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Background: Screening for malignant melanoma has the potential to reduce morbidity and mortality from the disease through earlier detection, as prognosis is closely associated with the thickness of the lesion at the time of diagnosis. However, there are also potential harms from screening people without skin lesion concerns, such as overdiagnosis of lesions that would never have caused symptoms if they had remained undetected. Overdiagnosis results in harm through unnecessary treatment and the psychosocial consequences of being labelled with a cancer diagnosis. For any type of screening, the benefits must outweigh the harms. Screening for malignant melanoma is currently practised in many countries, and the incidence of the disease is rising sharply, while mortality remains largely unchanged., Objectives: To assess the effects on morbidity and mortality of screening for malignant melanoma in the general population., Search Methods: We searched the following databases up to May 2018: the Cochrane Skin Specialised Register, CENTRAL, MEDLINE, Embase, and LILACS. We also searched five trials registries, checked the reference lists of included and other relevant studies for further references to randomised controlled trials (RCTs), used citation tracking (Web of Science) for key articles, and asked trialists about additional studies and study reports., Selection Criteria: RCTs, including cluster-randomised trials, of screening for malignant melanoma compared with no screening, regardless of screening modality or setting, in any type of population and in any age group where people were not suspected of having malignant melanoma. We excluded studies in people with a genetic disposition for malignant melanoma (e.g. familial atypical mole and melanoma syndrome) and studies performed exclusively in people with previous melanomas., Data Collection and Analysis: We used standard methodological procedures expected by Cochrane. The primary outcomes of this review were total mortality, overdiagnosis of malignant melanoma, and quality of life/psychosocial consequences., Main Results: We included two studies with 64,391 participants. The first study was a randomised trial of an intervention developed to increase the rate of performance of thorough skin self-examination. The intervention group received instructional materials, including cues and aids, a 14-minute instruction video, and a brief counselling session, and at three weeks a brief follow-up telephone call from a health educator, aimed at increasing performance of thorough skin self-examination. The control group received a diet intervention with similar follow-up. The trial included 1356 people, who were recruited from 11 primary care practices in the US between 2000 and 2001. Participant mean age was 53.2 years and 41.7% were men. This study did not report on any of our primary outcomes or the following secondary outcomes: mortality specific to malignant melanoma, false-positive rates (skin biopsies/excisions with benign outcome), or false-negative rates (malignant melanomas diagnosed between screening rounds and up to one year after the last round). All participants were asked to complete follow-up telephone interviews at 2, 6, and 12 months after randomisation.The second study was a pilot study for a cluster-RCT of population-based screening for malignant melanoma in Australia. This pilot trial included 63,035 adults aged over 30 years. The three-year programme involved community education, an education and support component for medical practitioners, and the provision of free skin screening services. The mean age of people attending the skin screening clinics (which were held by primary care physicians in workplaces, community venues, and local hospitals, and included day and evening sessions) was 46.5 years, and 51.5% were men. The study included whole communities, targeting participants over 30 years of age, but information on age and gender of the whole study population was not reported. Study duration was three years (1998 to 2001), and outcomes were measured at the screening clinics during these three years. There was no further follow-up for any outcomes. The control group received no programme. The ensuing, planned cluster randomised trial in 560,000 adults was never carried out due to lack of funding. At the time of this review, there are no published or unpublished data on our prespecified outcomes available, and no results for mortality outcomes from the pilot study are to be expected.The risk of bias in these studies was high for performance bias (blinding study personnel and participants) and high or unclear for detection bias (blinding of outcome assessment). Risk of bias in the other domains was either unclear or low. We were unable to assess the certainty of the evidence for our primary outcomes as planned due to lack of data., Authors' Conclusions: Adult general population screening for malignant melanoma is not supported or refuted by current evidence from RCTs. It therefore does not fulfil accepted criteria for implementation of population screening programmes. This review did not investigate the effects of screening people with a history of malignant melanoma or in people with a genetic disposition for malignant melanoma (e.g. familial atypical mole and melanoma syndrome). To determine the benefits and harms of screening for malignant melanoma, a rigorously conducted randomised trial is needed, which assesses overall mortality, overdiagnosis, psychosocial consequences, and resource use.

