaches focused more on optimizing the strength of the exposure-disease association than on directly estimating lag duration. We propose an alternative approach applicable to the analysis of the lagged effects of binary exposure variables. The density function of the distribution of lags is estimated based on flexible modelling of changes in hazard ratio of exposed versus unexposed subjects. The methodology is evaluated in a simulation study and is applied to the Framingham data to investigate the lagged effect of smoking cessation on coronary heart disease risk.
Biometry↗
Trends in tobacco smoking among adolescents in Lyon, France.
To provide information that may promote more effective cancer prevention, we identified factors associated with regular smoking among adolescents in Lyon, France. School grades where these factors began to influence regular smoking were also identified. Seven consecutive cross-sectional anonymous surveys were conducted in three public schools, beginning in grade 6ème (average age 11.5 years) in 1993 and ending in grade Terminale (average age 17.4 years) in 1999. All classes in each respective grade were surveyed, with 3650 completed questionnaires for all years combined. Prevalence of current regular smoking is presented according to school grade for 17 variables identified as significantly related to regular smoking in a multivariate logistic regression analysis. Important factors associated with regular smoking were identified as early as grade 6ème and included not viewing the taking care of one's health as important, not eating breakfast regularly, associating with groups where smoking occurs, having a best friend who smokes, and having a brother and/or sister who smokes. Not regularly reading was first associated with an increased risk of regular smoking in grade 5ème. Not living with both parents, alcohol drinking, episodes of drunkenness, illicit drug use, and sexual relationships were positively associated with regular smoking in the middle and later grades, when these questions were first asked. Not playing sports and not playing with computers were initially associated with an increased risk of regular smoking in grade 3ème.
Adolescent↗
[Evaluation of adherence to the regulations for declaration of notification of transfusion reactions with fever and chills. A study of the Association Inter-Régionale du Sud-Est d'Hémovigilance (AIRSEH)].
Febrile non-hemolytic transfusion reactions (FNHTR) are the most frequently reported acute adverse effects of blood products, and should be notified within 48 h according to the hemovigilance regulation. In order to study the conformity of these notifications and to search for factors associated with non-conformity, we retrospectively studied all FNHTR notified by voluntary centers of the AIRSEH group from 1st September 1994 to 31st December 1999. Seven hundred and sixty-one FNHTR were registered by 10 centers, most of them were benign (grade 1); 67.8% were non-conform. The non-conformity was associated with the number of biological investigations performed (median number, respectively, 4.24 and 2.94--P = 0.038--in non-conform and conform notifications--P = 0.038) in univariate analysis. Using a logistic regression model, center and severity were the only two factors significantly associated with non-conformity. Different center practices, and in particular the interface between the hospital and the blood bank, may be responsible for the effect center. Moreover, the non-conformity concerns first of all benign FNHTR. A stronger separation between alert and epidemiological surveillance is proposed in order to improve the notifications' conformity.
Adult↗
Cancer: the role of extracellular disease.
Invasive carcinoma originates from the epithelial cells lining the lumen of an organ. It is often preceded by metaplasia, dysplasia or carcinoma in situ. The purpose of this review is to suggest that this disease of the epithelium may be, in part, the result of underlying tissue-based disorganization. Human cancer is frequently associated with pre-existing tissue disease. For example, hepatocellular carcinoma usually occurs in patients with a macronodular cirrhotic liver. Most lung cancers arise among patients with chronic lung disease (bronchitis, emphysema, and chronic infection). Mechanical forces appear to play a major role in regulating normal and cancer cell growth. The loss of cell polarity by neoplastic cells, coupled to an otherwise normal growth rate is enough to explain the cancer star-shaped pattern. By changing the plane of cell division, tumor cells may escape physical constraints from surrounding cells and divide. Loss of cell polarity and the resulting cell proliferation appears to be a consequence of either tissue-based disorganization (chronic inflammation, fibrosis) or of direct carcinogenic insult. The multiple mutations frequently described in cancer may be, in part, secondary to physical stress and not primary events. Several animal and clinical trials have shown that tissue disruption (i.e. radiation-induced fibrosis or liver cirrhosis) can be successfully treated. It is possible that treatment targeted at tissue disruption would delay or reduce cancer incidence regardless of the precise biological mechanism of carcinogenesis.
Adult↗
[Epidemiology of uterine cancers].
