Possible net harms of breast cancer screening: updated modelling of Forrest report.
Ontology highlight
ABSTRACT: Objective
To assess the claim in a Cochrane review that mammographic breast cancer screening could be doing more harm than good by updating the analysis in the Forrest report, which led to screening in the United Kingdom.Design
Development of a life table model, which replicated Forrest's results before updating and extending them with data from relevant systematic reviews, trials, and other models based on purposive literature searches.Participants
Women aged 50 and over invited for breast cancer screening.Main outcome measures
Quality adjusted life years (QALYs), combining life years gained from screening with losses of quality of life from false positive diagnoses and surgery.Results
Inclusion of the effects of harms reduced the updated estimate of net cumulative QALYs gained after 20 years from 3301 to 1536 or by more than half. The best estimates from the Cochrane review generated negative QALYs for the first seven years of screening, 70 QALYs after 10 years, and 834 QALYs after 20 years. Sensitivity analysis showed these results were robust to a range of assumptions, particularly up to 10 years. It also indicated the importance of the level and duration of harms from surgery.Conclusions
This analysis supports the claim that the introduction of breast cancer screening might have caused net harm for up to 10 years after the start of screening.
SUBMITTER: Raftery J
PROVIDER: S-EPMC3234304 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:ObjectiveTo investigate whether information on mammographic screening presented on websites by interest groups is balanced, is independent of source of funding, and reflects recent findings.DesignCross sectional study using a checklist with 17 information items.Setting27 websites in Scandinavian and English speaking countries.ResultsThe 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).ConclusionsThe 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.
| S-EPMC314513 | biostudies-literature
Project description:PREDICT Breast ( www.breast .predict.nhs.uk ) is a prognostication tool for early invasive breast cancer. The current version was based on cases diagnosed in 1999-2003 and did not incorporate the benefits of radiotherapy or the harms associated with therapy. Since then, there has been a substantial improvement in the outcomes for breast cancer cases. The aim of this study was to update PREDICT Breast to ensure that the underlying model is appropriate for contemporary patients. Data from the England National Cancer Registration and Advisory Service for invasive breast cancer cases diagnosed 2000-17 were used for model development and validation. Model development was based on 35,474 cases diagnosed and registered by the Eastern Cancer Registry. A Cox model was used to estimate the prognostic effects of the year of diagnosis, age at diagnosis, tumour size, tumour grade and number of positive nodes. Separate models were developed for ER-positive and ER-negative disease. Data on 32,408 cases from the West Midlands Cancer Registry and 100,551 cases from other cancer registries were used for validation. The new model was well-calibrated; predicted breast cancer deaths at 5-, 10- and 15-year were within 10 per cent of the observed validation data. Discrimination was also good: The AUC for 15-year breast cancer survival was 0.809 in the West Midlands data set and 0.846 in the data set for the other registries. The new PREDICT Breast model outperformed the current model and will be implemented in the online tool which should lead to more accurate absolute treatment benefit predictions for individual patients.
| S-EPMC10789872 | biostudies-literature
Project description:ObjectiveTo calculate the changes in harms and benefits of cervical cancer screening over the first three screening rounds of the Dutch high-risk human papillomavirus (hrHPV) screening programme.DesignMicrosimulation study.SettingDutch hrHPV screening programme; women are invited for screening every 5 or 10 years (depending on age and screening history) from age 30 to 65.PopulationPartly vaccinated population of 100 million Dutch women.MethodsMicrosimulation model MISCAN was used to estimate screening effects. Sensitivity analyses were performed on test characteristics and attendance.Main outcome measuresHarms (screening tests, unnecessary referrals, treatment-related health problems), benefits (CIN2+ diagnoses) and programme efficiency (number needed to screen [NNS]) over the first (period 2017-2021), second (period 2022-2026) and third (period 2027-2031) rounds of hrHPV-based screening.ResultsThe number of screening tests and CIN2+ diagnoses decreased from the first to the second round (-25.8% and -23.6%, respectively). In the third screening round, these numbers decreased further, albeit only slightly (-2.7% and -5.3%, respectively). NNS to detect a CIN2+ remained constant over the rounds; however, it increased in younger age groups while decreasing in older age groups.ConclusionBoth harms and benefits of hrHPV screening decreased over the first screening rounds. For younger women, the efficiency would decrease, whereas longer screening intervals would lead to increased efficiency in older women. Programme efficiency overall remained stable, showing the importance of longer intervals for low-risk women.Tweetable abstractCervical cancer screening: both harms and benefits of hrHPV screening will decrease in the future.
| S-EPMC9541905 | biostudies-literature
Project description:BackgroundHuman papillomavirus (HPV) vaccination and intensifying screening expedite cervical cancer (CC) elimination, yet also deteriorate the balance between harms and benefits of screening. We aimed to find screening strategies that eliminate CC rapidly but maintain an acceptable harms-benefits ratio of screening.MethodsTwo microsimulation models (STDSIM and MISCAN) were applied to simulate HPV transmission and CC screening for the Dutch female population between 2022 and 2100. We estimated the CC elimination year and harms-benefits ratios of screening for 228 unique scenarios varying in vaccination (coverage and vaccine type) and screening (coverage and number of lifetime invitations in vaccinated cohorts). The acceptable harms-benefits ratio was defined as the number of women needed to refer (NNR) to prevent one CC death under the current programme for unvaccinated cohorts (82.17).ResultsUnder current vaccination conditions (bivalent vaccine, 55% coverage in girls, 27.5% coverage in boys), maintaining current screening conditions is projected to eliminate CC by 2042, but increases the present NNR with 41%. Reducing the number of lifetime screens from presently five to three and increasing screening coverage (61% to 70%) would prevent an increase in harms and only delay elimination by 1 year. Scaling vaccination coverage to 90% in boys and girls with the nonavalent vaccine is estimated to eliminate CC by 2040 under current screening conditions, but exceeds the acceptable NNR with 23%. Here, changing from five to two lifetime screens would keep the NNR acceptable without delaying CC elimination.ConclusionsDe-intensifying CC screening in vaccinated cohorts leads to little or no delay in CC elimination while it substantially reduces the harms of screening. Therefore, de-intensifying CC screening in vaccinated cohorts should be considered to ensure acceptable harms-benefits ratios on the road to CC elimination.
