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Biomedical subjects

A J Sasco

Publications and source records attributed to A J Sasco.

At least 19 recordsLinked to original sources
PubMed2001

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↗
PubMed2001

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↗
PubMed2000

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↗
PubMed2000

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↗
PubMed2000

Endometrial mesodermal mixed tumor occurring after tamoxifen treatment: report on a new case and review of the literature.

BACKGROUND: Anti oestrogenic treatment is widely used for breast cancer treatment and prevention of recurrence. Because of concomitant estrogenic effects, tamoxifen exerts carcinogenic properties on the endometrium. Although secondary endometrial cancers usually present as pure adenocarcinomas, other types of rare tumors have also been reported. PATIENTS AND METHODS: Herein we describe the clinical, pathological as well as therapeutic aspects of a new case of endometrial mesodermal mixed tumor occurring after long-term tamoxifen therapy. RESULTS: The present case occured five years after cessation of a five years tamoxifen treatment. The patient failed to respond to doxorubicin and cyclophosphamide when combined to 5-fluorouracil (5-FU), but she reached complete response when the same two drugs were used with carboplatin, suggesting the potential usefullness of platinum derivatives. CONCLUSIONS: A longer latency period might be observed for endometrial mesodermal mixed tumors as compared to adenocarcinomas and could justify a prolonged clinical and ultrasonographic follow-up of patients during and after tamoxifen treatment. When indicated, chemotherapy might require the use of platinum derivatives in this particular type of secondary tumor.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

[Screening for cancer: what's new?].

Setting up of screening programmes for cancers has been the result of evaluation studies but even more of the existence (or non existence) of national policies for cancer control. We know for sure that mammographic screening can reduce breast cancer mortality in women from age 50 onwards, smear screening has a favourable impact on cervical cancer mortality and incidence, and faecal blood testing in stools may reduce colon cancer mortality. Other questions, considered for a long time as settled, are coming back, either because new data are available, such as in screening for breast cancer before age 50, or because new screening methods are being proposed, such as for lung cancer. Finally, the recognition of populations at very high genetic risk makes necessary the search for answers for example for familial breast and/or ovarian cancer. Last but not least is the methodological challenge: how can we rapidly provide answers, which implies the need for new approaches, in addition to randomized controlled trials?

Age Factors↗
PubMed2000

[Cannabis and cancer].

Several publications have recently suggested a relationship between cannabis use and certain types of cancer. We gathered information on the latest findings on the subject. A manual and computerized bibliographic search on cannabis and cancer was conducted. In users under 40 years of age, cannabis is suspected to increase the risk of squamous-cell carcinoma of the upper aerodigestive tract, particularly of the tongue and larynx, and possibly of lung. Other tumours being suspected are non-lymphoblastic acute leukaemia and astrocytoma. In head and neck cancer, carcinogenicity was observed for regular (i.e. more than once a day for years) cannabis smokers. Moreover, cannabis increases the risk of head and neck cancer in a dose-response manner for frequency and duration of use. Interaction was observed with cigarette smoking and alcohol use. Delta9-THC seems to have a specific carcinogenic effect different from that of the pyrolysis products. Epidemiological studies are needed as soon as possible to provide data on the European and French situation. Information on the possible risks of a regular use of cannabis should be a priority.

Adolescent↗
PubMed1999

Mortality and cancer incidence in biomedical laboratory personnel in Sweden.

BACKGROUND: The work in biomedical laboratories is associated with exposure to a mixture of known and potential chemical carcinogens, mutagens, and teratogens. Previous studies have suggested an excess of brain tumors and hematopoietic system malignancies as well as breast cancers in women. METHODS: This retrospective cohort study investigated the standardized mortality ratio (SMR) and the standardized incidence ratio (SIR) for cancer in biomedical research laboratory personnel in Swedish universities 1970-1992. The cohort comprised 5,035 laboratory and, as an internal reference group, 2,923 nonlaboratory employees. RESULTS: The overall death rate was lower in both groups than in the general population. The SIR for brain tumors among male laboratory workers was 1.69 (0.62-3.68) and among male laboratory scientists, after more than 10 years of work (4 cases), it was 3.11 (0.85-7.56). There was an elevated SIR for malignant melanoma among female scientists in laboratories (3.51, 0.96-8.98) and for male scientists in nonlaboratory departments (2.86, 1.05-6.22). The SIR for breast cancer among female laboratory scientists was 1.62 (0.78-2.98). CONCLUSIONS: The present findings lend some support to an excess of brain tumors among male scientists and of breast cancer in female scientists in biomedical research laboratories.

