Clasificación y características del cáncer de intervalo en el programa de detección precoz de cáncer de mama en el Principado de Asturias

Objective

To review and classify the interval cancers found in the Principality of Asturias's Breast Cancer Screening Program (PDPCM). A secondary objective was to determine the histological characteristics, size, and stage of the interval cancers at the time of diagnosis.

Material and methods

We included the interval cancers in the PDPCM in the period 2003-2007. Interval cancers were classified according to the breast cancer screening program protocol, with double reading without consensus, without blinding, with arbitration. Mammograms were interpreted by 10 radiologists in the PDPCM.

Results

A total of 33.7% of the interval cancers could not be classified; of the interval cancers that could be classified, 40.67% were labeled true interval cancers, 31.4% were labeled false negatives on screening, 23.7% had minimal signs, and 4.23% were considered occult. A total of 70% of the interval cancers were diagnosed in the year of the period between screening examinations and 71.7% were diagnosed after subsequent screening. A total of 76.9% were invasive ductal carcinomas, 61.1% were stage II when detected, and 78.7% were larger than 10 mm when detected.

Conclusions

The rate of interval cancers and the rate of false negatives in the PDPCM are higher than those recommended in the European guidelines. Interval cancers are diagnosed later than the tumors detected at screening. Studying interval cancers provides significant training for the radiologists in the PDPCM.     

Cribado poblacional de cáncer de mama. Certezas,controversias y perspectivas de futuro

Population-based breast cancer screening programs based on mammography must maintain a high level of quality, so the results must be constantly monitored. Although most authors consider that these programs have decreased the mortality due to breast cancer by about 30%, others claim that the mortality has decreased by only about 12% due to errors in the randomization of patients, because the rate of advanced tumors has hardly decreased and because adjuvant treatment also improves survival. Other criticisms focus on overdiagnosis and overtreatment. We believe that despite the unquestionable value of mammographic screening, we should be open to certain changes such as the stratification of patients by their level of risk and the introduction of complementary techniques like tomosynthesis, ultrasonography, and magnetic resonance imaging in selected cases.     

Konzept und Durchführung der Modellprojekte für Mammographiescreening in Deutschland

The carriers of the German Statutory Health Care System have recognized that only mammographic screening according to the European Guidelines for the Quality Assurance of Mammography Screening will permit early detection of breast cancer with an acceptable risk/benefit ratio. In the German pilot projects, regional mammography screening programmes according to the European guidelines are being tested in the framework of the German health care system. The European guidelines require comprehensive quality assurance of all relevant steps in the chain of events involved in screening, from invitation on to therapy and follow-up. Such comprehensive quality assurance involves several medical specialities and other professional groups dealing with out-patient and in-patient health care and requires long-term cooperation with public institutions (population registries, cancer registries). The objective of the pilot projects is to test the organizational and legal conditions essential to introduction of a mammographic screening programme according to the European quality assurance guidelines in Germany.     

Breast cancer screening in Canada: a review.

Organized screening for breast cancer in Canada began in 1988 and has been implemented in all provinces and 2 of the 3 territories. Quality initiatives are promoted through national guidelines which detail best practices in various areas, including achieving quality through a client-service approach, recruitment and capacity, retention, quality of mammography, reporting, communication of results, follow-up and diagnostic workup, and program evaluation; it also offers detailed guidelines for the pathological examination and reporting of breast specimens. The Canadian Breast Cancer Data Base is a national breast cancer screening surveillance system whose objective is to collect information from provincial-screening programs. These data are used to monitor and evaluate the performance of programs and allow comparison with national and international results. A series of standardized performance indicators and targets for the evaluation of performance and quality of organized breast cancer screening programs have been developed from the data base. Although health care is a provincial responsibility in Canada, the collective reporting and comparison of results both nationally and internationally is beneficial in evaluating and refining both screening programs and individual radiologist performance. The results of Canadian performance indicators compare favourably with those of other well-established international screening programs. There are variations in performance indicators across the provinces and territories, but these differences are not extreme.     

