Facteurs de risques environnementaux et/ou professionnels du cancer du testicule

Despite a low overall incidence (1% of all malignant neoplasms), testicular cancer is the most common malignancy among young men. Over the last 40 years, this incidence rate has substantially risen in most industrialised countries. However, the aetiology of testicular cancer remains largely unknown. Only cryptorchidism, and to a lesser extent a family history of testicular cancer, may be considered to be well established risk factors. Numerous attempts have been made to assess the potential role of occupational exposures in adult life as a risk factor for TC, but no clear hypotheses have yet emerged from previous studies in this field. A major limitation of all occupational studies is that no single toxic substance has been clearly identified, and consequently the significant association observed between some job titles and risk of testicular cancer must be interpreted very carefully. In this respect, comparative occupational studies of exposed and non-exposed workers including rigorous and valid job-matrix exposure assessment are needed to study potential relationships between certain occupational exposures and testicular cancer.     

Augmentation de l’incidence du cancer du testicule: état de la question

Although germ cell cancer is rare (about 1% of cancers in male), it is the commonest cancer in young man. Many studies in Europe, Northern America and Australia show that incidence rates of testis cancer are climbing. In Northern Europe and America, where cancer registration exist since the fifties, it is showed that overall age-adjusted incidence rate of testis cancer has increased more than 3 fold during the past 50 years. This increase affect particularly teenagers and young men. The increase of incidence rates is less documented in under developed countries but recent studies seem to confirm an increase of incidence rates in many parts of the world, even if testis cancer remain rarer in non Caucasian populations. Etiologies of a such increase are still unknown, but arguments point in view a possible relation between environmental hormone disrupters and many hormonodependent cancers, such as testicular neoplasm, the cancer of the breast or even prostate cancer. Epidemiological studies with large sample size are needed to identify risk factors responsible for the increase of incidence rates of testis cancer.     

Temporal and geographical variations of thyroid cancer incidence and mortality in France during 1986–2015: The impact of overdiagnosis

BackgroundFrance is among the countries showing fastest growth of thyroid cancer (TC) incidence and highest incidence rates in Europe. This study aimed to clarify the temporal and geographical variations of TC in France and to quantify the impact of overdiagnosis.MethodsWe obtained TC incidence data in 1986–2015, and mortality data in 1976–2015, for eight French departments covering 8% of the national population, and calculated the age-standardised rates (ASR). We estimated the average annual percent changes (AAPC) of TC incidence, overall and by department and histological subtype. Numbers and proportions of TC cases attributable to overdiagnosis were estimated by department and period, based on the comparison between the shape of the age-specific curves with that observed prior to changes in diagnostic practice.ResultsDuring 1986–2015, there were 13,557 TC cases aged 15–84 years. Large variations of TC incidence were observed across departments, with the highest ASR and the fastest increase in Isère. Papillary subtype accounted for 82.8% of the cases, and presented an AAPC of 7.0% and 7.6% in women and men, respectively. Anaplastic TC incidence decreased annually 3.0% in women and 0.8% in men. Mortality rates declined consistently for all departments. The absolute number (and proportion) of TC cases attributable to overdiagnosis grew from 1074 (66%) in 1986–1995 to 3830 (72%) in 2006–2015 in women, and varied substantially across departments.ConclusionsOverdiagnosis plays an important role in the temporal and regional variations of TC incidence in France. Monitoring the time trends and regulating the regional healthcare practice are needed to reduce its impact.     

