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Elsebeth Lynge

Publications and source records attributed to Elsebeth Lynge.

At least 19 recordsLinked to original sources

Performance of clinical mammography: a nationwide study from Denmark.

Clinical mammography is the key tool for breast cancer diagnosis, but little is known about the impact of the organisational set-up on the performance. We evaluated whether organisational factors influence the performance of clinical mammography. Clinical mammography data from all clinics in Denmark in the year 2000 were collected and linked to cancer outcome. Use of the National Institute of Radiation Hygiene register for identification of radiology clinics ensured comprehensive nationwide registration. We used the final mammographic assessment at the end of the imaging work-up to determine sensitivity, specificity and accuracy, the latter using a receiver-operating characteristics (ROC) analysis. In 96,534 clinical mammography examinations, sensitivity was 75% and specificity 99%. The presence of at least one high volume-reading radiologist in the clinic increased accuracy (AUC = 0.91 for <1,000 examinations/year and 0.92 for >2,000 examinations/year, p = 0.017). The examination volume per clinic showed no clear effect on performance, as accuracy was significantly higher in clinics with a medium number of examinations (AUC = 0.93 for 2,000-4,000 examinations/year and 0.90 for >6,000 examinations/year, p = 0.003). Accuracy was significantly lower in regions with high annual utilisation rate of clinical mammography, which means the proportion of examined women in a region (AUC = 0.90 for 3.0-5.0% annual utilisation rate and AUC = 0.93 for 2.0-2.5% annual utilisation rate, and p = 0.001), indicating that clinical mammography worked best in patient populations of purely symptomatic women. Our data indicate that to increase the accuracy of clinical mammography at the community level, the presence of an experienced radiologist should be prioritized ahead of raising the clinic size.

Adult↗

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

BACKGROUND: 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. METHODS: Denmark has 2 regional screening programs targeting women ages 50 years to 69 years. The programs were initiated in 1991 and 1993, respectively. No screening takes place in the 13 other Danish regions. Data regarding incident breast cancers detected between 1979 and 2001 were retrieved from the Danish Cancer Registry for each screening region and for the rest of Denmark, and time trends in rates for women ages 50 years to 69 years were compared. From 1 program, individual screening data were used to analyze breast cancer incidence in women who were never screened, those who were screened for the first time, or those who previously were screened. RESULTS: The incidence of breast cancer was found to have increased regardless of screening. In the screening regions, a marked prevalence peak was observed, and the incidence hereafter was compatible with the level indicated by the 95% confidence limits for the regression curves for the rates in the prescreening period, taking into account the artificial ageing in the program, the influx of newcomers, and variations in the data. Women who had undergone previous screening were found to have the same incidence of breast cancer as women who were never screened. CONCLUSIONS: The data from the current study do not provide evidence of overdiagnosis of invasive breast cancer in the 2 Danish screening programs or, if overdiagnosis was found to occur, it was only of limited magnitude.

Age Factors↗

A pooled analysis of bladder cancer case-control studies evaluating smoking in men and women.

OBJECTIVE: A recent study suggested that risk of bladder cancer may be higher in women than in men who smoked comparable amounts of cigarettes. We pooled primary data from 14 case-control studies of bladder cancer from Europe and North America and evaluated differences in risk of smoking by gender. METHODS: The pooled analysis included 8316 cases (21% women) and 17,406 controls (28% women) aged 30-79 years. Odds ratios (ORs) and 95% confidence intervals (95% CI) for smoking were adjusted for age and study. Exposure-response was evaluated in a stratified analysis by gender and by generalized additive models. RESULTS: The odds ratios for current smokers compared to nonsmokers were 3.9 (95% CI 3.5-4.3) for males and 3.6 (3.1-4.1) for females. In 11 out of 14 studies, ORs were slightly higher in men. ORs for current smoking were similar for men (OR = 3.4) and women (OR = 3.7) in North America, while in Europe men (OR = 5.3) had higher ORs than women (OR = 3.9). ORs increased with duration and intensity in both genders and the exposure-response patterns were remarkably similar between genders. CONCLUSION: These results do not support the hypothesis that women have a higher relative risk of smoking-related bladder cancer than men.

Adult↗

Women's patterns of participation in mammography screening in Denmark.