Background: Effective breast cancer screening should detect early-stage cancer and prevent advanced disease., Objective: To assess the association between screening and the size of detected tumors and to estimate overdiagnosis (detection of tumors that would not become clinically relevant)., Design: Cohort study., Setting: Denmark from 1980 to 2010., Participants: Women aged 35 to 84 years., Intervention: Screening programs offering biennial mammography for women aged 50 to 69 years beginning in different regions at different times., Measurements: Trends in the incidence of advanced (>20 mm) and nonadvanced (≤20 mm) breast cancer tumors in screened and nonscreened women were measured. Two approaches were used to estimate the amount of overdiagnosis: comparing the incidence of advanced and nonadvanced tumors among women aged 50 to 84 years in screening and nonscreening areas; and comparing the incidence for nonadvanced tumors among women aged 35 to 49, 50 to 69, and 70 to 84 years in screening and nonscreening areas., Results: Screening was not associated with lower incidence of advanced tumors. The incidence of nonadvanced tumors increased in the screening versus prescreening periods (incidence rate ratio, 1.49 [95% CI, 1.43 to 1.54]). The first estimation approach found that 271 invasive breast cancer tumors and 179 ductal carcinoma in situ (DCIS) lesions were overdiagnosed in 2010 (overdiagnosis rate of 24.4% [including DCIS] and 14.7% [excluding DCIS]). The second approach, which accounted for regional differences in women younger than the screening age, found that 711 invasive tumors and 180 cases of DCIS were overdiagnosed in 2010 (overdiagnosis rate of 48.3% [including DCIS] and 38.6% [excluding DCIS])., Limitation: Regional differences complicate interpretation., Conclusion: Breast cancer screening was not associated with a reduction in the incidence of advanced cancer. It is likely that 1 in every 3 invasive tumors and cases of DCIS diagnosed in women offered screening represent overdiagnosis (incidence increase of 48.3%)., Primary Funding Source: None.

Background: A variety of estimates of the benefits and harms of mammographic screening for breast cancer have been published and national policies vary., Objectives: To assess the effect of screening for breast cancer with mammography on mortality and morbidity., Search Methods: We searched PubMed (22 November 2012) and the World Health Organization's International Clinical Trials Registry Platform (22 November 2012)., Selection Criteria: Randomised trials comparing mammographic screening with no mammographic screening., Data Collection and Analysis: Two authors independently extracted data. Study authors were contacted for additional information., Main Results: Eight eligible trials were identified. We excluded a trial because the randomisation had failed to produce comparable groups.The eligible trials included 600,000 women in the analyses in the age range 39 to 74 years. Three trials with adequate randomisation did not show a statistically significant reduction in breast cancer mortality at 13 years (relative risk (RR) 0.90, 95% confidence interval (CI) 0.79 to 1.02); four trials with suboptimal randomisation showed a significant reduction in breast cancer mortality with an RR of 0.75 (95% CI 0.67 to 0.83). The RR for all seven trials combined was 0.81 (95% CI 0.74 to 0.87). We found that breast cancer mortality was an unreliable outcome that was biased in favour of screening, mainly because of differential misclassification of cause of death. The trials with adequate randomisation did not find an effect of screening on total cancer mortality, including breast cancer, after 10 years (RR 1.02, 95% CI 0.95 to 1.10) or on all-cause mortality after 13 years (RR 0.99, 95% CI 0.95 to 1.03).Total numbers of lumpectomies and mastectomies were significantly larger in the screened groups (RR 1.31, 95% CI 1.22 to 1.42), as were number of mastectomies (RR 1.20, 95% CI 1.08 to 1.32). The use of radiotherapy was similarly increased whereas there was no difference in the use of chemotherapy (data available in only two trials)., Authors' Conclusions: If we assume that screening reduces breast cancer mortality by 15% and that overdiagnosis and overtreatment is at 30%, it means that for every 2000 women invited for screening throughout 10 years, one will avoid dying of breast cancer and 10 healthy women, who would not have been diagnosed if there had not been screening, will be treated unnecessarily. Furthermore, more than 200 women will experience important psychological distress including anxiety and uncertainty for years because of false positive findings. To help ensure that the women are fully informed before they decide whether or not to attend screening, we have written an evidence-based leaflet for lay people that is available in several languages on www.cochrane.dk. Because of substantial advances in treatment and greater breast cancer awareness since the trials were carried out, it is likely that the absolute effect of screening today is smaller than in the trials. Recent observational studies show more overdiagnosis than in the trials and very little or no reduction in the incidence of advanced cancers with screening.

