My von Euler-Chelpin

Socio-demographic determinants of participation in mammography screening

Our objective was to use individual data on socio‐demographic characteristics to identify predictors of participation in mammography screening and control to what extent they can explain the regional difference. We used data from mammography screening programmes in Copenhagen, 1991–1999, and Funen, 1993–2001, Denmark. Target groups were identified from the Population Register, screening data came from the health authority, and socio‐demographic data from Statistics Denmark. Included were women eligible for at least 3 screens. The crude RR of never use versus always use was 3.21 (95%CI, 3.07–3.35) for Copenhagen versus Funen, and the adjusted RR was 2.55 (95%CI, 2.43–2.67). The adjusted RR for never use among women without contact to a primary care physician was 2.50 (95% CI, 2.31–2.71) and 2.89 (95% CI, 2.66–3.14), and for women without dental care 2.94 (95% CI, 2.77–3.12) and 2.88 (95% CI, 2.68–3.10) for Copenhagen and Funen, respectively. Other important predictive factors for nonparticipation were not being married and not being Danish. In conclusion, to enhance participation in mammography screening programmes special attention needs to be given to women not using other primary health care services. All women in Copenhagen, irrespective of their socio‐demographic characteristics, had low participation. Screening programmes have to find ways to handle this urbanity factor.

Determinants of participation in colorectal cancer screening with faecal occult blood testing

BACKGROUND Colorectal cancer is one of the most common cancers in men and women. Participation rates in faecal occult blood testing (FOBT) screening activities are, however, relatively low. In terms of lowering the colorectal cancer mortality, high participation rates are essential, and therefore it is important to understand the barriers to FOBT screening. METHODS We undertook a systematic search through PUBMED, Medline, EMBASE and PsycINFO in order to identify studies that provide information on socio-demographic determinants of participation in FOBT screening. RESULTS FOBT participation varied considerably across countries, but they have rarely been above 60%. The use of other health-care services was in most studies a strong determinant for participation in screening with FOBT. There was a tendency to higher participation among women than among men and among married as opposed to not married, but determinants varied across countries and test settings. There was no systematic variation in participation across age groups. CONCLUSION The participation pattern depends in part on local circumstances, which makes it difficult to point to a general strategy for increasing the uptake in FOBT screening. This stresses the need for monitoring of individual screening programmes and developing information strategies targeted to the local participation pattern.

Do nonattenders in mammography screening programmes seek mammography elsewhere

The objectives of our study were to analyse the use of diagnostic mammography among nonattenders and attenders in organised mammography screening in Denmark in 2000, to assess the contamination from organised screening of noninvited age groups and to measure the impact of local policy on opportunistic screening. Data on all diagnostic mammographies performed in Denmark in 2000 and data on women targeted by the 2 organised mammography screening programmes in Copenhagen and the county of Fyn were collected. All data were linked by the Danish personal identification number. Information on the official policy in 2000 with regard to opportunistic screening was collected from all counties. The proportion of women using diagnostic mammography was only 1–3% for both attenders and nonattenders in organised mammography screening, but it was significantly higher in Copenhagen than in Fyn, due to availability of mammography in private clinics. The proportion of women using diagnostic mammography varied from 1–4% across counties. The official policy on access to diagnostic mammography and contamination from organised mammography screening of adjacent age groups had no impact on the use. Instead, urbanisation was positively correlated with use of diagnostic mammography. In conclusion, our results clearly showed that nonattenders in organised mammography screening programmes do not seek mammography outside the programme. Since a positive policy toward opportunistic screening did not have any effect, our results add further evidence to existing knowledge that the only reasonable way to achieve high mammography coverage is through a well‐organised screening programme.

Variation in detection of ductal carcinoma in situ during screening mammography: a survey within the International Cancer Screening Network

