Mammography-based screening program: preliminary results from a first 2-year round in a Brazilian region using mobile and fixed units

RLH, TBS and ALF made substantial contributions to the conception and design of the article, the acquisition, analysis and interpretation of the data, and drafting of the article. ECM, JSCM and NB made substantial contributions to the conception and design of the study.Background: Breast cancer is the most frequently diagnosed cancer and the leading cause of cancer deaths among women worldwide. The use of mobile mammography units to offer screening to women living in remote areas is a rational strategy to increase the number of women examined. This study aimed to evaluate results from the first 2 years of a government-organized mammography screening program implemented with a mobile unit (MU) and a fixed unit (FU) in a rural county in Brazil. The program offered breast cancer screening to women living in Barretos and the surrounding area. Methods: Based on epidemiologic data, 54 238 women, aged 40 to 69 years, were eligible for breast cancer screening. The study included women examined from April 1, 2003 to March 31, 2005. The chi-square test and Bonferroni correction analyses were used to evaluate the frequencies of tumors and the importance of clinical parameters and tumor characteristics. Significance was set at p < 0.05. Results: Overall, 17 964 women underwent mammography. This represented 33.1% of eligible women in the area. A mean of 18.6 and 26.3 women per day were examined in the FU and MU, respectively. Seventy six patients were diagnosed with breast cancer (41 (54%) in the MU). This represented 4.2 cases of breast cancer per 1000 examinations. The number of cancers detected was significantly higher in women aged 60 to 69 years than in those aged 50 to 59 years (p < 0.001) or 40 to 49 years (p < 0.001). No difference was observed between women aged 40 to 49 years and those aged 50 to 59 years (p = 0.164). The proportion of tumors in the early (EC 0 and EC I) and advanced (CS III and CS IV) stages of development were 43.4% and 15.8%, respectively. Conclusions: Preliminary results indicate that this mammography screening program is feasible for implementation in a rural Brazilian territory and favor program continuation

The relation between socioeconomic and demographic factors and tumour stage in women diagnosed with breast cancer in Denmark, 1983–1999

The authors investigated the association between socioeconomic position and stage of breast cancer at the time of diagnosis in a nationwide Danish study. All 28 765 women with a primary invasive breast cancer diagnosed between 1983 and 1999 were identified in a nationwide clinical database and information on socioeconomic variables was obtained from Statistics Denmark. The risk of being diagnosed with a high-risk breast cancer, that is size >20 mm, lymph-node positive, ductal histology/high histologic grade and hormone receptor negative, was analysed by multivariate logistic regression. The adjusted odds ratio (OR) for high-risk breast cancer was reduced with longer education with a 12% reduced risk (95% confidence interval (CI), 0.80,0.96) in women with higher education and increased with reduced disposable income (low income group: OR, 1.22; 95% CI, 1.10,1.34). There was an urban–rural gradient, with higher risk among rural women (OR 1.10; 95 % CI, 1.02, 1.18) and lower risk among women in the capital suburbs (OR, 0.85; 95% CI, 0.78, 0.93) and capital area (OR, 0.93; 95% CI, 0.84–1.02). These factors were significant only for postmenopausal women, although similar patterns were observed among the premenopausal women, suggesting a subgroup of aggressive premenopausal breast cancers less influenced by socioeconomic factors

Mammographic density in birth cohorts of Danish women: a longitudinal study

BACKGROUND: Breast cancer is the leading malignant disease among western women with incidence increasing over time. High mammographic density is a well-established risk factor for breast cancer. We explored trends in mammographic density across birth cohorts to gain further insight into possible time trends in women’s mammographic density that might explain the historical increase in breast cancer incidence. METHODS: Data derived from two mammography screening programs in Denmark from 1991 to 2001, including on average 41,091 women from Copenhagen and 52,938 women from Funen aged 50–69. Mammographic density was assessed qualitatively (fatty or mixed/dense) by senior screening radiologists. The proportion of women with mixed/dense mammographic density was calculated by age at screening, screening period, and birth cohort. The Generalized Estimating Equations were used to calculate odds ratios and 95% confidence intervals. All statistical tests were two-sided. RESULTS: The proportion of women with mixed/dense mammographic density increased from 45% among women born in the 1920s to 75-80% among women born in the 1940s. In Copenhagen, the age-adjusted odds ratio (95% CI) of mixed/dense mammographic density in women born in 1941–42 was 2.48 (2.22-2.76) compared with women born in 1921–22. In Funen, the age-adjusted odds ratio of mixed/dense mammographic density in women born in 1946–47 was 5.89 (5.32-6.51) compared with women born in 1924–25. Hormone use had a greater impact on mammographic density in birth cohorts of the 1920s compared with those of the 1940s. CONCLUSIONS: We found suggestive evidence of a birth cohort pattern in mammographic density and an attenuated impact of hormone use in younger compared with older birth cohorts suggesting that postmenopausal mammographic density could be linked to changing exposures accumulated over time in women’s lives

As you like it: How the same data can support manifold views of overdiagnosis in breast cancer screening

