Breast Cancer Screening in Denmark

Jørgensen, Karsten Juhl; Gøtzsche, Peter C; Kalager, Mette; Zahl, Per‐Henrik

doi:10.7326/m16-0270

Cited by 108 publications

(60 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Organized breast cancer screening programs were introduced in Copenhagen in 1991 and became nationalized in late 2007 but were still incomplete in 2014 26. In Denmark, unorganized and opportunistic individual‐based prostate cancer screening initiated by the patient or the doctor was frequently performed using prostate‐specific antigen 27, 28.…”

Section: Discussionmentioning

confidence: 99%

Atrial Fibrillation and Risk of Cancer: A Danish Population‐Based Cohort Study

Vinter

Christesen

Fenger‐Grøn

et al. 2018

JAHA

View full text Add to dashboard Cite

BackgroundAtrial fibrillation (AF) and cancer are frequent diseases worldwide. The timewise association between the diagnosis of AF and a subsequent diagnosis of cancer may clarify whether a mutual cause exists, and may also guide clinicians about time windows of high risk of cancer occurrence.Methods and ResultsWe conducted a population‐based cohort study among 26 222 men and 28 879 women free of AF and cancer at baseline based on the Danish Diet, Cancer and Health study. The participants were followed for the development of AF (the Danish National Patient Registry) and subsequent cancer (the Danish Cancer Registry) until 2013. We used Cox proportional hazard models with new‐onset AF as time‐dependent exposure. The men (median age 56 years) and women (median age 56 years) were followed for medians of 16.7 and 19.6 years, respectively. AF was associated with higher risks of any type of cancer (men: hazard ratio [HR] 1.41, 95% confidence interval [CI], 1.26–1.58; women: HR 1.15, 95% CI, 1.02–1.32), and for men only, lung (HR 1.66, 95% CI, 1.19–2.30), and colorectal cancer (HR 1.37, 95% CI, 1.02–1.85). Within the initial 90 days following the diagnosis of AF, the risks of any type of cancer (men: HR 2.89, 95% CI, 2.10–3.98; women: HR 3.72, 95% CI, 2.49–5.56), lung (men: HR 7.70, 95% CI, 4.34–13.68; women: HR 7.98, 95% CI, 3.96–16.09), and colorectal cancer (men: HR 3.35, 95% CI, 1.03–10.90; women: HR 5.91, 95% CI, 2.44–14.29) were higher for men and women.ConclusionsA diagnosis of AF is associated with a higher incidence rate of cancer among men and women. The cancer incidence rate is particularly elevated within 90 days after the diagnosis of AF.

show abstract

Section: Discussionmentioning

confidence: 99%

Atrial Fibrillation and Risk of Cancer: A Danish Population‐Based Cohort Study

Vinter

Christesen

Fenger‐Grøn

et al. 2018

JAHA

View full text Add to dashboard Cite

show abstract

“…Jørgensen et al . reported that “one in every three women aged 50 to 69 years diagnosed with breast cancer was overdiagnosed.”11 Estimation was only based on rates of non‐advanced tumors because “there was no clear compensatory decrease in the incidence of advanced cancer in older women” ( i.e ., women aged 70 to 84 years). However, almost half of the observations in the age‐group 70–84 years were from women never invited to screening or still invited despite having passed the age of 70 years.…”

Section: Discussionmentioning

confidence: 99%

Benefit-to-harm ratio of the Danish breast cancer screening programme

et al. 2017

View full text Add to dashboard Cite

The primary aim of breast cancer screening is to reduce breast cancer mortality, but screening also has negative side‐effects as overdiagnosis. To evaluate a screening programme, both benefits and harms should be considered. Published estimates of the benefit‐to‐harm ratio, the number of breast cancer deaths prevented divided by the number of overdiagnosed breast cancer cases, varied considerably. The objective of the study was to estimate the benefit‐to‐harm ratio of breast cancer screening in Denmark. The numbers of breast cancer deaths prevented and overdiagnosed cases [invasive and ductal carcinoma in situ (DCIS)] were estimated per 1,000 women aged 50–79, using national published estimates for breast cancer mortality and overdiagnosis, and national incidence and mortality rates. Estimations were made for both invited and screened women. Among 1,000 women invited to screening from age 50 to age 69 and followed until age 79, we estimated that 5.4 breast cancer deaths would be prevented and 2.1 cases overdiagnosed, under the observed scenario in Denmark of a breast cancer mortality reduction of 23.4% and 2.3% of the breast cancer cases being overdiagnosed. The estimated benefit‐to‐harm ratio was 2.6 for invited women and 2.5 for screened women. Hence, 2–3 women would be prevented from dying from breast cancer for every woman overdiagnosed with invasive breast cancer or DCIS. The difference between the previous published ratios and 2.6 for Denmark is probably more a reflection of the accuracy of the underlying estimates than of the actual screening programmes. Therefore, benefit‐to‐harm ratios should be used cautiously.

show abstract

“…There is a clear increase in BC incidence worldwide, concomitant to implementation of mammography [11]. However, this increase has been attributed to overdiagnosis [1,12,13], i.e. detection by screening of cancers that would not go on to cause death or would spontaneously regress [11].…”

Section: Introductionmentioning

confidence: 99%

“…However, the rate of overdiagnosis is disputed and estimates from random clinical trials suggest than less than five percent of cancers are overdiagnosed [14]. In any case, overdiagnosis does not explain the lack of efficacy of mammography in prevention of metastatic disease [6], nor why screening has not led to a reduction in the incidence of advanced BC [13] .…”

Section: Introductionmentioning

confidence: 99%

Breast cancer incidence as a function of the number of previous mammograms: analysis of the NHS screening programme

Corcos

2017

Preprint

View full text Add to dashboard Cite

The discrepancy between the protective effect of early surgery of breast cancer and the poor benefits of mammography screening programs in the long term can be explained if mammography induces breast cancer at a much higher rate than anticipated. Mammography screening is associated in most countries with a higher incidence of breast cancer, attributed to overdiagnosis. X-ray-induced cancers can be distinguished from overdiagnosed cancers by the fact that their incidence depends on the number of previous mammograms, whereas overdiagnosis solely depends on the last screening mammogram, leading to diagnosis. The unbiased relationship between the number of mammograms and breast cancer incidence was evaluated from the data of the NHS Breast Cancer screening programme in women aged from 50 to 64 years in the United Kingdom. The delay between mammography and increased breast cancer incidence was confirmed from the data of the "Age" trial, a randomized trial of annual screening starting at age 40 in the UK. In women aged 50-64 attending screening at the NHS Breast Cancer programme, in situ breast cancer incidence increased linearly from 1993 to 2005 as a function of the number of mammograms. Incidence did not increase anymore after 2005 when the number of mammograms and the delay after screening was stable. Invasive breast cancer incidence increased more specifically in the 60-69 age group. The risk of breast cancer almost doubled after 15 years of screening. Additional cancers began to occur less than 6 years after mammography. These results are evidence that X-ray-induced carcinogenesis, rather than overdiagnosis, is the cause of the increase in breast cancer incidence.

show abstract

Breast Cancer Screening in Denmark

Abstract: None.

Cited by 108 publications

References 23 publications

Atrial Fibrillation and Risk of Cancer: A Danish Population‐Based Cohort Study

Atrial Fibrillation and Risk of Cancer: A Danish Population‐Based Cohort Study

Benefit-to-harm ratio of the Danish breast cancer screening programme

Breast cancer incidence as a function of the number of previous mammograms: analysis of the NHS screening programme

Contact Info

Product

Resources

About