154 research outputs found
Response to the letter to the editor sent by J.M. Broeders and S. Moss on our article entitled 'Pitfalls in using case-control studies for the evaluation of the effectiveness of breast screening programmes' that appeared in the European Journal of Cancer Prevention, issue of 20 December 2012
No full textWe thank J.M. Broeders and S. Moss for their interest in our article (Autier and Boniol, 2012). J.M. Broeders and S. Moss have rightly understood the problem we raised that when breast cancer mortality decreases for reasons unrelated to screening, data used for computing are biased and systematically lead to overestimation of the screening ability to decrease the risk of breast cancer death in general populations (effectiveness)
Measurement of solar ultraviolet radiation exposure for epidemiological studies
No full textLe rayonnement ultraviolet (UV) est un cancérigène pour lequel peu d’informations sur l’exposition des populations est disponible. L’intensité et les variations de l’exposition au rayonnement UV solaire, principale source d’exposition, a un impact sur la santé mais il est difficile de les surveiller. Le travail de cette thèse a permis de développer un outil pour une estimation quantitative de l’exposition individuelle à l’UV solaire pour l’épidémiologie. Nous avons créé un atlas des moyennes mensuelles d’irradiation journalière en Europe. Certaines données manquantes au niveau des pays nordiques en hiver ont dû être extrapolées. Nous avons vu que la saisonnalité est forte et que la répartition spatiale ne suit pas seulement le gradient de latitude. Par exemple, l’irradiation UV est plus élevée au sud des pays nordiques qu’au centre de l’Europe. Une enquête a été menée dans huit populations européennes afin d’estimer l’exposition individuelle. Ces populations ont des comportements différents vis-à-vis de l’exposition au soleil. Après une étape de modélisation pour estimer les données d’irradiation UV manquantes au nord de la Norvège sur l’ensemble de l’année, nous avons pu quantifier l’exposition chronique et l’exposition pendant les vacances dans trois populations (française, italienne et norvégienne). L’outil développé au cours de cette thèse pourra être utilisé pour de futures études épidémiologiques qui permettront de connaître l’exposition au rayonnement ultraviolet solaire de populations et de mieux comprendre son rôle dans l’étiologie de diverses maladies, telles que les cancers cutanés.Ultraviolet radiation (UV) is a carcinogenic agent for which little information on human exposure is available. The intensity and the changes of solar UV exposure, which is the main source of exposure, have an impact on health but are difficult to monitor. The work of this thesis led to the creation of a tool for quantitative estimation of individual exposure to solar UV that can be used in epidemiological studies. We created an atlas of monthly average daily radiation across Europe. Some missing values from the Nordic countries during winter had to be extrapolated. We observed a strong seasonality and characteristics in the spatial distribution which does not always follow the gradient of latitude. For instance, UV radiation is higher in the southern area of the Nordic countries than in central Europe. A survey was conducted in eight European populations to estimate individual exposure. These populations have different behaviours regarding sun exposure. After a step of modeling to estimate missing values in northern Norway throughout the year, we quantified chronic and holiday exposure in three populations (France, Italy and Norway). The tool developed during this thesis will be used for future epidemiological studies that will contribute to improving the knowledge about UV exposure in populations and better understanding its role in the aetiology of various diseases, such as skin cancers
Vitamin D and melanoma and non-melanoma skin cancer risk and prognosis : a comprehensive review and meta-analysis
No full textVitamin D is formed mainly in the skin upon exposure to sunlight and can as well be taken orally with food or through supplements. While sun exposure is a known risk factor for skin cancer development, vitamin D exerts anti-proliferative and pro-apoptotic effects on melanocytes and keratinocytes in vitro. To clarify the role of vitamin D in skin carcinogenesis, we performed a review of the literature and meta-analysis to evaluate the association of vitamin D serum levels and dietary intake with cutaneous melanoma (CM) and non-melanoma skin cancer (NMSC) risk and melanoma prognostic factors. Twenty papers were included for an overall 1420 CM and 2317 NMSC. The summary relative risks (SRRs) from random effects models for the association of highest versus lowest vitamin D serum levels was 1.46 (95% confidence interval (CI) 0.60-3.53) and 1.64 (95% CI 1.02-2.65) for CM and NMSC, respectively. The SRR for the highest versus lowest quintile of vitamin D intake was 0.86 (95% CI 0.63-1.13) for CM and 1.03 (95% CI 0.95-1.13) for NMSC. Data were suggestive of an inverse association between vitamin D blood levels and CM thickness at diagnosis. Further research is needed to investigate the effect of vitamin D on skin cancer risk in populations with different exposure to sunlight and dietary habits, and to evaluate whether vitamin D supplementation is effective in improving CM survival