Mammographiescreening in Deutschland

Available data suggest that early detection of breast cancer by mammography screening can reduce mortality by about 25%. Intensified monitoring of women with a family history of breast cancer and regular general screening have recently been introduced in Germany. The screening program is expected to be fully established by 2008. Following its successful introduction (participation rates between 65 and 80%), the German screening program will be conducted and evaluated in accordance with the European guidelines. At least in the screening trials that were conducted prior to the now established screening program the quality criteria were more than fulfilled (e.g. cancer detection rate in Bremen 8.7, Wiesbaden 9.4, Weser-Ems region 8.3/1000). Additional parameters that can be taken into account for quality assurance are the overdiagnosis bias, lead time bias, length bias and selection bias. Moreover, there are some factors that are specific to the German program compared with the breast cancer screening programs already established in other countries. One of these is the intensified screening program for high-risk women (ca. 5% of all carcinomas) and as a result fewer women with an increased genetic risk of breast cancer will be represented in the general screening program. The German screening program involves only a few university centers and hospital-based physicians, which may have adverse effects on research and development as well as mammography training in the future. Therefore, the screening program should also provide for the investigation of new techniques or emerging techniques (e.g. CAD systems in screening mammography) in the future.     

Mammographiescreening in Deutschland

The concept of mammography screening is based on the expectation that early diagnosis in a preclinical tumor stage enables less invasive treatment with a better prognosis than detection in advanced tumor stages. Mammography screening was implemented in European countries after results from large randomized controlled trials showed that regular screening led to a significant reduction in breast cancer mortality by 25-30?%. Recently, a major review of breast cancer screening services in Europe concluded that the benefits of screening clearly outweighed the disadvantages. In comparison to other European screening nations the German mammography screening program is relatively new. The challenge to prove the effectiveness by reduction in mortality still has to be solved. Continuous evaluation and optimization concerning the quality of structure, processes and results already confirm the high quality of the nationwide German screening services.     

Current Guidelines and Gaps in Breast Cancer Screening

Breast cancer is the most common nonskin cancer in women and the second leading cause of cancer death for women in the United States. Mammography screening is proven to significantly decrease breast cancer mortality, with a 40% or more reduction expected with annual use starting at age 40 for women of average risk. However, less than half of all eligible women have a mammogram annually. The elimination of cost sharing for screening made possible by the Affordable Care Act (2010) encouraged screening but mainly for those already insured. The United States Preventive Services Task Force 2009 guidelines recommended against screening those 40 to 49 years old and have left women over 74 years of age vulnerable to coverage loss. Other populations for whom significant gaps in risk information or screening use exist, including women of lower socioeconomic status, black women, men at higher than average risk of breast cancer, and sexual and gender minorities. Further work is needed to achieve higher rates of screening acceptance for all appropriate individuals so that the full mortality and treatment benefits of mammography screening can be realized.     

Audit procedures in the National Breast Screening Study: mammography interpretation

Audit procedures for mammography interpretation in a national breast cancer screening program are described. Agreement between radiologists at five screening centers and a single reference radiologist was evaluated based on mammograms at initial screen in 739 women not known to have breast cancer and 204 breast cancer cases detected at or within a year of initial screen. Kappa statistics, used to measure agreement in the interpretation of mammograms between the reference and center radiologists beyond that attributable to chance, were 0.409 in women not known to have breast cancer, 0.472 in women with diagnosed breast cancer, and 0.493 for all women with p less than .0001 for all three categories. To our knowledge, this is the first report presenting measures of agreement made systematically, simultaneously, and on a continuing basis, during a screening program for quality assurance.     

Bayerisches Mammographiescreening (BMS)

In Bavaria since the 1st April 2003 we have been conducting a high quality mammography-screening carried out in individual practises (BMS). We have used the European and the S 3 guidelines. The best diagnosis is an early diagnosis of the breast carcinoma to save human life. Because of this and the high mortality rate due to this disease it is essential to have a mammogram screening program. There is no single one ideal way of constructing a screening program, it is always based on compromise within the particular health care-systems. Arising problems cannot be avoided, it is only possible when all parties work closely together that the BMS works properly.     

¿Son los sistemas de inteligencia artificial una herramienta útil para los programas de cribado de cáncer de mama?

Population-based breast cancer screening programs are efficacious in reducing the mortality due to breast cancer. These programs use mammography to screen the women who are invited to participate. Digital mammography makes it possible to develop computer-assisted diagnosis (CAD) systems that promise to reduce the workload of radiologists participating in screening programs. However, various studies have shown that CAD results in a high rate of false positive diagnoses. Systems based on artificial intelligence are being more widely implemented, and studies have shown that these systems have better diagnostic performance than traditional CAD systems.This article explains the fundamentals of artificial intelligence systems and an overview of possible applications of these systems within the framework of breast cancer screening programs.     