Global Co‐Distribution of Light at Night (LAN) and Cancers of Prostate,Colon, and Lung in Men

The incidence rates of cancers in men differ by countries of the world. We compared the incidence rates of three of the most common cancers (prostate, lung, and colon) in men residing in 164 different countries with the population‐weighted light at night (LAN) exposure and with several developmental and environmental indicators, including per capita income, percent urban population, and electricity consumption. The estimate of per capita LAN exposure was a novel aspect of this study. Both ordinary least squares (OLS) and spatial error (SE) regression models were used in the analysis. We found a significant positive association between population exposure to LAN and incidence rates of prostate cancer, but no such association with lung cancer or colon cancer. The prostate cancer result is consistent with a biological theory and a limited number of previous studies of circadian disruption and risk. The LAN‐prostate cancer connection is postulated to be due to suppression of melatonin and/or disruption of clock gene function. An analysis holding other variables at average values across the 164 countries yielded a risk of prostate cancer in the highest LAN‐exposed countries 110% higher than in the lowest LAN exposed countries. This observed association is a necessary condition for a potentially large effect of LAN on risk of prostate cancer. However, it is not sufficient due to potential confounding by factors that increase the risk of prostate cancer and are also associated with LAN among the studied countries.     

International trends in the incidence of brain tumours in children and young-adults and their association with indicators of economic development

IntroductionChildhood brain tumours (CBTs) are the second most common type of cancer in individuals aged 0–24 years globally and cause significant morbidity and mortality. CBT aetiology remains poorly understood, however previous studies found higher CBT incidence in high-income countries (HIC) compared to low-middle income countries (LMIC), suggesting a positive relationship between incidence and wealth.Materials & methodsAggregated data from Cancer Incidence in Five Continents (CI5) were used to explore CBT epidemiology. Incidence rate ratios (IRR) compared CBT rates between twenty-five geographically and economically diverse countries. The relationship between incidence and economic development was explored using linear regression models and Spearman’s rank correlation tests. Trends in CBT incidence between 1978 and 2012 were investigated using average annual percentage changes (AAPC).ResultsCBT incidence was highest in North America and lowest in Africa. CBT incidence rates increased significantly with increasing GDP per capita (p = 0.006). Gini index was significantly negatively associated with CBT incidence. Incidence decreased with increasing income inequality within countries, indicated by higher Gini indices (p = 0.040). Increasing and decreasing CBT incidence trends were observed within individual countries, although only Italy (p = 0.02) and New Zealand (p < 0.005) experienced statistically significant changes over time.ConclusionsThe excess disease found in HIC may be explained by environmental risk factor exposure increasing CBT risk in wealthy populations. However, systematic limitations of substandard cancer detection and reporting in LMIC may mean incidence disparities result from misinformation bias rather than genuine differences in risk factor exposure. Further research is required to comprehensively describe CBT epidemiology and explain study findings.     

International Monetary Fund programs and tuberculosis outcomes in post-communist countries

Background

Previous studies have indicated that International Monetary Fund (IMF) economic programs have influenced health-care infrastructure in recipient countries. The post-communist Eastern European and former Soviet Union countries experienced relatively similar political and economic changes over the past two decades, and participated in IMF programs of varying size and duration. We empirically examine how IMF programs related to changes in tuberculosis incidence, prevalence, and mortality rates among these countries.

Methods and Findings

We performed multivariate regression of two decades of tuberculosis incidence, prevalence, and mortality data against variables potentially influencing tuberculosis program outcomes in 21 post-communist countries for which comparative data are available. After correcting for confounding variables, as well as potential detection, selection, and ecological biases, we observed that participating in an IMF program was associated with increased tuberculosis incidence, prevalence, and mortality rates by 13.9%, 13.2%, and 16.6%, respectively. Each additional year of participation in an IMF program was associated with increased tuberculosis mortality rates by 4.1%, and each 1% increase in IMF lending was associated with increased tuberculosis mortality rates by 0.9%. On the other hand, we estimated a decrease in tuberculosis mortality rates of 30.7% (95% confidence interval, 18.3% to 49.5%) associated with exiting the IMF programs. IMF lending did not appear to be a response to worsened health outcomes; rather, it appeared to be a precipitant of such outcomes (Granger- and Sims-causality tests), even after controlling for potential political, socioeconomic, demographic, and health-related confounders. In contrast, non-IMF lending programs were connected with decreased tuberculosis mortality rates (−7.6%, 95% confidence interval, −1.0% to −14.1%). The associations observed between tuberculosis mortality and IMF programs were similar to those observed when evaluating the impact of IMF programs on tuberculosis incidence and prevalence. While IMF programs were connected with large reductions in generalized government expenditures, tuberculosis program coverage, and the number of physicians per capita, non-IMF lending programs were not significantly associated with these variables.

