227 research outputs found
Vitamin D status as a synthetic biomarker of health status
No full textAutier, Philippe ENG 2016/01/01 06:00 Endocrine. 2015 Dec 30.International audienceno abstrac
Global trends in dietary quality
No full textMullie, Patrick Autier, Philippe eng Comment Letter England 2015/09/20 06:00 Lancet Glob Health. 2015 Oct;3(10):e592. doi: 10.1016/S2214-109X(15)00081-9.International audienceno abstrac
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)
Self-Selection Bias in Randomized and Observational Studies on Screening Mammography: A Quantitative Assessment
No full textPhilippe Autier International Prevention Research Institute (IPRI), Lyon, 69002, FranceCorrespondence: Philippe Autier, International Prevention Research Institute (iPRI), Lyon, 69002, France, Email [email protected]: Observational studies aimed at evaluating the effectiveness of screening mammography are prone to self-selection due to differences in personal characteristics between women attending and those not attending screening. A method based on a quantity Dr has been promoted to correct for this bias, Dr being the risk of breast cancer death in a group of women not attending screening compared to the risk of breast cancer death in a population without screening.Objective: To estimate the amount of self-selection in observational studies aimed at evaluating screening mammography effectiveness and to estimate Dr quantities needed to correct for this bias.Methods: A first step quantified self-selection and Dr quantities specific to Swedish randomized trials using the most recent publications. A second step estimated self-selection specific to cohort studies on screening mammography effectiveness using the relative risk of 0.54 for all-cause death from these studies and the relative risk of all-cause death of 0.98 reported in Swedish trials. Using self-selection estimated from cohort studies, the Dr quantity needed to correct observational studies on screening mammography effectiveness was estimated. In a last step, corrections for self-selection in observational studies on screening mammography were retrieved.Results: The self-selection bias was 2.10 in Swedish trials. Self-selection in cohort studies was computed as (0.98/0.54) = 1.78. The Dr quantity required to correct results of observational studies was 1.53. In 19 case-control and cohort studies on screening mammography effectiveness, the median Dr quantity used for correction purposes was 1.16 (IQR: 1.11– 1.28).Conclusion: Compared to women attending screening, the risk of breast cancer death was approximately two times greater in women not attending screening. This increased risk was independent of screening effects. Most observational studies have overestimated the effectiveness of screening mammography because they used Dr quantities that were too small to correct for self-selection.Plain Language Summary: Women attending and not attending mammography screening differ in several ways. Non-attending women have a higher risk of dying from breast cancer because they tend to be less health aware, more deprived, have more comorbidities, develop more aggressive breast cancer, and to be less compliant with therapies. This phenomenon is called self-selection. Consequently, observational studies (ie case-control and cohort studies) have nearly always found that women attending screening are at a lower risk of breast cancer death than women not attending screening. In a previous publication, we showed that methods used to date to control self-selection removed only a fraction of this bias. The objective of this study was to quantify how much of the changes in the risk of breast cancer death reported by observational studies on mammography screening was due to self-selection bias. To this end, we used a method allowing us to estimate the amount of self-selection in populations where women are invited to screening. The method was based on the fact that screening mammography cannot influence causes of death other than breast cancer. Self-selection was first quantified using most recent results of Swedish randomized trials on screening mammography, and then in cohort studies that estimated the reduction in the risk of breast cancer death associated with attendance to screening mammography. Our study found that compared to women who attended screening, women who did not attend screening had an approximately 2-fold increased risk of breast cancer death. This increased risk was independent of screening effects on the risk of breast cancer death. Hence, observational studies conducted to date have overestimated the health benefits of mammography screening.Keywords: breast, cancer, screening, selection, bia
Do International Trends in Cancer Incidence and Mortality Reflect Expectations from Cancer Screening?
No full textGravure ionique reactive des semiconducteurs III-V avec controle in situ par interferometrie laser : applications a l'optique integree
No full textSIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc
Risk factors and biomarkers of life-threatening cancers
No full textThere is growing evidence that risk factors for cancer occurrence and for cancer death are not necessarily the same. Knowledge of cancer aggressiveness risk factors (CARF) may help in identifying subjects at high risk of developing a potentially deadly cancer (and not just any cancer). The availability of CARFs may have positive consequences for health policies, medical practice, and the search for biomarkers. For instance, cancer chemoprevention and cancer screening of subjects with CARFs would probably be more ethical and cost-effective than recommending chemoprevention and screening to entire segments of the population. Also, the harmful consequences of chemoprevention and of screening would be reduced while effectiveness would be optimised. We present examples of CARF already in use (e.g. mutations of the breast cancer (BRCA) gene), of promising avenues for the discovery of biomarkers thanks to the investigation of CARFs (e.g. breast radiological density and systemic inflammation), and of biomarkers commonly used that are not real CARFs (e.g. certain mammography images, prostate-specific antigen (PSA) concentration, nevus number)
Efficient treatments reduce the cost-efficiency of breast cancer screening
No full textIn this issue, Birnbaum and colleagues evaluate whether the availability of efficient adjuvant and chemotherapy treatments would have changed reductions in the risk for breast cancer death reported by randomized trials on breast cancer screening. The editorialist discusses these results and the implications for women having breast cancer screening
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