Voraussetzungen für ein erfolgreiches Lungenkrebsscreeningprogramm

The American national lung cancer screening trial (NLST) has provided the first confirmation of a reduction in lung cancer mortality by using low-dose multislice computed tomography (MSCT). Preliminary evaluations of smaller European trials could not confirm such a reduction. The final evaluation of the larger Dutch-Belgian NELSON trial and five other European trials are expected within the next 1–2 years. The results of the completed rounds of screening in all these studies indicate that the margin between a positive and a negative benefit-to-harm balance will be narrow. In such a scenario it will be crucial to optimize the definition of the target population for screening as a high-risk group for lung cancer, the quality of screening in terms of high sensitivity and specificity as well as high quality treatment and an effective ongoing control of program quality. Not all healthcare systems are suitable to fulfill these prerequisites.     

The Swedish Two-County Trial twenty years later. Updated mortality results and new insights from long-term follow-up

The benefit of invitation to mammographic screening observed in this trial is maintained as a highly significant 32% reduction in breast cancer mortality. Mammographic screening for breast cancer continues to save lives after up to 20 years. Screening derives this benefit by improving the distribution of tumors diagnosed with respect to prognostic categories based on node status, size, and histology of tumors. There is potential for modern screening programs with shorter interscreening intervals to achieve even greater improvements in prognostic category and greater reductions in breast cancer mortality. Mammography can discriminate a subpopulation of high-risk cases, those displaying casting-type calcifications on the mammogram, among very small tumors, with fundamental implications for diagnosis and treatment.     

Bahcesehir long-term population-based screening compared to National Breast Cancer Registry Data: effectiveness of screening in an emerging country

PURPOSEWe aimed to show the effects of long-term screening on clinical, pathologic, and survival outcomes in patients with screen-detected breast cancer and compare these findings with breast cancer patients registered in the National Breast Cancer Registry Data (NBCRD).METHODSWomen aged 40–69 years, living in Bahcesehir county, Istanbul, Turkey, were screened every 2 years using bilateral mammography. The Bahcesehir National Breast Cancer Registry Data (BMSP) data were collected during a 10-year screening period (five rounds of screening). BMSP data were compared with the NBCRD regarding age, cancer stage, types of surgery, tumor size, lymph node status, molecular subtypes, and survival rates.RESULTSDuring the 10-year screening period, 8758 women were screened with 22621 mammograms. Breast cancer was detected in 130 patients; 51 (39.2%) were aged 40–49 years. The comparison of breast cancer patients in the two programs revealed that BMSP patients had earlier stages, higher breast-conserving surgery rates, smaller tumor size, more frequent negative axillary nodal status, lower histologic grade, and higher ductal carcinoma in situ rates than NBCRD patients (p = 0.001, for all).CONCLUSIONThese results indicate the feasibility of successful population-based screening in middle-income countries.

Breast cancer is the most frequent cancer and cause of cancer-related deaths among Turkish women, as well as globally (1–5). Although the incidence of breast cancer increases every year, mortality rates are decreasing in developed countries because of nationwide screening programs and modern treatment options (5, 6). An invited mammography screening program for women aged between 40 and 69 years revealed a 60% reduction in cancer-related 10-year mortality in a landmark study (7). A systematic review of Myers et al. (8) showed that breast cancer screening reduced mortality by 20% in average-risk women of all age groups. However, this review did not evaluate the differences between annual and biannual mammographic screening.In 2004, the Cancer Control Department of Turkey recommended biannual mammographic screening for women aged 50–69 years, based on European Guidelines. The population of Turkey is relatively young, and almost half of all breast cancer patients in Turkey are younger than 50 years. According to and National Breast Cancer Registry Data (NBCRD) reports, the starting age for mammography screening was set as 40 years. The Bahcesehir Mammographic Screening Program (BMSP) was the first organized population-based 10-year (2009–2019) mammography screening program in Turkey, a middle-income country.Turkish Federation of Breast Diseases Societies started a voluntary data registry program that was provided by breast surgeons working in secondary or tertiary hospitals. This program aimed to collect detailed information of breast cancer patients and to pool comprehensive country-specific breast cancer data. This registry, namely the NBCRD, was the first specified database on breast cancer in the country and was started in 2005, before the BMSP (9). Data from 36 centers were collected for 10 years. However, the cancer registry is a standard database containing general information as defined by the International Agency for Research on Cancer standards.The aim of this study was to show the feasibility of a population-based breast cancer screening program in an emerging, middle-income country, Turkey. The objective of our study was to evaluate the effectiveness of a population-based breast cancer screening program by comparing it with NBCRD data.     