Conclusions

IMF economic reform programs are associated with significantly worsened tuberculosis incidence, prevalence, and mortality rates in post-communist Eastern European and former Soviet countries, independent of other political, socioeconomic, demographic, and health changes in these countries. Future research should attempt to examine how IMF programs may have related to other non-tuberculosis–related health outcomes.     

Genotype by environment interaction for livability of dairy calves from first parity cows

Death of calves around parturition is a matter of concern for dairy farmers. Relatively high stillbirth rates and unfavourable trends have been reported for Holstein heifers in the Netherlands and several other countries. In our study, we investigated herd differences, genetic parameters and genotype by environment interaction for heifer calf livability. A large dataset with data from calvings between 1993 and 2012 of Dutch dairy farms was used. There were considerable differences between herds in livability of calves from heifers, with averages ranging from 74% to 95%. Both herds with relatively high and low averages showed the same negative trend between 1993 and 2012, with largest declines in herds with the lowest averages. We found that heritability and genetic variation of first parity livability were substantially larger in herd environments where the likelihood of stillbirth was high v. environments where stillbirth was at a low level. The genetic correlations between herd environment levels were all very close to unity, indicating that ranking of sires was similar for all environments. However, for herds with a relatively high stillbirth incidence selecting sires with favourable breeding values is expected to be twice as profitable as in herds with a relatively low stillbirth incidence.     

Tinea Capitis in the Paediatric Population in Milan, Italy: The Emergence of Trichophyton violaceum

Tinea capitis (TC) is the most common type of dermatophytosis in children. The epidemiology of TC depends on the geographical areas, and it changes over time. The aim of the study is to determine the incidence of TC and to identify the causative species in children observed at Dermatology Outpatient Department of the University of Milan, Italy, between January 2004 and December 2011. Four hundred and eighty-six children with suspected dermatomycosis were observed; TC was the most prevalent dermatomycoses with 86 cases. The most common isolated dermatophyte in scalp lesions was Trichophyton violaceum with 33 cases. The most recent epidemiological Italian studies still show zoophilic fungi as primary cause of TC. We are the first medical team in Italy to demonstrate a dominance of anthropophilic fungi, in particular T. violaceum.     

The incidence of dementia in England and Wales: findings from the five identical sites of the MRC CFA Study

BackgroundAlthough incidence of dementia is known to vary between nations, variation within country has not been explored because most incidence studies are single site or have insufficient numbers to compare sites. Few countries have conducted multisite incidence studies in order to facilitate national comparisons. This study aims to provide robust measures of the variation of the incidence of dementia across sites within England and Wales and produce overall estimates by age and sex.ConclusionThere is no evidence, within England and Wales, of variation in dementia incidence across sites. Dementia incidence rates do not tail off at the oldest ages.     

Incidence Patterns and Temporal Trends of Invasive Nonmelanotic Vulvar Tumors in Germany 1999-2011. A Population-Based Cancer Registry Analysis