Background: General health checks are common elements of health care in some countries. These aim to detect disease and risk factors for disease with the purpose of reducing morbidity and mortality. Most of the commonly used screening tests offered in general health checks have been incompletely studied. Also, screening leads to increased use of diagnostic and therapeutic interventions, which can be harmful as well as beneficial. It is, therefore, important to assess whether general health checks do more good than harm., Objectives: We aimed to quantify the benefits and harms of general health checks with an emphasis on patient-relevant outcomes such as morbidity and mortality rather than on surrogate outcomes such as blood pressure and serum cholesterol levels., Search Methods: We searched The Cochrane Library, the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Effective Practice and Organisation of Care (EPOC) Trials Register, MEDLINE, EMBASE, Healthstar, CINAHL, ClinicalTrials.gov and WHO International Clinical Trials Registry Platform (ICTRP) to July 2012. Two authors screened titles and abstracts, assessed papers for eligibility and read reference lists. One author used citation tracking (Web of Knowledge) and asked trialists about additional studies., Selection Criteria: We included randomised trials comparing health checks with no health checks in adults unselected for disease or risk factors. We did not include geriatric trials. We defined health checks as screening general populations for more than one disease or risk factor in more than one organ system., Data Collection and Analysis: Two authors independently extracted data and assessed the risk of bias in the trials. We contacted authors for additional outcomes or trial details when necessary. For mortality outcomes we analysed the results with random-effects model meta-analysis, and for other outcomes we did a qualitative synthesis as meta-analysis was not feasible., Main Results: We included 16 trials, 14 of which had available outcome data (182,880 participants). Nine trials provided data on total mortality (155,899 participants, 11,940 deaths), median follow-up time nine years, giving a risk ratio of 0.99 (95% confidence interval (CI) 0.95 to 1.03). Eight trials provided data on cardiovascular mortality (152,435 participants, 4567 deaths), risk ratio 1.03 (95% CI 0.91 to 1.17) and eight trials on cancer mortality (139,290 participants, 3663 deaths), risk ratio 1.01 (95% CI 0.92 to 1.12). Subgroup and sensitivity analyses did not alter these findings.We did not find an effect on clinical events or other measures of morbidity but one trial found an increased occurrence of hypertension and hypercholesterolaemia with screening and one trial found an increased occurence of self-reported chronic disease. One trial found a 20% increase in the total number of new diagnoses per participant over six years compared to the control group. No trials compared the total number of prescriptions, but two out of four trials found an increased number of people using antihypertensive drugs. Two out of four trials found small beneficial effects on self-reported health, but this could be due to reporting bias as the trials were not blinded. We did not find an effect on admission to hospital, disability, worry, additional visits to the physician, or absence from work, but most of these outcomes were poorly studied. We did not find useful results on the number of referrals to specialists, the number of follow-up tests after positive screening results, or the amount of surgery., Authors' Conclusions: General health checks did not reduce morbidity or mortality, neither overall nor for cardiovascular or cancer causes, although the number of new diagnoses was increased. Important harmful outcomes, such as the number of follow-up diagnostic procedures or short term psychological effects, were often not studied or reported and many trials had methodological problems. With the large number of participants and deaths included, the long follow-up periods used, and considering that cardiovascular and cancer mortality were not reduced, general health checks are unlikely to be beneficial.