BACKGROUND There is concern about detection of ductal carcinoma in situ (DCIS) in screening mammography. DCIS accounts for a substantial proportion of screen-detected lesions but its effect on breast cancer mortality is debated. The International Cancer Screening Network conducted a comparative analysis to determine variation in DCIS detection. PATIENTS AND METHODS Data were collected during 2004-2008 on number of screening examinations, detected breast cancers, DCIS cases and Globocan 2008 breast cancer incidence rates derived from national or regional cancer registers. We calculated screen-detection rates for breast cancers and DCIS. RESULTS Data were obtained from 15 screening settings in 12 countries; 7,176,050 screening examinations; 29,605 breast cancers and 5324 DCIS cases. The ratio between highest and lowest breast cancer incidence was 2.88 (95% confidence interval (CI) 2.76-3.00); 2.97 (95% CI 2.51-3.51) for detection of breast cancer; and 3.49 (95% CI 2.70-4.51) for detection of DCIS. CONCLUSIONS Considerable international variation was found in DCIS detection. This variation could not be fully explained by variation in incidence nor in breast cancer detection rates. It suggests the potential for wide discrepancies in management of DCIS resulting in overtreatment of indolent DCIS or undertreatment of potentially curable disease. Comprehensive cancer registration is needed to monitor DCIS detection. Efforts to understand discrepancies and standardise management may improve care.

Condom use in prevention of Human Papillomavirus infections and cervical neoplasia: systematic review of longitudinal studies

Objectives Based on cross-sectional studies, the data on protection from Human Papillomavirus (HPV) infections related to using male condoms appear inconsistent. Longitudinal studies are more informative for this purpose. We undertook a systematic review of longitudinal studies on the effectiveness of male condoms in preventing HPV infection and cervical neoplasia. Methods We searched PubMed using MeSH terms for articles published until May 2013. Articles were included if they studied a change in non-immunocompromized women’s cervical HPV infection or cervical lesion status along with the frequency of condom use. Results In total, 384 abstracts were retrieved. Eight studies reported in 10 articles met the inclusion criteria for the final review. Four studies showed a statistically significantly protective effect of consistent condom use on HPV infection and on regression of cervical neoplasia. In the remaining four studies, a protective effect was also observed for these outcomes, although it was not statistically significant. Conclusions Consistent condom use appears to offer a relatively good protection from HPV infections and associated cervical neoplasia. Advice to use condoms might be used as an additional instrument to prevent unnecessary colposcopies and neoplasia treatments in cervical screening, and to reduce the risk of cervical cancer.

Breast cancer incidence after the introduction of mammography screening: what should be expected?

A prevalence peak is expected in breast cancer incidence when mammography screening begins, but afterward the incidence still may be elevated compared with prescreening levels. It is important to determine whether this is due to overdiagnosis (ie, the detection of asymptomatic disease that would otherwise not have arisen clinically). In the current study, the authors examined breast cancer incidence after the introduction of mammography screening in Denmark.

Comparing sensitivity and specificity of screening mammography in the United States and Denmark

Delivery of screening mammography differs substantially between the United States (US) and Denmark. We evaluated whether there are differences in screening sensitivity and specificity. We included screens from women screened at age 50–69 years during 1996–2008/2009 in the US Breast Cancer Surveillance Consortium (BCSC) (n = 2,872,791), and from two population‐based mammography screening programs in Denmark (Copenhagen, n = 148,156 and Funen, n = 275,553). Women were followed‐up for 1 year. For initial screens, recall rate was significantly higher in BCSC (17.6%) than in Copenhagen (4.3%) and Funen (3.1%). Sensitivity was fairly similar in BCSC (91.8%) and Copenhagen (90.5%) and Funen (92.5%). At subsequent screens, recall rates were 8.8%, 1.8% and 1.4% in BCSC, Copenhagen and Funen, respectively. The BCSC sensitivity (82.3%) was lower compared with that in Copenhagen (88.9%) and Funen (86.9%), but when stratified by time since last screen, the sensitivity was similar. For both initial and subsequent screenings, the specificity of screening in BCSC (83.2% and 91.6%) was significantly lower than that in Copenhagen (96.6% and 98.8%) and Funen (97.9% and 99.2%). By taking time since last screen into account, it was found that American and Danish women had the same probability of having their asymptomatic cancers detected at screening. However, the majority of women free of asymptomatic cancers experienced more harms in terms of false‐positive findings in the US than in Denmark.