Overdiagnosis estimates have varied substantially, causing confusion. The discussions have been complicated by the fact that population and study design have varied substantially between studies. To help access the impact of study design choices on the estimates, we compared them on a single population. A cohort study from Funen County, Denmark, recently suggested little (∼1%) overdiagnosis. It followed previously screened women for up to 14 years after screening had ended. Using publically available data from Funen, we recreated the designs from five high‐estimate, highly cited studies from various countries. Selected studies estimated overdiagnosis to be 25–54%. Their designs were adapted only to the extent that they reflect the start of screening in Funen in 1993. The reanalysis of the Funen data resulted in overdiagnosis estimates that were remarkably similar to those from the original high‐estimate age‐period studies, 21–55%. In additional analyses, undertaken to elucidate the effect of the individual components of the study designs, overdiagnosis estimates were more than halved after the most likely changes in the background risk were accounted for and decreased additionally when never‐screened birth cohorts were excluded from the analysis. The same data give both low and high estimates of overdiagnosis, it all depends on the study design. This stresses the need for a careful scrutiny of the validity of the assumptions underpinning the estimates. Age‐period analyses of breast cancer overdiagnosis suggesting very high frequencies of overdiagnosis rested on unmet assumptions. This study showed that overdiagnosis estimates should in the future be requested to adequately control for the background risk and include an informative selection of the studied population to achieve valid and comparable estimates of overdiagnosis. This article is protected by copyright. All rights reserved.This paper derives from discussions between participants of the Methodology and Applications in Evaluation of Service Screening for Cancer Workshop held at Wolfson Institute of Preventive Medicine, Centre for Cancer Prevention, Queen Mary University of London, on 22 and 23 May 2013. The views expressed in this paper, however, are those of the authors and do not necessarily represent the views of the Workshop participants

Danish Quality Database for Mammography Screening

Ellen M Mikkelsen,1 Sisse H Njor,1 Ilse Vejborg2 1Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus N, 2Department of Radiology, Diagnostic Imaging Centre, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark Aim: The Danish Quality Database for Mammography Screening (DKMS) was established in 2007, with the aim to monitor, sustain, and improve the quality of the Danish national breast cancer screening program.Study population: All Danish women aged 50&ndash;69 years who were invited every 2&nbsp;years for breast cancer screening in the nationwide program since July 10, 2007.Main variables: The DKMS consists of data retrieved from the five regional invitation systems, the National Pathology Registry, and the National Registry of Patients. The DKMS covers the entire screening process and includes variables required to determine the following eleven indicators: 1) radiation exposure, 2) participation among invited women and participation within the target population, 3) time between screening and result, 4) screening interval, 5) recall for further diagnostics, 6) interval cancers consisting of women diagnosed with breast cancer between screening rounds, 7) invasive breast tumors, 8) node-negative cancers, 9) invasive tumors &le;10&nbsp;mm, 10) ratio of surgery for benign vs malignant lesions, and 11) breast-conserving therapy.Descriptive data: As of August 10, 2015, the database included data from 888,151 unique women who have been invited to one or more screenings. In the first three screening rounds, 641,835 (round I), 580,452 (round II), and 641,938 (round III) women were invited, and participation increased from 79% to 84%. In the third round, 79% of the screened women received their result within ten working days, 2.7% of the screened women were recalled for further diagnostics, 82% of the women operated for invasive carcinomas were node negative, and 40% of the women had the tumor size of &le;10&nbsp;mm.Conclusion: The DKMS has successfully evaluated the quality of the nationwide Danish breast cancer screening program against international quality standards. The quality of the Danish program complies well with international standards particularly as regards to the clinical aspects. Keywords: breast cancer, screening, epidemiolog

Demographic and comorbidity predictors of adherence to diagnostic colonoscopy in the Danish Colorectal Cancer Screening Program: a nationwide cross-sectional study

Mette Kielsholm Thomsen,1 Morten Rasmussen,2 Sisse Helle Njor,1,3 Ellen Margrethe Mikkelsen1 1Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark; 2Department of Digestive Diseases K, Bispebjerg Hospital, Copenhagen, Denmark; 3Department of Public Health Programs, Randers Regional Hospital, Randers, Denmark Background: Predictors of participation in colorectal cancer screening with a stool sample screening modality have been widely studied, but adherence to subsequent diagnostic colonoscopy after a positive screening test has received less attention. We aimed to determine predictors of adherence to diagnostic colonoscopy in the Danish Colorectal Cancer Screening Program.Methods: We conducted a cross-sectional study using data from National Health Service registries. We included 8,112 individuals invited to screening between March 3, 2014, and August 31, 2014, who had a positive immunochemical fecal occult blood test. Potential predictors were gender, age, region of residence, Charlson Comorbidity Index (CCI) score, specific diseases (cardiovascular disease, chronic pulmonary disease, diabetes, and cancer), and number of prior hospital stays. We estimated prevalence proportion differences (PPDs) for the associations between potential predictors and adherence.Results: Overall, adherence to diagnostic colonoscopy was 88.6%. Adherence was lower in individuals aged 75 years compared with those aged &lt;70 years, PPD=&minus;4.20 (95% confidence interval [CI]: &ndash;6.19; &ndash;2.20). Adherence decreased with a higher level of comorbidity: PPD=&minus;2.30 (95% CI: &ndash;3.87; &ndash;0.74) for a CCI score of 1&ndash;2 and PPD=&minus;9.24 (95% CI: &ndash;12.30; &ndash;6.19) for a CCI score of &ge;3 compared to 0. For specific diseases, adherence was decreased in those with a diagnosis of cardiovascular disease, chronic pulmonary disease, or diabetes, but less for cancer. When comorbidity was measured as number of prior hospital stays, the adjusted PPDs were &ndash;2.41 (95% CI: &ndash;4.43;&ndash;0.39) for one to two stays and &ndash;14.50 (95% CI: &ndash;20.30; &ndash;8.74) for three or more stays compared with no in-hospital stays.Conclusion: Major predictors of nonadherence to diagnostic colonoscopy after a positive immunochemical fecal occult blood test were older age, a CCI score of 1 or more, cardiovascular disease, chronic pulmonary disease, diabetes, and one or more in-hospital stays within the last year. Keywords: adherence, compliance, colorectal cancer, screening and prevention, morbidity, comorbidity&nbsp