Background: The natural history of screen-detected breast cancers is not well understood. A previous analysis of the incidence change during the introduction of the Norwegian screening programme in the late 1990s suggested that the natural history of many screen-detected invasive breast cancers is to regress spontaneously but the study was possibly confounded by use of hormone replacement therapy in the population. We did a similar analysis of data collected during an earlier period when few women were exposed to hormone replacement therapy., Methods: We compared cumulative breast cancer incidence in age-matched cohorts of women living in seven Swedish counties before and after the initiation of public mammography screening between 1986 and 1990. Women aged 40-49 years were invited to screening every year and women aged 50-74 years were invited every 2 years. A screened group including all women aged 40-69 years (n=328,927) was followed-up for 6 years after the first invitation to the programme. A control group including all women in the same age range (n=317,404) was also followed-up for 6 years--4 years without screening and 2 years when they entered the screening programme. Screening attendance was much the same in both groups (close to 80%). Counts of incident invasive breast cancers were obtained from the Swedish Cancer Registry (in-situ cancers were excluded)., Findings: Before the age-matched controls were invited to be screened at the end of their follow-up period, the 4-year cumulative incidence of invasive breast cancer was significantly higher in the screened group (982 per 100,000) than it was in the control group (658 per 100,000) (relative risk [RR] 1·49, 95% CI 1·41-1·58). Even after prevalence screening in the control group, the screened group had higher 6-year cumulative incidence of invasive breast cancer (1443 per 100,000 vs 1269 per 100,000; RR 1·14, 1·10-1·18)., Interpretation: Because the cumulative incidence among controls did not reach that of the screened group, we believe that many invasive breast cancers detected by repeated mammography screening do not persist to be detected by screening at the end of 6 years, suggesting that the natural course of many of the screen-detected invasive breast cancers is to spontaneously regress., Funding: None., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

The information provided to the public by the NHS Breast Screening Programme has been criticized for lack of balance, omission of information on harms and substantially exaggerated estimates of benefit. These shortcomings have been particularly evident in the various invitation leaflets for breast screening and in the Programme's own 2008 Annual Review, which celebrated 20 years of screening. The debate on screening has been heated after new data published in the last two years questioned the benefit and documented substantial harm. We therefore analysed whether the recent debate and new pivotal data about breast screening has had any impact on the contents of the new 2010 leaflet and on the 2010 Annual Review. We conclude that spokespeople for the Programme have stuck to the beliefs about benefit that prevailed 25 years ago. Concerns about over-diagnosis have not been addressed either and official documents still downplay this most important harm of breast cancer screening.

Background: A variety of estimates of the benefits and harms of mammographic screening for breast cancer have been published and national policies vary., Objectives: To assess the effect of screening for breast cancer with mammography on mortality and morbidity., Search Strategy: We searched PubMed (November 2008)., Selection Criteria: Randomised trials comparing mammographic screening with no mammographic screening., Data Collection and Analysis: Both authors independently extracted data. Study authors were contacted for additional information., Main Results: Eight eligible trials were identified. We excluded a biased trial and included 600,000 women in the analyses. Three trials with adequate randomisation did not show a significant reduction in breast cancer mortality at 13 years (relative risk (RR) 0.90, 95% confidence interval (CI) 0.79 to 1.02); four trials with suboptimal randomisation showed a significant reduction in breast cancer mortality with an RR of 0.75 (95% CI 0.67 to 0.83). The RR for all seven trials combined was 0.81 (95% CI 0.74 to 0.87). We found that breast cancer mortality was an unreliable outcome that was biased in favour of screening, mainly because of differential misclassification of cause of death. The trials with adequate randomisation did not find an effect of screening on cancer mortality, including breast cancer, after 10 years (RR 1.02, 95% CI 0.95 to 1.10) or on all-cause mortality after 13 years (RR 0.99, 95% CI 0.95 to 1.03).Numbers of lumpectomies and mastectomies were significantly larger in the screened groups (RR 1.31, 95% CI 1.22 to 1.42) for the two adequately randomised trials that measured this outcome; the use of radiotherapy was similarly increased., Authors' Conclusions: Screening is likely to reduce breast cancer mortality. As the effect was lowest in the adequately randomised trials, a reasonable estimate is a 15% reduction corresponding to an absolute risk reduction of 0.05%. Screening led to 30% overdiagnosis and overtreatment, or an absolute risk increase of 0.5%. This means that for every 2000 women invited for screening throughout 10 years, one will have her life prolonged and 10 healthy women, who would not have been diagnosed if there had not been screening, will be treated unnecessarily. Furthermore, more than 200 women will experience important psychological distress for many months because of false positive findings. It is thus not clear whether screening does more good than harm. To help ensure that the women are fully informed of both benefits and harms before they decide whether or not to attend screening, we have written an evidence-based leaflet for lay people that is available in several languages on www.cochrane.dk.