Adult↗
PubMed1999

Why can't we convince the young not to smoke?

Tobacco is the largest cause of preventable death and morbidity in the world. Significant progress has been made in national tobacco control programmes, followed by a significant reduction in smoking-associated diseases. However, other populations have taken up the habit and the worldwide surge in cigarette smoking by young people is particularly worrisome. Based on our own experience as well as reported data, we examined determinants of tobacco use, at the familial, peer and societal levels as well as various prevention strategies based on legislation, health promotion and society awareness. Reasons for failures include under-enforcement of legislation, uniform approach to diverse populations and too limited means. Recommendations for future actions should include integrated policies and health programmes. Most importantly, the society outlook on tobacco should be changed, making non-smoking the norm and the objective.

Adolescent↗
PubMed1999

Unexplained increases in cancer incidence in the United States from 1975 to 1994: possible sentinel health indicators?

To search for unexplained patterns in cancer incidence, we analyzed data from 1975 to 1994 that represent approximately 10% of the population of the United States. Our analysis focused on long-term time trends in incidence and on deviations from those trends attributable to birth cohorts or to calendar periods. On average, cancer incidence rose 0.8% annually in white women and 1.8% in white men. After removing several cancers related to smoking and increased screening, average annual increases fell to 0.1% in white women but persisted at 1.7% in white men. In particular, yearly increases in non-Hodgkin's lymphoma averaged 2.4% in white women and 4.7% in white men. Among men, incidence changes attributable to cohorts grew progressively larger from one cohort to the next. Cancer incidence patterns among black men and women were similar to those among whites despite smaller population sizes. Unexplained patterns of cancer incidence may signal changes in underlying risk factors and highlight the continuing need for research on cancer etiology and prevention.

Adult↗
PubMed1999

From in utero and childhood exposure to parental smoking to childhood cancer: a possible link and the need for action.

The objective of the present work is to critically summarize published studies and reassess the state of knowledge on a highly controversial topic: the potential association between prenatal exposure to passive smoking as well as maternal active smoking and postnatal exposure to environmental tobacco smoke (ETS) and enhanced incidence of childhood cancer. Elements to be considered include the substantial proportion of pregnant women who remain smokers, the widespread nature of exposure to ETS during pregnancy as well as during childhood, the known toxicology of tobacco smoke, and in particular sidestream smoke, characterized by a rich carcinogen content, the specific metabolism of foetuses and new-borns and finally the amount of epidemiologic data already available. We conducted a thorough review of the literature to identify studies either exclusively dealing with the effects of passive smoking on the occurrence of childhood cancers or more generally etiologic studies of cancer, be it overall or site-specific. We identified close to 50 publications presenting pertinent results from epidemiological investigations and about 50 more on mechanisms and metabolism, smoking in pregnancy and exposure to ETS as well as selected reviews and commentaries. Collaborative epidemiological studies were conducted in the United Kingdom (UK), USA, Sweden, Netherlands and internationally (France, Italy). In addition, other studies were also available from the USA, UK, Canada, Australia, Sweden, Italy, Denmark and People's Republic of China. The vast majority were case-control studies dealing with all cancers, leukaemia and lymphomas, central nervous system (CNS) tumours, Wilms' tumour, retinoblastoma, neuroblastoma, hepatoblastoma, rhabdomyosarcoma, bone and soft tissues tumours, germ cell tumours, as well as specific histological types of leukaemias, lymphomas or CNS tumours. No strong association between maternal smoking in pregnancy and/or exposure to ETS and childhood cancer is found. Yet, several studies found slightly increased relative risks, generally smaller than 1.5, i.e. the order of magnitude associated with some recognized hazards of exposure to ETS (1.2 to 1.3 for adult lung cancer and cardiovascular diseases). Tumours most often found associated with maternal smoking in pregnancy or ETS exposure are childhood brain tumours and leukaemia-lymphoma, with risks up to two or greater in selected studies. In a few studies, risks associated with paternal smoking are higher than the maternal ones. This evidence from human studies coupled with demonstration of genotoxic effects on the foetus of exposure to metabolites of tobacco smoke, and demonstrable presence of adducts should lead to strong recommendations aiming at fully protecting foetuses, new-borns and infants from tobacco smoke.