Questionable method for estimating the influence of mammography screening on breast cancer mortality in the Netherlands
No full textAdjunctive ultrasonography for breast cancer screening
No full textRefers To Noriaki Ohuchi, Akihiko Suzuki, Tomotaka Sobue, Masaaki Kawai, Seiichiro Yamamoto, Ying-Fang Zheng, Yoko Narikawa Shiono, Hiroshi Saito, Shinichi Kuriyama, Eriko Tohno, Tokiko Endo, Akira Fukao, Ichiro Tsuji, Takuhiro Yamaguchi, Yasuo Ohashi, Mamoru Fukuda, Takanori Ishida, J-START investigator groups Sensitivity and specificity of mammography and adjunctive ultrasonography to screen for breast cancer in the Japan Strategic Anti-cancer Randomized Trial (J-START): a randomised controlled trial The Lancet, Volume 387, Issue 10016, 23–29 January 2016, Pages 341-348 PDF (234 K) Supplementary content Referred to by Noriaki Ohuchi, Akihiko Suzuki, Seiichiro Yamamoto, Shinichi Kuriyama, Takanori Ishida Adjunctive ultrasonography for breast cancer screening – Authors' reply The Lancet, Volume 387, Issue 10036, 11–17 June 2016, Pages 2381-2382 PDF (93 K) The primary goal of cancer screening is to decrease cancer mortality through detecting cancer at an earlier curable stage. Thus effective screening implies a decrease in the rate of advanced cancers. The randomised trial of Noriaki Ohuchi and colleagues suggests that the systematic addition of an ultrasonography examination to mammography and clinical breast examination increases the sensitivity of breast screening. Two screening rounds were done, but reported results concerned the first round only. The search for interval cancers was restricted to the period extending between the first and the second round and their stage distribution was not reported. Because of the absence of data about screen-detected cancers found at further rounds and interval cancers diagnosed during longer follow-up, the results of this single-round trial cannot be interpreted correctly. For example, how many of the extra 65 stage 0–1 cancers (36% of all stage 0 and 1 cancers) found with additional ultrasonography would represent overdiagnosis (ie, the detection of cancer that would not become clinical in the absence of screening)? If a sizeable portion of these 65 extra cancers represented overdiagnosis, then the gain in sensitivity is overestimated because earlier detection is of no relevance for overdiagnosed cancers. Another question is raised by the similar number of advanced (stage 2–4) cancers found in both groups. Do these similar numbers mean that the addition of ultrasonography does not improve the capacity of screening to detect cancers at an earlier stage? In our view, this Article adds confusion to investigations into the value of ultrasonography for breast screening. We declare no competing interests
Breast cancer screening: evidence of benefit depends on the method used
No full textAbstract In this article, we discuss the most common epidemiological methods used for evaluating the ability of mammography screening to decrease the risk of breast cancer death in general populations (effectiveness). Case-control studies usually find substantial effectiveness. However when breast cancer mortality decreases for reasons unrelated to screening, the case-control design may attribute to screening mortality reductions due to other causes. Studies based on incidence-based mortality have obtained contrasted results compatible with modest to considerable effectiveness, probably because of differences in study design and statistical analysis. In areas where screening has been widespread for a long time, the incidence of advanced breast cancer should be decreasing, which in turn would translate into reduced mortality. However, no or modest declines in the incidence of advanced breast cancer has been observed in these areas. Breast cancer mortality should decrease more rapidly in areas with early introduction of screening than in areas with late introduction of screening. Nonetheless, no difference in breast mortality trends has been observed between areas with early or late screening start. When effectiveness is assessed using incidence-based mortality studies, or the monitoring of advanced cancer incidence, or trends in mortality, the ecological bias is an inherent limitation that is not easy to control. Minimization of this bias requires data over long periods of time, careful selection of populations being compared and availability of data on major confounding factors. If case-control studies seem apparently more adequate for evaluating screening effectiveness, this design has its own limitations and results must be viewed with caution. See related Opinion article: http://www.biomedcentral.com/1741-7015/10/106 and Commentary http://www.biomedcentral.com/1741-7015/10/164</p
Questionable method for estimating the influence of mammography screening on breast cancer mortality in the Netherlands
No full textInternational audienc
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