ObjectivesTime trends on the incidence and characteristics of invasive vulvar cancer in Germany have so far been studied in few local population- and hospital based tumor registries. We aimed to provide an overview on recent developments of vulvar cancer in Germany, using population-based cancer registry data.MethodsWe analyzed the data on vulvar cancer of eight population-based German cancer registries for the period 1999-2011. ICD-10 codes and ICD-O-3 morphology codes were used to select site and histologic types. The annual percentage change was calculated on age-adjusted incidence rates with a joinpoint regression model.ResultsA total of 12,711 registered cases of invasive carcinoma of the vulva were included in the analyses, hereof were 12,205 of squamous cell origin. Age-standardized incidence rates of vulvar cancer annually increased by 6.7% (95% confidence limits: 5.6-7.9) from 1.7 per 100,000 women in 1999 to 3.6 per 100,000 women in 2011. An increase was observed among women of all ages, and especially between 30 and 69 years of age.ConclusionThe annual incidence of invasive carcinoma of the vulva nearly doubled in the past decade in Germany, considerably exceeding the rates observed in other Western European countries. A combination of changes in risk factors, and documentation practice might have contributed to the observed substantial increase in vulvar cancer incidence.     

On the Validity of Using Increases in 5-Year Survival Rates to Measure Success in the Fight against Cancer

Background

The 5-year survival rate of cancer patients is the most commonly used statistic to reflect improvements in the war against cancer. This idea, however, was refuted based on an analysis showing that changes in 5-year survival over time bear no relationship with changes in cancer mortality.

Methods

Here we show that progress in the fight against cancer can be evaluated by analyzing the association between 5-year survival rates and mortality rates normalized by the incidence (mortality over incidence, MOI). Changes in mortality rates are caused by improved clinical management as well as changing incidence rates, and since the latter can mask the effects of the former, it can also mask the correlation between survival and mortality rates. However, MOI is a more robust quantity and reflects improvements in cancer outcomes by overcoming the masking effect of changing incidence rates. Using population-based statistics for the US and the European Nordic countries, we determined the association of changes in 5-year survival rates and MOI.

Results

We observed a strong correlation between changes in 5-year survival rates of cancer patients and changes in the MOI for all the countries tested. This finding demonstrates that there is no reason to assume that the improvements in 5-year survival rates are artificial. We obtained consistent results when examining the subset of cancer types whose incidence did not increase, suggesting that over-diagnosis does not obscure the results.

Conclusions

We have demonstrated, via the negative correlation between changes in 5-year survival rates and changes in MOI, that increases in 5-year survival rates reflect real improvements over time made in the clinical management of cancer. Furthermore, we found that increases in 5-year survival rates are not predominantly artificial byproducts of lead-time bias, as implied in the literature. The survival measure alone can therefore be used for a rough approximation of the amount of progress in the clinical management of cancer, but should ideally be used with other measures.     

Twinning across the Developing World

Background

Until now, little was known about the variation in incidence of twin births across developing countries, because national representative data was lacking. This study provides the first comprehensive overview of national twinning rates across the developing world on the basis of reliable survey data.

Methods

Data on incidence of twinning was extracted from birth histories of women aged 15–49 interviewed in 150 Demographic and Health Surveys, held between 1987 and 2010 in 75 low and middle income countries. During the interview, information on all live births experienced by the women was recorded, including whether it was a singleton or multiple birth. Information was available for 2.47 million births experienced by 1.38 million women in a period of ten years before the interview. Twinning incidence was measured as the number of twin births per thousand births. Data for China were computed on the basis of published figures from the 1990 census. Both natural and age-standardized twinning rates are presented.

Results/Conclusions

The very low natural twinning rates of 6–9 per thousand births previously observed in some East Asian countries turn out to be the dominant pattern in the whole South and South-East Asian region. Very high twinning rates of above 18 per thousand are not restricted to Nigeria (until now seen as the world''s twinning champion) but found in most Central-African countries. Twinning rates in Latin America turn out to be as low as those in Asia. Changes over time are small and not in a specific direction.

Significance

We provide the most complete and comparable overview of twinning rates across the developing world currently possible.     

