Extra incidence caused by mammographic screening

Boer, R. de; Warmerdam, Peter G.; Koning, Harry J. de; Oortmarssen, Gerrit van

doi:10.1016/s0140-6736(94)90105-8

Cited by 61 publications

(60 citation statements)

References 2 publications

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“…The degree of over-diagnosis remains controversial, with estimates varying from 2 to 54% of extra breast cancer incidence due to organized screening. 25,26 In our study, the influence of screening would probably be apparent in estimates for age-groups commonly targeted for screening (50-69 years). 27 In principle, our Further limitations apply to our study: We were not able to stratify our analyses according to histological subtype or topographical sub-site.…”

Section: Discussionmentioning

confidence: 85%

Excess of cancers in Europe: A study of eleven major cancers amenable to lifestyle change

Soerjomataram

Vries

Pukkala

et al. 2006

Intl Journal of Cancer

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Worldwide an estimated 11 million cancer cases were diagnosed in 2002, one quarter being in Europe. We estimated the potential in avoidable numbers and proportions of 11 cancers amenable to prevention (cancers of the oral cavity, oesophagus, stomach, colorectal, pancreas, laryngeal, lung, female breast, endometrium, kidney and bladder) in 28 European countries. We assumed that the aggregated rate of 3 countries with lowest incidence to be attainable throughout Europe. The difference between the age-and gender-specific national cancer incidence rates and the lowest rate observed in 2002 was determined and defined as ''avoidable.'' Of the 1.4 million adult cases of selected cancers and countries within our study, 363,000 (59%) cancers in males and 326,000 (45%) cancers in females were hypothetically avoidable. Among men, the proportion was largest in Hungary (77%) and among women, in Belgium (54%). Assuming that differences in cancer incidence are not attributable to genetic susceptibility or diagnostic activity, about 50% of all cases of these 11 cancers could be potentially avoided, especially by decreased smoking among men. Interventions directed at reducing smoking, obesity and alcohol use as well as increasing physical activity and fruit and vegetable intake are necessary to attain lower incidence rates. It is important to recognize that the actual preventable cancer by eliminating currently known risk factors is somewhat less than we have estimated. ' 2006 Wiley-Liss, Inc.

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Section: Discussionmentioning

confidence: 85%

Excess of cancers in Europe: A study of eleven major cancers amenable to lifestyle change

Soerjomataram

Vries

Pukkala

et al. 2006

Intl Journal of Cancer

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“…The classical lead-time adjustment method includes all cancers diagnosed in a long time period after screening has stopped (10-15 years) in both the screening and the control group when comparing cumulative hazard rates. 7 This ratio is initially equal to the excess-incidence estimate, but rapidly approaches zero difference between the two groups with increasing follow-up. 2 Another leadtime approach is using a multistage statistical model where all tumors are assumed to grow (but with different speed), which estimates overdiagnosis as the fraction of tumors detected at screening that would never become clinical during the lifetime of the patient.…”

Section: Why the Lead-time Approach Is Misleadingmentioning

confidence: 93%

“…a Breast cancer incidence with screening (red line) as predicted with the MISCAN model, which is a lead-time model. 7 The blue line is the no screening group. b Observed breast cancer incidence rates for Norwegian women in the period 1991-1995 before screening started (blue line), and for a cohort of 70,000 Norwegian women aged 50 years invited to biennial screening (first screening in 1996-2001) with 10 years follow-up (solid red line).…”

Section: Lifetime Risk Of Overdiagnosismentioning

confidence: 99%

Lead-Time Models Should Not Be Used to Estimate Overdiagnosis in Cancer Screening