Uterine cancers comprise 2 distinct pathological entities: cancer of the cervix and cancer of the corpus. They differ both in descriptive and etiologic epidemiology. Cervical cancer is more frequent in the developing world, is decreasing in terms of incidence and even more mortality in many countries and has essentially a viral etiology, being linked to human papilloma viruses. Cancer of the uterine corpus is more frequent in the developed world, is rather stable in terms of incidence and mostly has a hormonal etiology.
Adult↗
Aspects of intracranial and spinal tumors in patients with Down syndrome and report of a rapidly progressing Grade 2 astrocytoma.
BACKGROUND: Brain tumors in patients with Down syndrome (DS) rarely are reported, and their behavior is not well known. METHODS: The authors report on a male patient age 19 years who had DS with diffuse astrocytoma (World Health Organization Grade 2) that recurred twice despite treatment, leading to a glioblastoma and, finally, to death in just over 2 years. The literature on brain tumors in patients with DS is reviewed. RESULTS: Although brain neoplasms were suspected to be in excess in patients with DS, the authors found only 36 patients with brain neoplasms and 2 spinal tumors. An unusual distribution of histologic tumor types, with an over-representation of germ cell and mesenchymal tumors and a lack of embryonal tumors, was observed, in agreement with what is known currently about the tumor profile of patients with DS. CONCLUSIONS: Cerebral tumors in patients with DS have a specific distribution and may behave differently compared with the general population. These features may be related to the gene dosage effect of oncogenes, antioncogenes, and genes involved in cerebral development due to the supernumerary chromosome 21.
Adult↗
Cancer incidence and work place exposure among Swedish biomedical research personnel.
OBJECTIVE: This cohort study aimed to elucidate cancer occurrence in relation to occupational exposure to specific chemical, biological and physical agents among biomedical research laboratory personnel in Sweden. METHODS: Standardized incidence ratios (SIRs) for the period 1970-1994 were calculated for specific exposures in the laboratory group (n = 3,277) and for personnel working in non-laboratory departments (n = 2,011), as an internal reference group. Expected numbers were based on national cancer rates. RESULTS: The total number of cancer cases was lower than expected in both laboratory and non-laboratory personnel. Elevated SIRs were noted for malignant melanoma among female laboratory employees for whom use was reported of solvents (SIR 2.73; CI 1.10-5.63) and of selected carcinogenic (International Agency for Research on Cancer (IARC) group 2B) agents (SIR 3.15; CI 1.16-6.85). A light increase of the risk estimate for breast cancer was also observed. CONCLUSIONS: In general, there were few cases of cancer in this comparatively young cohort, but the findings give some indication of increased risks for malignant melanoma in female laboratory personnel after exposure to organic solvents or substances classified by IARC as being possibly carcinogenic.
Breast Neoplasms↗
Epidemiology of breast cancer: an environmental disease?
Breast cancer is the leading cancer site in women, both in the developed and the developing world. Incidence rates are increasing in many countries, although, in some, mortality may be stable or slightly decreasing. Geographical differences exist, with high rates of disease in North America, North Europe and Oceania, intermediate rates in South and Central America as well as South and East Europe, and low rates in Africa and Asia. Most of the literature reports that genetic inherited factors account for less than 5% of cases, although some authors advance higher figures, up to about 10%. Risk factors for breast cancer are related to the reproductive life of women: early menarche, nulliparity or late age at first birth, late menopause, diet and physical exercise, as well as hormonal factors, be they endogenous (high levels of free or not bound to SHBG estrogens) or exogenous (long-term use of oral contraceptives or menopausal hormone replacement). The present review does not aim to be exhaustive and fully comprehensive, or to present in detail domains currently well known and accepted by all. On the contrary, it modestly wishes to highlight potentially controversial conditions which could in the future be recognized as new risk factors.
Africa↗
An infant with Down syndrome and retinoblastoma. A possible non-fortuitous association.
AIM: To evaluate the association between Down syndrome and retinoblastoma. METHOD: Presentation of a case report and review of the literature. RESULTS: A retinoblastoma was observed in a 10-month-old boy with Down syndrome. A review of the literature yielded 14 other cases, suggesting a possible excess of retinoblastoma in Down syndrome, as previously proposed by two epidemiological studies. The possible roles of external physical agents and hyperplastic and dysplastic lesions of the retina in subjects with Down syndrome is discussed. CONCLUSION: A positive association between Down syndrome and retinoblastoma is possible. An epidemiological study on this subject is needed to better ascertain this potential link.
