European guidelines for quality assurance in colorectal cancer screening and diagnosis: overview and introduction to the full supplement publication.

Population-based screening for early detection and treatment of colorectal cancer (CRC) and precursor lesions, using evidence-based methods, can be effective in populations with a significant burden of the disease provided the services are of high quality. Multidisciplinary, evidence-based guidelines for quality assurance in CRC screening and diagnosis have been developed by experts in a project co-financed by the European Union. The 450-page guidelines were published in book format by the European Commission in 2010.  They include 10 chapters and over 250 recommendations, individually graded according to the strength of the recommendation and the supporting evidence. Adoption of the recommendations can improve and maintain the quality and effectiveness of an entire screening process, including identification and invitation of the target population, diagnosis and management of the disease and appropriate surveillance in people with detected lesions. To make the principles, recommendations and standards in the guidelines known to a wider professional and scientific community and to facilitate their use in the scientific literature, the original content is presented in journal format in an open-access Supplement of Endoscopy. The editors have prepared the present overview to inform readers of the comprehensive scope and content of the guidelines.

European guidelines for quality assurance in colorectal cancer screening and diagnosis. First Edition--Evaluation and interpretation of screening outcomes.

Multidisciplinary, evidence-based guidelines for quality assurance in colorectal cancer screening and diagnosis have been developed by experts in a project coordinated by the International Agency for Research on Cancer. The full guideline document covers the entire process of population-based screening. It consists of 10 chapters and over 250 recommendations, graded according to the strength of the recommendation and the supporting evidence. The 450-page guidelines and the extensive evidence base have been published by the European Commission. The chapter on evaluation and interpretation of screening outcomes includes 20 graded recommendations. The content of the chapter is presented here to promote international discussion and collaboration by making the principles and standards recommended in the new EU Guidelines known to a wider professional and scientific community. Following these recommendations has the potential to enhance the control of colorectal cancer through improvement in the quality and effectiveness of the screening process, including multi-disciplinary diagnosis and management of the disease.

Modelling the effect of breast cancer screening on related mortality using French data.

INTRODUCTION: This study aimed at modelling the effect of organized breast cancer screening on mortality in France. It combined results from a Markov model for breast cancer progression, to predict number of cases by node status, and from relative survival analyses, to predict deaths. The method estimated the relative risk of mortality at 8 years, in women aged 50-69, between a population screened every two years and a reference population. METHODS: Analyses concerned cases diagnosed between 1990 and 1996, with a follow-up up to 2004 for the vital status. Markov models analysed data from 3 screening programs (300,000 mammographies) and took into account opportunistic screening among participants to avoid bias in parameter's estimates. We used survival data from cancers in the general population (n=918, 7 cancer registries) and from screened cancers (n=565, 3 cancer registries), after excluding a subgroup of screened cases with a particularly high survival. Sensitivity analyses were performed. RESULTS: Markov model main analysis lacked of fit in two out of three districts. Fit was improved in stratified analyses by age or district, though some lack of fit persisted in two districts. Assuming 10% or 20% overdiagnosed screened cancers, mortality reduction was estimated as 23% (95% CI: 4, 38%) and 19% (CI: -3, 35%) respectively. Results were highly sensitive to the exclusion in the screened cancers survival analysis. Conversely, RR estimates varied moderately according to the Markov model parameters used (stratified by age or district). CONCLUSION: The study aimed at estimating the effect of screening in a screened population compared to an unscreened control group. Such a control group does not exist in France, and we used a general population contaminated by opportunistic screening to provide a conservative estimate. Conservative choices were systematically adopted to avoid favourable estimates. A selection bias might however affect the estimates, though it should be moderate because extreme social classes are under-represented among participants. This modelling provided broad estimates for the effect of organized biennial screening in France in the early nineteen-nineties. Results will be strengthened with longer follow-up.

[Breast cancer screening: are results of French and international programmes comparable?]. / Dépistage organisé des Cancers du Sein: peut-on comparer les résultats du programme français aux résultats internationaux?

Full coverage of the national breast cancer screening programme was obtained in 2004. The new protocol was published in 2001. It changed the organisation implemented since 1994 for a better fit with the French decentralized health care system. Consequences on health results were analysed explaining related medical and sociological factors. The main change was the rate of positive mammograms which differed from the recall rate given in the European recommendations. With the new protocol the rate of assessments more than doubled: 6% in year 2000 and 14% in 2003. International comparisons are difficult since each country has a different organisation. Moreover the coexistence in France of organized screening and opportunistic screening causes a complex issue for evaluation of impact indicators of this population based programme.

International comparison of performance measures for screening mammography: can it be done?

OBJECTIVE: Published screening mammography performance measures vary across countries. An inter-national study was undertaken to assess the comparability of two performance measures: the recall rate and positive predictive value (PPV). These measures were selected because they do not require identification of all cancers in the screening population, which is not always possible. SETTING: The screening mammography programs or data registries in 25 member countries of the International Breast Cancer Screening Network (IBSN). METHODS: In 1999 an assessment form was distributed to IBSN country representatives in order to obtain information on how screening mammography was performed and what specific data related to recall rates and PPV were collected. Participating countries were then asked to provide data to allow calculation of recall rates, PPV and cancer detection rates for screening mammography by age group for women screened in the period 1997-1999. RESULTS: Twenty-two countries completed the assessment form and 14 countries provided performance data. Differences in screening mammography delivery and data collection were evident. For most countries, recall rates were higher for initial than for subsequent mammograms. There was no consistent relationship of initial to subsequent PPV, although PPV generally decreased as the recall rate increased. Recall rates decreased with increasing age, while PPV increased as age increased. CONCLUSION: Similar patterns for mammography performance measures were evident across countries.However, the development of a more standardized approach to defining and collecting data would allow more valid international comparisons, with the potential to optimize mammography performance. At present, international comparisons of performance should be made with caution due to differences in defining and collecting mammography data.

The epidemiology of AIDS-associated non-Hodgkin's lymphoma in the World Health Organization European Region.

This paper describes the epidemiology of AIDS-associated non-Hodgkin's lymphoma (NHL) in the World Health Organization (WHO) European Region. Data, collected by the WHO Collaborating Centre on AIDS in Paris, France, were derived from the national AIDS surveillance systems of 21 countries. Among 53,042 cases reported as of the end of June 1991, 1,617 (3.0%) had NHL as the presenting clinical manifestation of AIDS. The proportion of cases presenting with NHL ranged from 1.1% in children infected perinatally to 3.9% among haemophiliacs. In comparison with intravenous drug users (IVDUs) (2.6% of whom had NHL), a moderate excess was found among homosexual or bisexual men (odds ratio - OR -:1.2, 95% confidence interval - CI -:1.0-1.3). Over time, the proportion of NHL was constant, but whereas among homosexual or bisexual men the frequency of NHL as AIDS-indicator disease significantly increased (9.7% per year), among IVDUs a significant downward trend emerged (17.1% per year). In respect to age, two peaks of NHL were seen at the age groups 10-19 (3.8%) and 50-59 (4.3%). The proportion of AIDS-associated NHL significantly increased with increasing age among homosexual and bisexual men and heterosexuals whereas it decreased among IVDUs. All these differences, however, have to be interpreted cautiously on account of the limitations of the reporting systems.