2014

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Lead-time can mean two different things: Clinical leadtime is the lead-time for clinically relevant tumors; that is, those that are not overdiagnosed. Model-based leadtime is a theoretical construct where the time when the tumor would have caused symptoms is not limited by the person's death. It is the average time at which the diagnosis is brought forward for both clinically relevant and overdiagnosed cancers. When screening for breast cancer, clinical lead-time is about 1 year, while modelbased lead-time varies from 2 to 7 years. There are two different methods to calculate overdiagnosis in cancer screening-the excess-incidence approach and the lead-time approach-that rely on two different leadtime definitions. Overdiagnosis when screening with mammography has varied from 0 to 75 %. We have explained that these differences are mainly caused by using different definitions and methods and not by variations in data. High levels of overdiagnosis of cancer have usually been explained by detection of many slowgrowing tumors with long lead-times. This theory can be tested by studying if slow-growing tumors accumulate in the absence of screening, which they don't. Thus, it is likely that the natural history of many subclinical cancers is spontaneous regression. E tzioni et al. 1 have recently compared the two different methods to calculate overdiagnosis in breast and prostate cancer screening: the excess-incidence approach and the lead-time approach. They write that the main limitations of the excess-incidence approach are that the prevalence screening rounds are included and that followup after screening is insufficient, whereas the lead-time approach relies on model choices and assumptions that are not transparent. They conclude that they "wonder whether it is possible to compare and integrate results across published studies of overdiagnosis". Etzioni et al. 1 do not state which approach they consider most reliable. We have recently published a comparison of the two approaches. 2 We concluded that the excess-incidence approach is preferable. The lead-time approach seriously underestimates overdiagnosis because of flawed assumptions about how much screening advances the time of diagnosis. 2 It is generally accepted that prostate specific antigen (PSA) screening for prostate cancer leads to about 50 % overdiagnosis, which means that one in three prostate cancers in a population offered screening are overdiagnosed. This estimate is based on the excessincidence approach applied to the randomized trials. 1 Using the same approach, we calculated 31 % overdiagnosis in randomized trials of mammography screening; 3 in observational studies, we found 30-50 % overdiagnosis of invasive breast cancer in countries with publicly organized screening programs. 4,5 WHY THE EXCESS-INCIDENCE APPROACH IS PREFERABLEWith the excess-incidence approach, the reduction in the number of cancers after screening has stopped is subtracted from the incidence increase observed during screening. With long follow-up after screening has stopped, this...

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“…It is important to realise that the initial increase does not signify overdiagnosis, but that it is the result of the necessary downstaging of breast cancer diagnoses, if screening will be effective. Several authors concluded that overdiagnosis might be limited to a few percent (Boer et al, 1994;Olsen et al, 2003;Yen et al, 2003;Paci et al, 2004). It is likely that besides organised screening and the general tendency towards earlier detection (increased awareness, spontaneous mammography) other factors, such as declining fertility rates and the widespread use of hormone replacement therapy, contribute to the observed increase in breast cancer incidence (Prehn et al, 2002;Beral, 2003;Coebergh, 2003;Li et al, 2003).…”

Section: %mentioning

confidence: 99%

Decreased rates of advanced breast cancer due to mammography screening in The Netherlands

et al. 2004

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The effect of the implementation of the Dutch breast cancer screening programme during 1990 -1997 on the incidence rates of breast cancer, particularly advanced breast cancer, was analysed according to stage at diagnosis in seven regions, where no screening took place before 1990. The Netherlands Cancer Registry provided detailed data on breast cancer incidence in 1989 -1997 by tumour stage, age and region. Annual age-adjusted incidence rates of all breast cancers and advanced cancers, defined as large tumours T2 þ with lymph node and/or distant metastases, were compared with rates in 1989. In general, breast cancer incidence rose strongly in the early 1990s, especially in the age category 50 -69 years (estimated annual percentage change (EAPC) 4.25; 95% CI 1.70, 6.86). The increase was mainly due to the increase in small T1 cancers and ductal carcinoma in situ. However, in women aged 50 -69, advanced cancer incidence rates showed a significant decline by 12.1% in 1997 compared with 1989 (EAPC -2.14, 95% CI À3.47, À0.80), followed by a breast cancer mortality reduction of similar size after approximately 2 years. We confirm that breast cancer screening initially leads to a temporary strong increase in the breast cancer incidence, which is followed by a significant decrease in advanced diseases in the women invited for screening. It is evident that breast cancer screening contributes to a reduction in advanced breast cancers and breast cancer mortality.

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Extra incidence caused by mammographic screening

Cited by 61 publications

References 2 publications

Excess of cancers in Europe: A study of eleven major cancers amenable to lifestyle change

Excess of cancers in Europe: A study of eleven major cancers amenable to lifestyle change

Lead-Time Models Should Not Be Used to Estimate Overdiagnosis in Cancer Screening

Decreased rates of advanced breast cancer due to mammography screening in The Netherlands

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