Child↗
Quality assessment of cervical screening: a population-based case-control study in the C te-D'Or region, France.
Our objectives were to evaluate the effectiveness of cervical cancer screening outside organized programs in the prevention of cervical carcinoma in situ (CIS) and to enhance the way in which case control studies avoid some common biases. In our case-control study, we assessed all incident, histologically verified cases of CIS registered from 1987 to 1997 in the population-based cancer registry of C te-d'Or, France (N = 104) and 208 controls randomly selected from the screened population and matched for age, date of last screening, residence, and pathology laboratory results. We considered as appropriate for controls screened women who had had at least one Papanicolaou smear in the 3 years preceding the diagnosis or similar period. Screening for controls was higher (67.8%) than for cases (41.4%; P < .001), with a relative protection against CIS of 3.09 (95% confidence interval, 1.83-5.22) and a prevented fraction in the screened population of 45% to 50%. These findings suggest a protective advantage for CIS even in the absence of organized screening. The methodologic approach has advantages as compared to previous types of case-control studies. Although further refinements still are warranted, learning about the protective effect of screening for CIS provides information that may be useful in assessing the impact of a screening policy on women actually at risk of invasive cervical cancer.
Carcinoma in Situ↗
[Screening for cancer: from guidelines to practice].
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Age Factors↗
[Breast cancer in women with trisomy 21].
The population with Down's syndrome has a different cancer profile compared to the general population, even after taking into account issues of survival and ageing. Several solid tumours are unusually rare, whereas in contrast leukaemias are increased. In addition, few studies are available on this topic. We therefore decided to conduct a mortality study based on the INSERM national mortality statistics in France comparing over a 24 year period deaths from female breast cancer in the general French population with the cancer deaths in women with Down's syndrome. Only 5 deaths with Down's syndrome could be found compared to 68.98 expected based on national statistics. This clear reduction in risk agrees with other studies available in Down's syndrome patients. This observation could be partly explained by over expression of genes linked to gene dosage effects on chromosome 21, playing a role in cell growth, differentiation, survival and death. An additional protective effect could come from the marked and continued decreased exposure to oestrogens, starting in utero for women with trisomy 21 and lasting all over life.
Adolescent↗
Cancer risk in laboratory workers: an emphasis on biological research.
BACKGROUND: At the end of the 1980s, several cancer clusters were observed in biological research laboratories. Over time, biological research and the technologies used have been diverse and have involved a wide range of mutagenic or carcinogenic chemical, physical and biological agents. METHODS: We reviewed 45 published studies on cancer risk among biological research personnel and workers in closely related fields, and numerous reports based on routinely collected data. RESULTS: Biological research could be associated with an elevated risk for pancreatic cancer, brain tumors, and certain hemopathies. A common limitation of available studies was low statistical power and the absence or inaccuracy of data on individual past exposure. CONCLUSIONS: Overall, this study suggests a low overall risk of cancer, albeit a higher risk may be suggested for cancers of the pancreas (risk ratios ranging from 0.5 to 6.3) and brain (0.7-9.4), and for non-Hodgkin's lymphoma (0.6-51.5). We suggest ways in which multiple past exposures could be assessed more precisely and emphasize a pressing need to take into account known confounders.
Biological Science Disciplines↗
A retrospective evaluation of the causes of death of 448 insured French horses in 1995.
Epidemiological studies should allow comparisons to be made of the prevalence of disease in populations from different countries, but the population characteristics and health problems in French horses are not well established. We have conducted a retrospective evaluation of the causes of death and vital characteristics of insured horses in France for the year 1995, with a view to comparison with published data from other countries. Files on 448 deceased horses were provided by nine insurance companies. Most of the animals were used for breeding (60%), followed by leisure (20%), eventing and racing (10% each). Physical characteristics were associated significantly with occupational categories. The overall mortality rate was 2.47%, and was due, in decreasing order, to foaling (24%), colic (21%) or locomotor (21%), cardiovascular (9%), neurological (8%), respiratory (5%) or infectious (4%) disease. Infectious disease was more frequent in younger animals (p < 0.05) and locomotor disease in racehorses (p < 0.01). Horses aged over 15 years had a lower incidence of colic (p <0.05). The cause of death was not significantly linked to breed, insurance value or season. Despite some selection bias, the study provides useful information about mortality in the French equine population.
Animals↗