Abstract P2-04-03: Can the interval cancer ratio diminish the need for background incidence estimates as a mammography screening programme performance indicator?

Abstract Background: Interval cancers (IC) are cancers that are discovered within the interval between two screening examinations, i.e. they present themselves clinically before the next scheduled screening examination. A mammography screening programme that is run in a population with a high breast cancer incidence can have a high interval cancer rate, and still have as protective an effect as a screening programme with a low IC-rate run in a population with a low breast cancer incidence. The effectiveness of a mammography screening programme is therefore normally evaluated by comparing the IC-rate to the expected breast cancer incidence without screening, i.e. the proportional interval cancer rate. The expected breast cancer incidence in absence of screening, or background incidence is, however, difficult to approximate, as the introduction of a screening program makes it difficult or impossible to find a comparable population group that is not screened. We propose to use a new measure, the number of interval cancers out of the total number of cancers, called the interval cancer ratio, as an alternative measure for the burden of interval cancers in an organized mammography screening programme. We seek to validate this new measure by comparing it to the old measure, the proportional interval cancer rate. Method: We did a systematic review and included studies: 1) covering a service screening programme, 2) with inclusion of women aged 50-69 years, 3) that contained observed data, papers based on modeling only were excluded, 4) that contained data on number of interval cancers and number of women screened, or on interval cancers rate, and 5) that contained information on estimated breast cancer incidence rate of the background population. This resulted in 6 papers describing 12 mammography screening programmes. Results: The IC- ratio in studies including only initial screens, varied from 0.13 to 0.32 while the proportional interval cancer rate varied from 0.24 to 0.55 in the same studies. In studies including only subsequent screens the IC-ratio varied from 0.21 to 0.47 with a proportional interval cancer rate of 0.26 to 0.67. One study with mixed initial and subsequent screens with a majority of initial screens had an IC-ratio of 0.18, whereas the proportional interval cancer rate was 0.33. In the study with a majority of subsequent screens had an IC-ratio was 0.32 and the proportional interval cancer rate was 0.67. There is a strong linear relationship between the interval cancer ratio and the proportional interval cancer rate in initial screens. In subsequent screens the trend is linear but is less obvious. Conclusion: Our main aim with this study was to propose and validate the interval cancer ratio as an alternative measure for the burden of interval cancers. The new measure seems to capture the burden of interval cancers just as well or better than the old measure, without the need for increasingly difficult estimations of background incidence, which makes it a more accessible tool when evaluating mammography screening programme performance. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-04-03.</jats:p

Measuring the burden of interval cancers in long-standing screening mammography programmes

OBJECTIVES: Mammography screening programme sensitivity is evaluated by comparing the interval cancer rate (ICR) with the expected breast cancer incidence without screening, ie. the proportional interval cancer rate (PICR). The PICR is usually found by extrapolating pre-screening incidence rates, whereas ICR is calculated from data available in the screening programmes. As there is no consensus regarding estimation of background incidence, we seek to validate the ICR measure against the PICR. METHODS: Screening data from the three mammography screening programmes of Stockholm, Copenhagen, and Funen in the period 1989-2011 provided data to calculate the ICR. The most commonly described methods of extrapolating pre-screening incidence rates to calculate the PICR were illustrated and PICRs were calculated by year and programme using these different methods and compared with the ICRs. RESULTS: PICRs varied greatly, reaching a difference of 32-34% in Stockholm, 79% in Copenhagen, and 100-106% in Funen between the highest and the lowest value, depending on which method was applied. PICRs exhibited large variations yearly and from programme to programme. ICRs did not vary to the same extent, ranging on average from 0.100 to 0.136 in the first 12-months and between 0.201 and 0.225 in the last 12-months of the two-year period after a negative screen across the three programmes. CONCLUSION: The value of the PICR is hugely influenced by which method is applied, whereas the ICR is calculated purely on data available within programmes. We find that the PICR, the establishing indicator for sensitivity, could preferably be replaced by the ICR