Voluntariado radiológico para apoyar un programa de detección precoz del cáncer de mama en Perú: descripción del proyecto,presentación de los primeros resultados e impresiones

Breast cancer is the second most common cancer in Peruvian women. Due to limitations in national breast cancer screening programs, especially in rural areas, more than 50% of cases of breast cancer in Peru are diagnosed in advanced stages. In collaboration with a local clinic registered as a nongovernmental organization (CerviCusco), RAD-AID International aims to create a sustainable diagnostic structure to improve breast cancer screening in Cuzco. With the support of local, national, and international partners that have collaborated in analyzing radiological resources, raising awareness in the population, acquiring equipment, training clinical staff, and building referral networks, our teams of radiologists, included in the RAD-AID team, have participated in training CerviCusco staff in breast ultrasound, thus enabling additional training for radiology residents through a regulated international collaboration.     

The Patient Perspective on Lung Cancer Screening and Health Disparities

Lung cancer screening is just starting to be implemented across the United States. Challenges to screening include access to care, awareness of the option for screening, stigma and implicit bias that are due to stigmatization of smoking, stigma of race, nihilism with lung cancer diagnosis viewed as a “death sentence,” shared decision making, and underestimation of lung cancer risk. African Americans (AA) have the highest lung cancer mortality rate in the United States despite similar smoking rates as whites. AAs are diagnosed at a later stage, and there is a greater likelihood they will refuse treatment options when diagnosed. Additionally, fewer AAs were found to meet lung cancer screening eligibility criteria compared with whites because of lower tobacco exposure and younger age at time of diagnosis. Outreach and access for lung cancer screening in the AA community and other subpopulations at risk are critical to avoid further increasing disparities in lung cancer morbidity and mortality as lung cancer screening is implemented across the United States. The path forward requires implementing outreach programs and providing lung cancer screening in underserved communities at high risk for lung cancer; consideration of using National Comprehensive Cancer Network guidelines for screening selection criteria, including risk model screening selection; and developing interventions to address stigma, clinician implicit bias, and nihilism.     

Entwicklung der Inzidenz und Mortalität an Brustkrebs

In Germany, breast cancer is still the most frequent cancer site with approximately 45.000 incident cases and 18.000 deaths annually. After a continuous increase of mortality for decades and a short period of stagnation, a decline can be observed since a couple of years. However, this turnaround has not been preceded by an analogous evolution of breast cancer incidence. A similar development can also be observed in other countries. The conditions under which this changing trend has occurred indicate that it might have been caused mainly by better treatment and only to a low extent by altered prevalence of risk factors or the implementation of screening programmes. Due to the expected latency, an influence of organized screening on mortality can be expected only at the end of the 1990s, i.e., at the end of the period for which data is available or later. In the discussion about implementation of quality-controlled screening in Germany, it should be kept in mind that the quality of the entire programme--starting with screening and ending with therapy--will decide to what extent breast cancer mortality can be reduced.     

Breast cancer screening; cost-effective in practice?

The main aim of national breast screening is a reduction in breast cancer mortality. The data on the reduction in breast cancer mortality from three (of the five) Swedish trials in particular gave rise to the expectation that the Dutch programme of 2-yearly screening for women aged 50-70 would produce a 16% reduction in the total population. In all likelihood, many of the years of life gained as a result of screening are enjoyed in good health. According to its critics the actual benefit that can be achieved from the national breast cancer screening programmes is overstated. Considerable benefits have recently been demonstrated in England and Wales. However, the fall was so considerable in such a relatively short space of time that screening (started in 1987) was thought to only have played a small part. As far as the Dutch screening programme is concerned it is still too early to reach any conclusions about a possible reduction in mortality. The first short-term results of the screening are favourable and as good as (or better than) expectations. In Swedish regions where mammographic screening was introduced, a 19% reduction in breast cancer mortality can be estimated at population level, and recently a 20% reduction was presented in the UK. In countries where women are expected to make appointments for screening themselves, the attendance figures are significantly lower and the quality of the process as a whole is sometimes poorer. The benefits of breast cancer screening need to be carefully balanced against the burden to women and to the health care system. Mass breast screening requires many resources and will be a costly service. Cost-effectiveness of a breast cancer screening programme can be estimated using a computer model. Published cost-effectiveness ratios may differ tremendously, but are often the result of different types of calculation, time periods considered, including or excluding downstream cost. The approach of simulation and estimation is here the same for all countries. The effects of a breast-screening program depend on many factors, such as the epidemiology of the disease, the health care system, costs of health care, the quality of the screening programme and the attendance rate. The estimated CE-ratio ranges from 2650 euros per life-year gained in Navarra to 9650 in Germany. Although relatively low incidence levels expected, the CE-ratio in Navarra is most favourable probably due to a relatively unfavourable clinical stage distribution before screening and the increasing incidence. The UK has a screening situation that is almost similar with the Netherlands. Therefore, the CE-ratios of both countries are comparable. The differences between countries make it impossible to set up one uniform screening policy. The theoretical outcomes of the benefit that can be achieved are generally from small-scale trials involving a limited number of experts, persons examined, and areas. On a national scale, with hundreds of professional practitioners, it can be expected to be more difficult to attain uniform quality. Continuous quality control, monitoring and evaluation are therefore crucial.     