Balancing sensitivity and specificity: Sixteen year's of experience from the mammography screening programme in Copenhagen, Denmark

AIM To report on sensitivity and specificity from 7 invitation rounds of the organised, population-based mammography screening programme started in Copenhagen, Denmark, in 1991, and offered biennially to women aged 50-69. Changes over time were related to organisation and technology. METHODS Individualized data were retrieved on outcome of screening mammography, assessment, surgery, and interval cancers. European Guideline performance indicators were calculated, supplemented with false positive and interval cancer rates per 1000 screens. False positive tests were divided into those sorted out at assessment (Type 1) and at surgery (Type 2). RESULTS In total, 1392 invasive breast cancers/ductal carcinoma in situ cases (DCIS) were diagnosed, giving an overall detection rate of 7.6 per 1000 screens. Of 5178 false positive tests, 4666 were Type 1 and 512 Type 2. The 468 interval cancers constituted 25% of all breast cancers (=screen detected+interval cancer). Almost all outcome measures were well within the desirable level of the European Guidelines. Risk of Type 2 false positive tests was positively associated with detection rate especially at initial screen, and interval cancer rate was negatively associated with detection rate. This association was decoupled after introduction of high resolution ultrasound and stereotactic breast biopsies, resulting in a Benign-to-Malignant-Ratio (BMR) of 1:11.40. CONCLUSION Mammography screening is a delicate balance between benefits and risks. Increase in detection rate came at cost of increase in risk of benign biopsies. Introduction of new technologies broke this pattern and a slight increase in detection rate coincided with an unprecedentedly low BMR.

Participation in mammography screening among migrants and non-migrants in Denmark

Background. Inequality in use of mammography screening across population groups is a concern since migrants are more likely to become non-users compared to the general population. The aim of this study was to a) identify determinants of participation among migrant groups and Danish-born women with emphasis on the effect of household size, socioeconomic position and use of healthcare services, and b) test whether effects of determinants were consistent across migrant and non-migrant groups. Material and methods. We used data from the first eight invitation rounds of the mammography screening programme in Copenhagen, Denmark (1991–2008) in combination with register-based data. Results. The crude odds ratio (OR) for not participating in mammography screening was 1.38 (95% CI, 1.30–1.46) for women born in other-Western and 1.80 (95% CI, 1.71–1.90) for women born in non-Western countries compared to Danish-born women. The adjusted OR was 1.14 (95% CI, 1.06–1.21) for other-Western and 1.19 (95% CI, 1.11–1.27) for women born in non-Western countries. Lack of contact with a general practitioner or dental services, and not being employed had a significant negative effect on use of mammography screening. Higher-educated women were significantly less likely to use mammo-graphy screening in all groups whilst hospitalisation had a significant effect among Danish-born women. Living alone was consistently associated with non-use of mammography screening. The probability of becoming a non-user was significantly less among women living within households of two to four persons compared to women living alone. Except in the case of age and hospitalisation, trends were similar across country of birth, but the relative importance of specific determinants in explaining use of mammography screening differed. Conclusion. Household size, socioeconomic position and use of healthcare services were determinants of participation in mammography screening. This study emphasises the need for conducting refined analyses distinguishing among subgroups within diverse populations when explaining differences in screening behaviour.

Risk of Breast Cancer After False-Positive Test Results in Screening Mammography

BACKGROUND Screening for disease in healthy people inevitably leads to some false-positive tests in disease-free individuals. Normally, women with false-positive screening tests for breast cancer are referred back to routine screening. However, the long-term outcome for women with false-positive tests is unknown. METHODS We used data from a long-standing population-based screening mammography program in Copenhagen, Denmark, to determine the long-term risk of breast cancer in women with false-positive tests. The age-adjusted relative risk (RR) of breast cancer for women with a false-positive test compared with women with only negative tests was estimated with Poisson regression, adjusted for age, and stratified by screening round and technology period. All statistical tests were two-sided. RESULTS A total of 58 003 women, aged 50-69 years, were included in the analysis. Women with negative tests had an absolute cancer rate of 339/100 000 person-years at risk, whereas women with a false-positive test had an absolute rate of 583/100 000 person-years at risk. The adjusted relative risk of breast cancer after a false-positive test was 1.67 (95% confidence interval [CI] 1.45 to 1.88). The relative risk remained statistically significantly increased 6 or more years after the false-positive test, with point estimates varying between 1.58 and 2.30. When stratified by assessment technology phase and using equal follow-up time, the false-positive group from the mid 1990s had a statistically significantly higher risk of breast cancer (RR = 1.65, 95% CI = 1.22 to 2.24) than the group with negative tests, whereas the false-positive group from the early 2000s was not statistically significantly different from the group testing negative. CONCLUSIONS The implementation of new assessment technology coincided with a decrease in the size of excess risk of breast cancer for women with false-positive screening results. However, it may be beneficial to actively encourage women with false-positive tests to continue to attend regular screening.