The Canadian National Breast Screening Study-1: Breast Cancer Mortality after 11 to 16 Years of Follow-up: A Randomized Screening Trial of Mammography in Women Age 40 to 49 Years

Miller, Anthony B.; To, Teresa; Baines, Cornelia J.; Wall, Claus

doi:10.7326/0003-4819-137-5_part_1-200209030-00005

Cited by 367 publications

(255 citation statements)

References 21 publications

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“…[2][3][4] Furthermore, Otto et al 5,6 showed that the Dutch population-based screening programme is effective in reducing breast cancer mortality. The evidence for the benefit of mammography screening for younger women is less conclusive, [7][8][9] however, an effect for this age group is supported by several studies. Although the UK Age Trial showed a non-significant 17% reduction in breast cancer mortality, 9 a statistically significant breast cancer mortality reduction of 15% to 18% associated with screening for women aged 39 to 49 or 40 to 49 at entry was demonstrated by several meta-analyses of randomised controlled trials.…”

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confidence: 99%

Cost‐effectiveness of digital mammography screening before the age of 50 in The Netherlands

Sankatsing

Heijnsdijk

Luijt

et al. 2015

Intl Journal of Cancer

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In the Netherlands, routine mammography screening starts at age 50. This starting age may have to be reconsidered because of the increasing breast cancer incidence among women aged 40 to 49 and the recent implementation of digital mammography. We assessed the cost-effectiveness of digital mammography screening that starts between age 40 and 49, using a microsimulation model. Women were screened before age 50, in addition to the current programme (biennial 50-74). Screening strategies varied in starting age (between 40 and 50) and frequency (annual or biennial). The numbers of breast cancers diagnosed, life-years gained (LYG) and breast cancer deaths averted were predicted and incremental cost-effectiveness ratios (ICERs) were calculated to compare screening scenarios. Biennial screening from age 50 to 74 (current strategy) was estimated to gain 157 life years per 1,000 women with lifelong follow-up, compared to a situation without screening, and cost e3,376/ LYG (3.5% discounted). Additional screening increased the number of LYG, compared to no screening, ranging from 168 to 242. The costs to generate one additional LYG (i.e., ICER), comparing a screening strategy to the less intensive alternative, were estimated at e5,329 (biennial 48-74 vs. current strategy), e7,628 (biennial 45-74 vs. biennial 48-74), e10,826 (biennial 40-74 vs. biennial 45-74) and e18,759 (annual 40-49 1 biennial 50-74 vs. biennial 40-74). Other strategies (49 1 biennial 50-74 and annual 45-49 1 biennial 50-74) resulted in less favourable ICERs. These findings show that extending the Dutch screening programme by screening between age 40 and 49 is cost-effective, particularly for biennial strategies.Breast cancer is the most commonly diagnosed form of cancer among women aged 30 and older in the Netherlands. 1 Mammography screening allows for early detection and early treatment of breast cancer, with the aim of averting breast cancer death. In the Netherlands, women aged 50 to 74 are invited biennially to screening. Various randomised controlled trials demonstrated a statistically significant breast cancer mortality reduction due to mammography screening in this age group. 2-4 Furthermore, Otto et al. 5,6 showed that the Dutch population-based screening programme is effective in reducing breast cancer mortality. The evidence for the benefit of mammography screening for younger women is less conclusive, 7-9 however, an effect for this age group is supported by several studies. Although the UK Age Trial showed a non-significant 17% reduction in breast cancer mortality, 9 a statistically significant breast cancer mortality reduction of 15% to 18% associated with screening for women aged 39 to 49 or 40 to 49 at entry was demonstrated by several meta-analyses of randomised controlled trials. [10][11][12][13] In addition, a recent Swedish observational study that compared breast cancer mortality rates between women aged 40 and 49 who were invited to screening and women who were not invited to screening demonstrated a 26% statistically significant br...

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mentioning

confidence: 99%

Cost‐effectiveness of digital mammography screening before the age of 50 in The Netherlands

Sankatsing

Heijnsdijk

Luijt

et al. 2015

Intl Journal of Cancer

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“…The Canadian NBSS1 trial, which was designed to compare the effect of screening by mammography and physical examination with an initial physical examination only in women aged 40 -49 at entry, has suffered from low statistical power, and has also been criticised for the use of a volunteer population and doubts about the quality of mammography. After 11 -16 years of follow-up, this trial has shown no difference in breast cancer mortality between the two arms (Miller et al, 2002).…”

Section: Discussionmentioning

confidence: 85%

Randomised controlled trial of mammographic screening in women from age 40: results of screening in the first 10 years

et al. 2005

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Debate continues over the effectiveness of screening by mammography in women below age 50. We report here on results of screening in the first 10 years of a randomised trial to study the effect on breast cancer mortality of invitation to annual mammography from age 40 to 41 compared to first invitation to the 3-yearly UK national programme at age 50 -52. The trial is taking place in 23 NHS breast screening centres. Between 1991 and 1997, 160 921 women were randomised in the ratio 1 : 2 to intervention and control arms. Screening is by two views at first screen and single view subsequently; data on screening up to and including round five are now complete. Uptake of invitation to screening is between 68 and 70% at all but the latest screening rounds. Rates of referral for assessment are 4.6% at first screen and 3.4% at subsequent screens. Invasive cancer detection rates are 0.09% at first screen, and similar at rescreens until the sixth and later screens. There is little evidence of regular mammography in the trial control arm. The setting of this trial within the NHS breast screening programme should ensure applicability of results to a national programme.

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“…The reductions in breast cancer mortality varied from 20% in the Marmot report12 to 32% from the Two County Study 13. This reflected that the Marmot report used all RCTs, including the two Canadian outliers,15, 16 and that the Two County Study was the single RCT with the largest reduction in breast cancer mortality. The proportion of overdiagnosed cases varied from 2.3% in the Danish data to 15.6% in the Norwegian data.…”

Section: Discussionmentioning

confidence: 99%

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

et al. 2017

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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.

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The Canadian National Breast Screening Study-1: Breast Cancer Mortality after 11 to 16 Years of Follow-up: A Randomized Screening Trial of Mammography in Women Age 40 to 49 Years

Cited by 367 publications

References 21 publications

Cost‐effectiveness of digital mammography screening before the age of 50 in The Netherlands

Cost‐effectiveness of digital mammography screening before the age of 50 in The Netherlands

Randomised controlled trial of mammographic screening in women from age 40: results of screening in the first 10 years

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

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