Typetesting of physical characteristics of digital mammography systems for screening within the Flemish breast cancer screening programme

To investigate compliance with the acceptance criteria of the European guidelines for quality assurance in breast cancer screening, a typetesting programme of the physical characteristics of digital mammography systems based on direct readout (DR) technology or computed radiography (CR) was organised and executed within the Flemish breast cancer screening programme. While in general image quality/dose characteristics of flat panel DR systems passed the acceptance criteria more easily than CR systems, the slit-scanning direct photon counting system included in present study was outstanding in combining a very low dose with a good image quality. The data obtained up to now indicate the necessity of retuning the AEC for DR systems according to constant contrast to noise ratio (CNR) over the whole range of PMMA thicknesses (20–70 mm) to improve image quality in imaging breasts of large thickness at the cost of higher doses. For the two CR systems which passed the typetesting procedure dose levels do not allow a similar improvement of CNR for thick objects for these systems. The obtained results highlight the importance of the use of high Z target/filter combinations in X-ray generating systems for imaging thick objects to meet the image quality/dose criteria. With respect to image display aspects high-quality 3-megapixel LCD monitors succeeded also in the typetesting procedure in addition to 5-megapixel monitors. However, as zooming and scrolling are necessary for 3-megapixel monitors to get the full resolution capabilities of the image capture system, 5-megapixel monitors are preferred in a busy screening environment.     

Clinical impact of the use of additional ultrasonography in diagnostic breast imaging

The degree of adherence with evidence-based guidelines for the use of breast ultrasonography was determined in clinical practice of radiologists in six hospitals. Additional ultrasonography was performed in 2,272 (53%) of all 4,257 patients referred for mammography. High adherence rates (mean: 95%) were observed for guidelines recommending ultrasonography in patients referred for palpable breast masses and abnormal screening and diagnostic mammograms. Lower adherence rates (mean: 81%, Pearson correlation coefficient = −0.57; p = 0.001) were found for guidelines advising against additional ultrasonography in patients referred for breast symptoms, a known benign abnormality, a family history or anxiety of breast cancer. The overuse of ultrasonography in 442 patients and underuse in 95 patients led to five additional false-positive results. It was concluded that the guidelines seem workable and feasible in clinical practice and that the current daily routine of diagnostic breast imaging corresponded to a great extent to the guidelines proposed.     

The role of the reference radiologist. Estimates of inter-observer agreement and potential delay in cancer detection in the national breast screening study

The Canadian National Breast Screening Study (NBSS) is a randomized controlled trial to assess the effect of screening on breast cancer mortality. The NBSS designated a single reference radiologist who blindly reviewed over the course of the study 5200 randomly selected two-view mammographic examinations of women not known to have breast cancer. He also reviewed 575 screening-detected breast cancer (SBC) cases and 102 interval breast cancer (IBC) cases. All cancers were histologically proven. As a result of the reviews, comments on inter-observer agreement, interpretation, and technical quality were conveyed on an ongoing basis to radiologists appointed to 15 NBSS screening centers. Agreement of the reference radiologist with center radiologists was better for breast cancer cases (kappa = 0.511, P less than .002) than for those not known to have breast cancer (kappa = 0.307, P less than .002). Observer error and technical problems led to delayed detection in 22% of SBCs and 35% of IBCs. Another 11% of SBCs and 58% of IBCs were probably mammographically occult. No similarly comprehensive review of mammography during a screening program has been published. Suggestions arising from the NBSS review were sometimes resisted by center radiologists. Measures are suggested which might facilitate acceptance of recommendations arising from audit mechanisms in mammography screening programs, thereby enhancing opportunities for mammographic excellence.