Background: Overdiagnosis in cancer screening is the detection of cancer lesions that would otherwise not have been detected. It is arguably the most important harm. We quantified overdiagnosis in the Danish mammography screening programme, which is uniquely suited for this purpose, as only 20% of the Danish population has been offered organised mammography screening over a long time-period., Methods: We collected incidence rates of carcinoma in situ and invasive breast cancer in areas with and without screening over 13 years with screening (1991-2003), and 20 years before its introduction (1971-1990). We explored the incidence increase comparing unadjusted incidence rates and used Poisson regression analysis to compensate for the background incidence trend, variation in age distribution and geographical variation in incidence., Results: For the screened age group, 50 to 69 years, we found an overdiagnosis of 35% when we compared unadjusted incidence rates for the screened and non-screened areas, but after compensating for a small decline in incidence in older, previously screened women. Our adjusted Poisson regression analysis indicated a relative risk of 1.40 (95% CI: 1.35-1.45) for the whole screening period, and a potential compensatory drop in older women of 0.90 (95% CI: 0.88-0.96), yielding an overdiagnosis of 33%, which we consider the most reliable estimate. The drop in previously screened women was only present in one of the two screened regions and was small in absolute numbers., Discussion: One in four breast cancers diagnosed in the screened age group in the Danish screening programme is overdiagnosed. Our estimate for Denmark is lower than that for comparable countries, likely because of lower uptake, lower recall rates and lower detection rates of carcinoma in situ.

Background: A variety of estimates of the benefits and harms of mammographic screening for breast cancer have been published and national policies vary., Objectives: To assess the effect of screening for breast cancer with mammography on mortality and morbidity., Search Strategy: We searched PubMed (November 2008)., Selection Criteria: Randomised trials comparing mammographic screening with no mammographic screening., Data Collection and Analysis: Both authors independently extracted data. Study authors were contacted for additional information., Main Results: Eight eligible trials were identified. We excluded a biased trial and included 600,000 women in the analyses. Three trials with adequate randomisation did not show a significant reduction in breast cancer mortality at 13 years (relative risk (RR) 0.90, 95% confidence interval (CI) 0.79 to 1.02); four trials with suboptimal randomisation showed a significant reduction in breast cancer mortality with an RR of 0.75 (95% CI 0.67 to 0.83). The RR for all seven trials combined was 0.81 (95% CI 0.74 to 0.87). We found that breast cancer mortality was an unreliable outcome that was biased in favour of screening, mainly because of differential misclassification of cause of death. The trials with adequate randomisation did not find an effect of screening on cancer mortality, including breast cancer, after 10 years (RR 1.02, 95% CI 0.95 to 1.10) or on all-cause mortality after 13 years (RR 0.99, 95% CI 0.95 to 1.03).Numbers of lumpectomies and mastectomies were significantly larger in the screened groups (RR 1.31, 95% CI 1.22 to 1.42) for the two adequately randomised trials that measured this outcome; the use of radiotherapy was similarly increased., Authors' Conclusions: Screening is likely to reduce breast cancer mortality. As the effect was lowest in the adequately randomised trials, a reasonable estimate is a 15% reduction corresponding to an absolute risk reduction of 0.05%. Screening led to 30% overdiagnosis and overtreatment, or an absolute risk increase of 0.5%. This means that for every 2000 women invited for screening throughout 10 years, one will have her life prolonged and 10 healthy women, who would not have been diagnosed if there had not been screening, will be treated unnecessarily. Furthermore, more than 200 women will experience important psychological distress for many months because of false positive findings. It is thus not clear whether screening does more good than harm. To help ensure that the women are fully informed of both benefits and harms before they decide whether or not to attend screening, we have written an evidence-based leaflet for lay people that is available in several languages on www.cochrane.dk.

