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This work presents a brief overview of Markov models in cancer screening evaluation and focuses on two specific models. A three-state model was first proposed to estimate jointly the sensitivity of the screening procedure and the average duration in the preclinical phase, i.e. the period when the cancer is asymptomatic but detectable by screening. A five-state model, incorporating lymph node involvement as a prognostic factor, was later proposed combined with a survival analysis to predict the mortality reduction associated with screening. The strengths and limitations of these two models are illustrated using data from French breast cancer service screening programmes. The three-state model is a useful frame but parameter estimates should be interpreted with caution. They are highly correlated and depend heavily on the parametric assumptions of the model. Our results pointed out a serious limitation to the five-state model, due to implicit assumptions which are not always verified. Although it may still be useful, there is a need for more flexible models. Over-diagnosis is an important issue for both models and induces bias in parameter estimates. It can be addressed by adding a non-progressive state, but this may provide an uncertain estimation of over-diagnosis. When the primary goal is to avoid bias, rather than to estimate over-diagnosis, it may be more appropriate to correct for over-diagnosis assuming different levels in a sensitivity analysis. This would be particularly relevant in a perspective of mortality reduction estimation.

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Mammographic density is a risk factor for breast cancer and it reflects variations in the tissue composition of the breast. It is notably influenced by body mass index and by endogenous hormones as well as hormone replacement therapy (HRT). The pathways that are responsible for the increase in mammographic density following exposure to hormones and those that increase risk of breast cancer are probably not the same. Careful clinical and mammographic follow-up is appropriate in women undergoing HRT because an increase in density is not only a risk factor for breast cancer but it also reduces screening sensitivity. We present a case in which mammographic density decreased after menopause, then dramatically increased after HRT and finally, surgical biopsy allowed the diagnosis of an infiltrative breast carcinoma. We discuss appropriate HRT changes in case of increasing mammographic density.

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PURPOSE: To assess difficulties in reading screening mammographies related to hormone replacement therapy (HRT) in the setting of a breast cancer screening program. Disagreement between two readers is used as the assessment criterion. POPULATION AND METHODS: The study population consisted of all women participating in the ADEMAS breast cancer screening program in Bas-Rhin (France). Agreement between the two radiologists was considered when the same global conclusion (call-back or not of the women for further examination) or the same conclusion for each of the nine possible lesions was observed. RESULTS: HRT is associated with a higher risk of disagreement between the two radiologists on global conclusion and on opacities. Conversely, disagreement risk is lowered for microcalcifications (whether benign or malignant) for HRT users. CONCLUSION: HRT is associated with a higher risk of disagreement on global conclusion. This has an impact on whether the women should be called-back or not according to reading of breast cancer screening program mammographies.

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PURPOSE: This paper presents the cost of two decentralised breast cancer screening programmes in France, in the Bas-Rhin and the Bouches du Rhône districts. Materials and methods. The costs directly related to running the two screening programmes were collected for the time period 1990-1997. Only direct costs of each programme, excluding assessment and treatment costs, are included in the cost analysis. Costs are presented per screening period, per programme attender and per cancer detected by screening. RESULTS: The screening programme costs an average of 397 francs per woman screened and 90,828 francs per cancer detected in the Bas-Rhin, and 379 francs and 76,159 francs, respectively, in the Bouches du Rhône. CONCLUSIONS: These costs are high compared to those of existing centralised programmes. Further research is needed to investigate means of ensuring the optimal efficiency of these programmes. The results of this study may help guide future decisions on the further development of breast cancer screening in France.

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Since 1989, in the French department of Bas-Rhin, a breast cancer screening program in going on and its results are presented here. This program, concerning women of 50 to 65 years-old, is decentralized, based on private or public radiologists and the motivation of women because there is no invitation. The interval between screening test is 2 years. After 8 years, the results are rather satisfactory: participation rate of the initial cohort is 77% in December 31st 1997, participation at incident screenings is above than 85%, early indicators (recall rate, detection rate, PPV of screening, PPV of biopsy) are improving with time to attain numbers like international studies. The ADEMAS program shows that a decentralized screening program, based on existing medical structures is possible in France. Anyway, it must be organized, evaluated at any time, with a quality assurance system to guarantee the women the best taking charge.

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Cancer registries are necessary to evaluate the efficacy of cancer screening programmes. They provide early indicators of screening efficacy, needed to correct certain campaign failings without waiting for the mortality data, available only 7 to 10 years after the beginning of the screening. They allow to mesure the screening effect not only on the screened women, but also on the entire target population. They also allow to mesure the negative and deleterious effects of the screening. Finally, they are essential to all cost/efficacy study. The evaluation of the breast cancer screening programme in the French department of Bas-Rhin by the cancer Registry showed very quickly the interest of the mesures concerning the quality assurance programme and to estimate on the first screen results basis, that it will be difficult to reduce the mortality by breast cancer to 25%.

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Sanitary U bends are very contaminated places from a microbiological point of view. They may even be dangerous for immunocompromised patients. Although daily chloride disinfection of U-bends is ineffective, it seems to work when performed after each use of sanitary devices. On line disinfection reduces not only U-bend bacteriological contamination but also all surrounding surfaces.

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A mammographic breast cancer screening began in May 1989 in the Bas-Rhin. It has been selected by "Europe against Cancer" for France. Its aim is not to prove the efficiency of mammography screening by one view every two years, as many studies has proven it. Its purpose is to find the best methodological model for a national campaign. Its principles are to change attitudes and to obtain the active participation of the physicians without creating new structures. This campaign is offered to women aged 50 to 65, living in Bas-Rhin (74,200 women) without individual convocations. Their participation is obtained by a continuous information and motivation. The mammographic examinations are taken in charge by the Health Insurance and performed by the radiologists who have signed a convention. The homogeneity of the results is assured by a double and triple reading under the responsibility of the ADEMAS. In May 1990, after one year, 17,228 women had presented to the screening test. The positive test rate is 7.6% and 7.6% of the women had a diagnostic procedure which indicated a biopsy for 188 women. Among the first 176 histological results, 76 cancers have been diagnosed, 100 women had a benign lesion. The ratio cancer/benign lesion is 0.76.

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