Évolution du cancer du testicule en France

As in many countries, the mortality rate of testicular cancer in France has decreased from 0.75 in 1978 to 0.25 per 100,000 in 2000 (standardized on world population). Over the same period, the incidence rate increased from 3.17 in 1978 to 4.82 per 100,000 in 2000 (standardized on world population). However, although the incidence of seminoma has increased continually with all birth cohorts, the incidence of non-seminomas first decreased for the men born between the first and second world wars and then increased at the same rate as the seminoma rate. No explanation for this pattern has yet been provided, but it does not appear to be simply an artefact. A North/South and East/West gradient has been observed, as the incidence varies from 4.0 in the South West to 8.0 in the North East. There is an estimated 1,500 new cases of testicular cancer each year in France, including 960 new cases for men between the ages of 15 and 40.     

Extra-pair paternity and egg dumping in birds: life history,parental care and the risk of retaliation

Molecular techniques have revealed striking variation among bird species in the rates of extra-pair paternity (EPP) and intraspecific brood parasitism (IBP). In terms of the proportion of broods affected, rates of EPP and IBP vary across species from 0-95% and 0-50%, respectively. Despite a plethora of hypotheses and several careful comparative analyses, few robust correlates of this interspecific variation have been identified. One explanation for this shortfall is that most comparative studies have tended to focus on contemporary ecological factors and ignored fundamental differences in reproductive biology that evolved millions of years ago. We show that, for both EPP and IBP, over 50% of interspecific variation is due to differences among taxonomic families and orders. Therefore, we test hypotheses that predict interspecific variation in the rate of alternative reproductive strategies should be associated with differences in life history and the form of parental care. Our analyses largely support these predictions, with high rates of reproductive cheating being associated with 'fast' life histories. High EPP rates are associated with high rates of adult mortality and reduced paternal care. High IBP rates are associated with high-fecundity rates. These patterns remain intact whether we use species as independent data points or evolutionary contrasts based on either molecular or morphological phylogenies. These results are interpreted as supporting the idea that alternative reproductive strategies are most common in taxa in which the risks of retaliation are low. We suggest a hierarchical explanation for interspecific variation in the incidence of alternative reproductive strategies. Variation between major avian lineages in the EPP and IBP rates are determined by fundamental differences in life history and parental care that evolved many millions of years ago. Variation between populations or individuals of the same species, however, are more likely to be determined by differences in contemporary ecological and genetic factors.     

The Incidence of End-Stage Renal Disease in the Diabetic (Compared to the Non-Diabetic) Population: A Systematic Review

End-stage renal disease (ESRD) in diabetes is a life threatening complication resulting in a poor prognosis for patients as well as high medical costs. The aims of this systematic review were (1) to evaluate the incidence of ESRD due to all causes and due to diabetic nephropathy in the diabetic population and differences between incidences of ESRD with respect to sex, ethnicity, age and regions, (2) to compare incidence rates in the diabetic and non-diabetic population, and (3) to investigate time trends. The systematic review was conducted according to the PRISMA group guidelines by performing systematic literature searches in the biomedical databases until January 3^rd 2015; thirty-two studies were included. Among patients with incident type 1 diabetes the 30-year cumulative incidence ranged from 3.3% to 7.8%. Among patients with prevalent diabetes, incidence rates of ESRD due to all causes ranged from 132.0 to 167.0 per 100,000 person-years, whereas incidence rates of ESRD due to diabetic nephropathy varied from 38.4 to 804.0 per 100,000 person-years. The incidence of ESRD in the diabetic population was higher compared to the non-diabetic population, and relative risks varied from 6.2 in the white population to 62.0 among Native Americans. The results regarding time trends were inconsistent. The review conducted demonstrates the considerable variation of incidences of ESRD among the diabetic population. Consistent findings included an excess risk when comparing the diabetic to the non-diabetic population and ethnic differences. We recommend that newly designed studies should use standardized methods for the determination of ESRD and population at risk.     