Background: The CONSORT statement specifies the need for a balanced presentation of both benefits and harms of medical interventions in trial reports. However, invitations to screening and newspaper articles often emphasize benefits and downplay or omit harms, and it is known that scientific articles can be influenced by conflicts of interest. We wanted to determine if a similar imbalance occurs in scientific articles on mammography screening and if it is related to author affiliation., Methods: We searched PubMed in April 2005 for articles on mammography screening that mentioned a benefit or a harm and that were published in 2004 in English. Data extraction was performed by three independent investigators, two unblinded and one blinded for article contents, and author names and affiliation, as appropriate. The extracted data were compared and discrepancies resolved by two investigators in a combined analysis. We defined three groups of authors: (1) authors in specialties unrelated to mammography screening, (2) authors in screening-affiliated specialties (radiology or breast cancer surgery) who were not working with screening, or authors funded by cancer charities, and (3) authors (at least one) working directly with mammography screening programmes. We used a data extraction sheet with 17 items described as important benefits and harms in the 2002 WHO/IARC-report on breast cancer screening., Results: We identified 854 articles, and 143 were eligible for the study. Most were original research. Benefits were mentioned more often than harms (96% vs 62%, P < 0.001). Fifty-five (38%) articles mentioned only benefits, whereas seven (5%) mentioned only harms (P < 0.001). Overdiagnosis was mentioned in 35 articles (24%), but was more often downplayed or rejected in articles that had authors working with screening, (6/15; 40%) compared with authors affiliated by specialty or funding (1/6; 17%), or authors unrelated with screening (1/14; 7%) (P = 0.03). Benefits in terms of reduced breast cancer mortality were mentioned in 109 (76%) articles, and was more often provided as a relative risk reduction than an absolute risk reduction, where quantified (45 articles (31%) versus 6 articles (3%) (P < 0.001))., Conclusion: Scientific articles tend to emphasize the major benefits of mammography screening over its major harms. This imbalance is related to the authors' affiliation.

Background: National mammography screening programmes are based on the results of randomised trials, but the quality of these trials has recently been questioned. The Swedish Two-County trial reported a 31% reduction in breast cancer mortality and was instrumental for the introduction of screening in many countries. In this trial, official Swedish health registries were used to identify breast cancers and breast cancer deaths in the study population., Methods: We used data from the same registries to estimate the numbers of breast cancer cases and breast cancer deaths among the included women., Results: Compared to official Swedish statistics we found that 192 breast cancer cases and 43 breast cancer deaths seem to be missing in the main publication of the Two-County trial; we found similar discrepancies in two updates of the trial. These large differences can hardly be explained by random fluctuations in the cancer occurrence., Conclusion: The data reported for the Two-County trial are incomplete. Other data indicate that the mortality results in a recent report were flawed.

Objective: To investigate whether information on mammographic screening presented on websites by interest groups is balanced, is independent of source of funding, and reflects recent findings., Design: Cross sectional study using a checklist with 17 information items., Setting: 27 websites in Scandinavian and English speaking countries., Results: The 13 sites from advocacy groups and the 11 from governmental institutions all recommended mammographic screening, whereas the three from consumer organisations questioned screening (P = 0.0007). All the advocacy groups accepted industry funding, apparently without restrictions. In contrast the three consumer organisations acknowledged the risk of bias related to industry funding, and two of them did not accept such funding at all. Advocacy groups and governmental organisations favoured information items that shed positive light on screening. The major harms of screening, overdiagnosis and overtreatment, were mentioned by only four of these groups, but by all three sites from consumer organisations (P = 0.02). In addition, the chosen information was often misleading or erroneous. The selection of information items for websites did not reflect recent findings, apart from the consumer sites, which were much more balanced and comprehensive than other sites (median of 9 information items v 3 items, P = 0.03)., Conclusions: The information material provided by professional advocacy groups and governmental organisations is information poor and severely biased in favour of screening. Few websites live up to accepted standards for informed consent such as those stated in the General Medical Council's guidelines.