Brain Neoplasms↗
PubMed1999

[Chemoprevention of breast cancer by tamoxifen: should we still ask this question?].

Pharmacoprevention of cancer is an attractive concept. For breast cancer, several trials were set up some years ago. The largest one was stopped before its planned date of closure and demonstrated an early appearing reduction in breast cancer occurrence; in contrast, the other two trials did not find such a protective effect. The decision is all the more difficult because of tamoxifen side effects, including carcinogenicity. Currently, no definite conclusion can be drawn.

Anticarcinogenic Agents↗
PubMed1998

Impact of menopausal hormone-replacement therapy on clinical and laboratory characteristics of breast cancer.

Hormone-replacement therapy (HRT) is widely used by post-menopausal women. Although this treatment may slightly increase the incidence of breast cancer, more and more cases are diagnosed while women are taking HRT. The purpose of this study was to ascertain the influence of HRT on prognostic factors and outcome of breast cancer. Data on all breast-cancer patients, including precise information on HRT, was prospectively and systematically recorded in a data base. From 1985 to 1995, 1379 post-menopausal women fulfilled the eligibility criteria for this study. All were treated by us (P.B. and L.P.) in our ward of a large public hospital of Marseilles, France. The clinical features, laboratory findings and survival rates in 142 HRT users who developed breast cancer while being treated were compared with those of 284 matched never user breast-cancer patients. Patients who developed breast cancer during HRT had fewer locally advanced cancers and smaller and better-differentiated cancers. Lymph-node involvement was significantly less frequent in the user group than in the non-user group (non-significant). Estradiol receptivity was both qualitatively and quantitatively lower in users. There was no significant difference with regard to recurrence and metastasis-free survival and overall survival. We conclude that HRT does not affect the prognosis of breast cancer. Regular surveillance during HRT allows early detection of smaller lesions. The higher number of well-differentiated cancers and the distribution of hormone receptivity may reflect interaction between neoplastic tissue and exogenous hormones.

Adult↗
PubMed1998

A lack of neuroblastoma in Down syndrome: a study from 11 European countries.

An epidemiological investigation in 11 European countries comprising a total childhood population of 54.1 million children and using 8 separate data sources was conducted to evaluate the occurrence of neuroblastoma in Down syndrome (DS). No cases of DS were detected among 6724 infants and children with neuroblastoma, although more than five were expected. This highly significant result (P = 0.0045 according to the Poisson test) is consistent with data in the literature, which contains only two poorly detailed cases in epidemiological studies and one ganglioneuroma in a DS mosaic patient. Like other tumors, such as leukemias, testicular germ cell tumors and lymphomas are in excess in DS patients; the lack of neuroblastomas does not reflect a general decreased incidence of cancer but rather a specific underrepresentation of this precise tumor. S-100 b protein, the gene for which maps to the long arm of chromosome 21, (a) is overproduced in DS patients, (b) produces growth inhibition and differentiation of neural cells in vitro, (c) is abundant in good-prognosis neuroblastomas, and (d) has been shown to induce growth inhibition and differentiation and cell death in several human and murine neuroblastoma cell lines and could be responsible for this variation. Additional epidemiological and experimental studies are warranted to confirm our interpretation of these data.

Adolescent↗
PubMed1998

Prognostic factors for mortality in nasopharyngeal cancer: accounting for time-dependence of relative risks.