Increasing burden of melanoma in Croatia

Melanoma consists 4-5% of all skin cancers, but it contributes to 71-80% of skin cancers deaths. It is controversial whether worldwide increases in melanoma incidence represent a true epidemic but at the same time that dramatic increase in incidence occur in setting of relatively stable mortality trends, observed in Croatia also. The majority of authors accept that main risk factors for melanoma relate to environmental exposure and genetics with epidemiologic studies linking sun exposure to melanoma development. Data were obtained from Croatian cancer register for patients diagnosed between 1999 and 2008, for malignant melanoma of the skin (ICD-10 code C43) at national level and from 2003 to 2008, at the County level (Primorsko-goranska County). Melanoma incidence nearly doubled in males from 8.75 to 13.4/10(5) per year, fold in females from 9.1 at the start of observation to the end of 12.0/10(5) per year in Croatia. Melanoma incidence rates were much more higher for Primorsko-goranska County with range from 10.1 to 17.5/10(5) per year. The greatest increase of melanoma incidence rates was in males 60 years and over year group at diagnosis. National comparison of variation in cancer incidence by region and age can provide basis for public health prevention. It requires the integration of information on risk factors, incidence that could help to reduce regional inequalities in incidence and reduce the future cancer incidence.     

Regions of High Out-Of-Hospital Cardiac Arrest Incidence and Low Bystander CPR Rates in Victoria,Australia

BackgroundOut-of-hospital cardiac arrest (OHCA) remains a major public health issue and research has shown that large regional variation in outcomes exists. Of the interventions associated with survival, the provision of bystander CPR is one of the most important modifiable factors. The aim of this study is to identify census areas with high incidence of OHCA and low rates of bystander CPR in Victoria, AustraliaMethodsWe conducted an observational study using prospectively collected population-based OHCA data from the state of Victoria in Australia. Using ArcGIS (ArcMap 10.0), we linked the location of the arrest using the dispatch coordinates (longitude and latitude) to Victorian Local Government Areas (LGAs). We used Bayesian hierarchical models with random effects on each LGA to provide shrunken estimates of the rates of bystander CPR and the incidence rates.ResultsOver the study period there were 31,019 adult OHCA attended, of which 21,436 (69.1%) cases were of presumed cardiac etiology. Significant variation in the incidence of OHCA among LGAs was observed. There was a 3 fold difference in the incidence rate between the lowest and highest LGAs, ranging from 38.5 to 115.1 cases per 100,000 person-years. The overall rate of bystander CPR for bystander witnessed OHCAs was 62.4%, with the rate increasing from 56.4% in 2008–2010 to 68.6% in 2010–2013. There was a 25.1% absolute difference in bystander CPR rates between the highest and lowest LGAs.ConclusionSignificant regional variation in OHCA incidence and bystander CPR rates exists throughout Victoria. Regions with high incidence and low bystander CPR participation can be identified and would make suitable targets for interventions to improve CPR participation rates.     

Links between morphology and function of the pollen wall: an experimental approach

The wall of pollen grains exhibits morphological variation in many features including apertures, ornamentation and thickness, but the function of these characters remains to be clarified. It has been suggested that they are involved in the accommodation of volume changes (harmomegathy). To investigate this further, we developed a protocol that induces a controlled hydration of the pollen without affecting its metabolism and we applied it to six species differing in their pollen wall morphology. The entry of water caused pollen swelling and volume increase leading to breakage of the wall and/or of the plasma membrane, such that the per cent of intact grains was negatively correlated with the level of hydration. Qualitative and quantitative differences were observed between the species. Breakage of the exine was observed only in pollen lacking apertures and with thin exine. Variation in the exine ornamentation and thickness could explain the interspecific differences observed for the rates of breakage of the plasma membrane. Our results suggest that pollen wall morphology matters for survival and maintenance of pollen integrity further to volume increase due to hydration. We propose a rationale for future studies that should allow disentangling the contribution of different pollen morphological and physiological features to harmomegathy.