The objective of the study is to analyse individual women's participation patterns in mammography screening in Denmark. The study is set in the capital of Copenhagen and the county of Fyn representing around 95,000 women aged 50-69. The Central Population Register (CPR) was used to define the total target group, and supply information on migrations and deaths. Invitation and participation data came from the mammography screening programmes in Copenhagen (1991-1999) and Fyn (1993-2001), containing personal identification number, data on invitation date, participation and examination date for each screening round. In Copenhagen the coverage went from 70.5% in the first round to 63.1% in the fourth round, and the equivalent data for Fyn is 84.6% in the first round and 82.8% in the fourth round. Of the women eligible for at least three invitation rounds, 52.6% in Copenhagen and 76.4% in Fyn were faithful users, i.e. had participated in all screenings they were invited to. The conclusion is that the programme participation rates tend to overestimate the protection of the individual women covered by the programme. Behind the urban-rural gradient in programme participation is an even greater gradient in programme protection.

Aged↗

Breast cancer incidence and mortality in the Nordic capitals, 1970-1998. Trends related to mammography screening programmes.

The aim of the present study was to relate the time trends in breast cancer incidence and mortality to the introduction of mammography screening in the Nordic capitals. Helsinki offered screening to women aged 50-59 starting in 1986. The other three capitals offered screening to women aged 50-69 starting in 1989 in Stockholm, 1991 in Copenhagen, and 1996 in Oslo. Prevalence peaks in breast cancer incidence depended on the age groups covered by the screening, the length of the implementation of screening, and the extent of background opportunistic screening. No mortality reduction following the introduction of screening was visible after seven to 12 years of screening in any of the three capitals where significant effects of the screening on the breast cancer mortality had already been demonstrated by using other analytical methods for the evaluation. No visible effect on mortality reduction was expected in Oslo due to too short an observation period. The study showed that the population-based breast cancer mortality trend is too crude a measure to detect the effect of screening on breast cancer mortality during the first years after the start of a programme.

Age Factors↗

Causes of death behind low life expectancy of Danish women.

AIMS: The authors examined causes of death contributing to the relatively high mortality of Danish women born 1915-45, and evaluated the impact of smoking related causes of death. METHODS: Age-period-cohort analysis of mortality of Danish women aged 40-89 in 1960-98. Estimate of the negative curvature in parabola patterns for 50 causes of death. RESULTS: A total of 34 causes of death contributed to the relatively high mortality for women born 1915-45. The main contribution came from smoking-related causes of death. CONCLUSION: The results indicate a high smoking prevalence to be the main explanation behind the relatively low life expectancy of Danish women born 1915-45.

Aged↗

Do changes in lymph node status distribution explain trends in survival of breast cancer patients in Denmark?

We studied the impact on survival of changes in breast cancer patients' distribution by lymph node status at the time of diagnosis. Our study included breast cancer patients diagnosed from 1978 to 1994 in Denmark, where the treatment schemes for breast cancer patients were fairly stable, and where mammography screening was limited. We measured lymph node status by the proportion of positive lymph nodes of all excised lymph nodes, as assessed by a pathologist. This measure was available for two-thirds of the breast cancer patients. The outcome was 5-year relative survival. Changes in lymph node status distribution explained half of the improvement in 5-year relative survival, and seem to be the single most important cause behind the improved survival of breast cancer patients in Denmark.

Aged↗

Performance of combined clinical mammography and needle biopsy: a nationwide study from Denmark.

Clinical mammography and needle biopsy are key tools for non-operative assessment of breast lesions. We evaluated the performance of all combined tests undertaken in Denmark in 2000. Clinical mammography and needle biopsy data were collected and linked to final cancer outcome, to determine sensitivity, specificity, and predictive values of clinical mammography, needle biopsy, and combined test. In 2000, 6709 combined tests were performed in 36 mammography clinics in Denmark. The combined test was consistently more sensitive than any single test, increasing the proportion of women correctly identified with breast cancer by 9% compared with clinical mammography alone. For concordant combined tests (i.e. either both benign or both malignant), specificity and positive predictive value were 100%, sensitivity was 99.1%, and positive predictive value was 99.6%. Therefore, Danish patients with a malignant concordant combined test can proceed directly to definitive surgery without fear of a false-positive diagnosis, and Danish women with a concordant benign combined test can omit surgery without fear of a false-negative diagnosis. In discordant cases, our results showed that any of the two tests with a suspicious or malignant result indicated a high risk of cancer, and excisional diagnostic biopsy therefore still has an important role to play.