BACKGROUND: Few studies have assessed the role of prognostic factors for mortality from nasopharyngeal cancer and even fewer used multivariable methods. Most of these studies relied on the Cox model without testing the proportional hazards assumption. METHODS: A cohort of 76 cases of nasopharyngeal cancer recorded in the Rhône, France, between 1980 and 1985, was followed until 1995. Proportional hazards assumption was tested for each putative prognostic factor. Two multivariable models were built using forward selection of prognostic factors: the Cox model and a flexible model in which variables not meeting the proportional hazards assumption were represented by a time-varying hazard ratio. RESULTS: Only Epstein Barr Virus Nuclear Antigen (EBNA) serology, a marker of infection by the Epstein-Barr virus, and tumoral extent were selected in the analysis based on the Cox model. In contrast, four prognostic factors were significant at alpha = 0.05 level in the flexible model: initial EBNA serology, tumoral histology, age and tumoral extent, the last two not verifying the proportional hazards assumption. The relative risk of age increases with duration of follow-up whereas the effect of tumoral extent changes in a non-monotonic pattern. CONCLUSION: We showed the importance of taking into account the non-proportionality of hazards which can influence results and yield new insights about the role of prognostic factors in nasopharyngeal cancer. Because of the small size of our cohort, our results have to be confirmed in an independent study.

Adult↗
PubMed1998

Rethinking breast cancer risk and the environment: the case for the precautionary principle.

The World Health Organization recently reported that breast cancer has become the most common cancer in women throughout the world. Known risk factors account for less than half of all cases of breast cancer, and inherited germ line mutations occur in at most only 10% of all cases. Cumulative exposure to estradiol and other hormones links many of the established risk factors for breast cancer. This paper reviews epidemiologic and toxicologic evidence on breast cancer risks and presents a comprehensive construct of risk factors intended to focus on the identification of those factors that can be controlled or modified. We attempt to provide a framework for interpreting the etiologic interplay of endogenous metabolic changes and environmental changes in the etiology of breast cancer. The construct we develop distinguishes between those risk factors that are directly causal, such as ionizing radiation and inherited germ cell defects, those vulnerability factors that extend the time period during which the breast undergoes development, and those contributing factors that increase total hormonal stimulation of the breast. Some hormonally active compounds, such as those in soy and broccoli and other phytoestrogen-containing foods, can be protective against breast cancer, while others, such as some environmental contaminants, appear to increase the risk of the disease by increasing levels of harmful hormones. Efforts to explain patterns of breast cancer should distinguish between these different risk factors. Identification of vulnerability and contributing risk factors can foster the development of public policy to reduce the burden of this prevalent cancer. Prudent precautionary principles suggest that reducing exposure to avoidable or modifiable risk factors should receive high priority from the public and private sectors.

Breast Neoplasms↗
PubMed1998

Antenatal therapeutic drug exposure and fetal/neonatal tumours: review of 89 cases.

Although case reports on the association between neonatal tumours and maternal therapeutic drug use during pregnancy are cited regularly, no systematic review has been published. In a systematic search of the literature on fetal and neonatal tumours, we identified 36 malignant and 54 benign tumours in 89 fetuses and neonates prenatally exposed to various drugs. Six associations with in utero exposure are noteworthy: (1) phenytoin and neuroblastoma, as already suspected; (2) antibiotics and leukaemias; (3) hormonal treatment and vascular tumours; (4) acetaminophen (paracetamol) and fusocellular sarcoma; (5) acetaminophen in combination with petroleum products and hepatoblastoma; and (6) dicyclomine hydrochloride and teratomas. In view of the high level of consumption of drugs by pregnant women and the rarity of neonatal tumours, a possible carcinogenic effect is difficult to establish. However, some associations already observed in older infants, children and adults after antenatal and postnatal exposure to the same drugs are of note. We suggest that these drugs may act as carcinogens or as co-carcinogens in association with other physical and chemical agents and/or a particular genetic background. We therefore feel it is important to encourage the systematic collection, registration and publication of case reports on this subject. The hypotheses generated thereby could then be tested by formal epidemiological studies.

Carcinogens↗