Adult↗

What happens when organization of cervical cancer screening is delayed or stopped?

OBJECTIVES: Many countries rely on opportunistic screening, and data on its effectiveness are asked for. We assessed the impact on cervical cancer incidence and mortality of opportunistic screening compared with organized screening. SETTING: Women aged 30-64 in Denmark, 1973-2002; 16 counties with different screening strategies. METHODS: Cumulative incidence and mortality rates for women aged 30-64 by county. Poisson regression of incidence and mortality rates by age, calendar period and county. Interaction between type of county and calendar period measured the difference between counties with screening organized early versus late in time. RESULTS: A statistically significant interaction was found between type of county and calendar period (P=0.0151) for cervical cancer incidence, but not for cervical cancer mortality (P=0.9593). The interaction terms were not statistically significant when a comparison was made between a single county in which an organized programme was interrupted for an 11-year period and other counties. There was, however, a statistically significant increased incidence and mortality rates at the restart of the organized programme. CONCLUSION: Organization of cervical cancer screening accelerated the decline in cervical cancer incidence, compared with the trend in areas relying on opportunistic screening. No impact could be measured of the screening organization on cervical cancer mortality. A decade long stop of an organized screening programme was associated with a temporary increase in cervical cancer incidence and mortality. Coverage remains a key quality indicator in the ongoing modernization of screening technology.

Adult↗

Cancer in persons working in dry cleaning in the Nordic countries.

U.S. studies have reported an increased risk of esophageal and some other cancers in dry cleaners exposed to tetrachloroethylene. We investigated whether the U.S. findings could be reproduced in the Nordic countries using a series of case-control studies nested in cohorts of laundry and dry-cleaning workers identified from the 1970 censuses in Denmark, Norway, Sweden, and Finland. Dry-cleaning work in the Nordic countries during the period when tetrachloroethylene was the dominant solvent was not associated with an increased risk of esophageal cancer [rate ratio (RR) = 0.76; 95% confidence interval (CI), 0.34-1.69], but our study was hampered by some unclassifiable cases. The risks of cancer of the gastric cardia, liver, pancreas, and kidney and non-Hodgkin lymphoma were not significantly increased. Assistants in dry-cleaning shops had a borderline significant excess risk of cervical cancer not found in women directly involved in dry cleaning. We found an excess risk of bladder cancer (RR = 1.44; 95% CI, 1.07-1.93) not associated with length of employment. The finding of no excess risk of esophageal cancer in Nordic dry cleaners differs from U.S. findings. Chance, differences in level of exposure to tetrachloroethylene, and confounding may explain the findings. The overall evidence on bladder cancer in dry cleaners is equivocal.

Case-Control Studies↗

Cancer mortality in workers exposed to organochlorine compounds in the pulp and paper industry: an international collaborative study.

The objective of this study was to evaluate cancer mortality in pulp and paper industry workers exposed to chlorinated organic compounds. We assembled a multinational cohort of workers employed between 1920 and 1996 in 11 countries. Exposure to both volatile and nonvolatile organochlorine compounds was estimated at the department level using an exposure matrix. We conducted a standardized mortality ratio (SMR) analysis based on age and calendar-period-specific national mortality rates and a Poisson regression analysis. The study population consisted of 60,468 workers. Workers exposed to volatile organochlorines experienced a deficit of all-cause [SMR = 0.91; 95% confidence interval (CI), 0.89-0.93] and all-cancer (SMR = 0.93; 95% CI, 0.89-0.97) mortality, with no evidence of increased risks for any cancer of a priori interest. There was a weak, but statistically significant, trend of increasing risk of all-cancer mortality with increasing weighted cumulative exposure. A similar deficit in all-cause (SMR = 0.94; 95% CI, 0.91-0.96) and all-cancer (SMR = 0.94; 95% CI, 0.89-1.00) mortality was observed in those exposed to nonvolatile organochlorines. No excess risk was observed in cancers of a priori interest, although mortality from Hodgkin disease was elevated (SMR = 1.76; 95% CI, 1.02-2.82) . In this study we found little evidence that exposure to organochlorines at the levels experienced in the pulp and paper industry is associated with an increased risk of cancer, apart from a weak but significant association between all-cancer mortality and weighted cumulative volatile organochlorine exposure.

Humans↗

European multi-centre case-control study on risk factors for rare cancers of unknown aetiology.

To search for occupational risk factors, we conducted a case-control study in nine European countries of cancers of the small intestine, male gall bladder, thymus, bone, male breast, melanoma of the eye, and mycosis fungoides. Recruitment was population based in Denmark, Latvia, France, Germany, Italy, and Sweden, from hospital areas in Spain and Portugal, and from one United Kingdom (UK) hospital. We recruited 1457 cases (84% interviewed). Numbers identified corresponded to those in the EUROCIM database for Denmark, but were below those observed for France, Italy and Sweden in the database. We recruited 3374 population (61% interviewed) and 1284 colon cancer controls (86% interviewed). It was possible to undertake this complicated study across Europe, but we encountered three main problems. It was difficult to ensure complete case ascertainment, for population controls, we found a clear divide in the response rate from 75% in the South to only 55% in the North, and a somewhat selective recruitment was noted for the colon cancer controls. The study showed there is a clear dose-response relationship between alcohol intake and the risk of male breast cancer, and an excess risk of mycosis fungoides among glass formers, pottery and ceramic workers. Further data are expected.

Adult↗

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.

Adult↗

Breast cancer mortality in Copenhagen after introduction of mammography screening: cohort study.

OBJECTIVES: To evaluate the effect on breast cancer mortality during the first 10 years of the mammography service screening programme that was introduced in Copenhagen in 1991. DESIGN: Cohort study. SETTING: The mammography service screening programme in Copenhagen, Denmark. PARTICIPANTS: All women ever invited to mammography screening in the first 10 years of the programme. Historical, national, and historical national control groups were used. MAIN OUTCOME MEASURES: The main outcome measure was breast cancer mortality. We compared breast cancer mortality in the study group with rates in the control groups, adjusting for age, time period, and region. RESULTS: Breast cancer mortality in the screening period was reduced by 25% (relative risk 0.75, 95% confidence interval 0.63 to 0.89) compared with what we would expect in the absence of screening. For women actually participating in screening, breast cancer mortality was reduced by 37%. CONCLUSIONS: In the Copenhagen programme, breast cancer mortality was reduced without severe negative side effects for the participants.

Aged↗

Occupational risks for uveal melanoma results from a case-control study in nine European countries.

OBJECTIVE: Uveal melanoma is a rare disease with poor prognosis and largely unknown etiology. We studied potential occupational risk factors. METHODS: A population based case-control study was undertaken during 1995-1997 in nine European countries using population and colon cancer controls with personal interviews. Occupational exposure to sunlight and artificial UV radiation was assessed with a job exposure matrix. In total, 320 uveal melanoma cases were eligible at pathology review, and 292 cases were interviewed, participation 91%. Out of 3357 population controls, 2062 were interviewed, 61%, and out of 1272 cancer controls 1094 were interviewed, 86%. RESULTS: Using population controls, occupational exposure to sunlight was not associated with an increased risk (RR=1.24, 95% CI=0.88-1.74), while an excess risk found with use of colon cancer controls was attributed to confounding factors. An excess risk in welders was restricted to the French part of the data. Cooks, RR=2.40; cleaners, RR 2.15; and laundry workers, RR=3.14, were at increased risk of uveal melanoma. CONCLUSION: Our study does overall not support an association between occupational sunlight exposure and risk of uveal melanoma. The finding of an excess risk of eye melanoma in cooks in several European countries is intriguing.

Adult↗

A model for determining the effect of mammography service screening.

In an overview, Swedish mammography screening trials demonstrated a 29% reduction in breast cancer mortality in women aged 50-69 and no effect on total mortality. Three Danish regions introduced mammography screening in the 1990s. The authors developed a method to evaluate the effect of mammography service screening on breast cancer mortality and validated it applying it to total mortality, where no effect was expected. Study groups and historical and national control groups were analysed using Poisson regression. Total mortality in the screening regions and periods was close to that expected in the absence of screening. A small (3%) excess risk, also seen in a non-screening area, probably results from regional differences changing over time. The effect of this is inseparable from the screening effect. The design is adequate for analysing the effect of mammography service screening on breast cancer mortality.

Aged↗