| S-EPMC9645325 | biostudies-literature
Project description:BACKGROUND:Controversy persists about optimal mammography screening strategies. OBJECTIVE:To evaluate screening outcomes, taking into account advances in mammography and treatment of breast cancer. DESIGN:Collaboration of 6 simulation models using national data on incidence, digital mammography performance, treatment effects, and other-cause mortality. SETTING:United States. PATIENTS:Average-risk U.S. female population and subgroups with varying risk, breast density, or comorbidity. INTERVENTION:Eight strategies differing by age at which screening starts (40, 45, or 50 years) and screening interval (annual, biennial, and hybrid [annual for women in their 40s and biennial thereafter]). All strategies assumed 100% adherence and stopped at age 74 years. MEASUREMENTS:Benefits (breast cancer-specific mortality reduction, breast cancer deaths averted, life-years, and quality-adjusted life-years); number of mammograms used; harms (false-positive results, benign biopsies, and overdiagnosis); and ratios of harms (or use) and benefits (efficiency) per 1000 screens. RESULTS:Biennial strategies were consistently the most efficient for average-risk women. Biennial screening from age 50 to 74 years avoided a median of 7 breast cancer deaths versus no screening; annual screening from age 40 to 74 years avoided an additional 3 deaths, but yielded 1988 more false-positive results and 11 more overdiagnoses per 1000 women screened. Annual screening from age 50 to 74 years was inefficient (similar benefits, but more harms than other strategies). For groups with a 2- to 4-fold increased risk, annual screening from age 40 years had similar harms and benefits as screening average-risk women biennially from 50 to 74 years. For groups with moderate or severe comorbidity, screening could stop at age 66 to 68 years. LIMITATION:Other imaging technologies, polygenic risk, and nonadherence were not considered. CONCLUSION:Biennial screening for breast cancer is efficient for average-risk populations. Decisions about starting ages and intervals will depend on population characteristics and the decision makers' weight given to the harms and benefits of screening. PRIMARY FUNDING SOURCE:National Institutes of Health.
| S-EPMC5079106 | biostudies-literature
Project description:BackgroundA paucity of research addresses breast cancer screening strategies for women at lower-than-average breast cancer risk. The aim of this study was to examine screening harms and benefits among women aged 50-74 years at lower-than-average breast cancer risk by breast density.MethodsThree well-established, validated Cancer Intervention and Surveillance Network models were used to estimate the lifetime benefits and harms of different screening scenarios, varying by screening interval (biennial, triennial). Breast cancer deaths averted, life-years and quality-adjusted life-years gained, false-positives, benign biopsies, and overdiagnosis were assessed by relative risk (RR) level (0.6, 0.7, 0.85, 1 [average risk]) and breast density category, for US women born in 1970.ResultsScreening benefits decreased proportionally with decreasing risk and with lower breast density. False-positives, unnecessary biopsies, and the percentage overdiagnosis also varied substantially by breast density category; false-positives and unnecessary biopsies were highest in the heterogeneously dense category. For women with fatty or scattered fibroglandular breast density and a relative risk of no more than 0.85, the additional deaths averted and life-years gained were small with biennial vs triennial screening. For these groups, undergoing 4 additional screens (screening biennially [13 screens] vs triennially [9 screens]) averted no more than 1 additional breast cancer death and gained no more than 16 life-years and no more than 10 quality-adjusted life-years per 1000 women but resulted in up to 232 more false-positives per 1000 women.ConclusionTriennial screening from age 50 to 74 years may be a reasonable screening strategy for women with lower-than-average breast cancer risk and fatty or scattered fibroglandular breast density.
| S-EPMC8502479 | biostudies-literature
Project description:This systematic review, stimulated by inconsistency in secondary evidence, reports the benefits and harms of breast cancer (BC) screening and their determinants according to systematic reviews. A systematic search, which identified 9,976 abstracts, led to the inclusion of 58 reviews. BC mortality reduction with screening mammography was 15-25% in trials and 28-56% in observational studies in all age groups, and the risk of stage III+ cancers was reduced for women older than 49 years. Overdiagnosis due to mammography was 1-60% in trials and 1-12% in studies with a low risk of bias, and cumulative false-positive rates were lower with biennial than annual screening (3-17% vs 0.01-41%). There is no consistency in the reviews' conclusions about the magnitude of BC mortality reduction among women younger than 50 years or older than 69 years, or determinants of benefits and harms of mammography, including the type of mammography (digital vs screen-film), the number of views and the screening interval. Similarly, there was no solid evidence on determinants of benefits and harms or BC mortality reduction with screening by ultrasonography or clinical breast examination (sensitivity ranges, 54-84% and 47-69%, respectively), and strong evidence of unfavourable benefit-to-harm ratio with breast self-examination. The reviews' conclusions were not dependent on the quality of the reviews or publication date. Systematic reviews on mammography screening, mainly from high-income countries, systematically disagree on the interpretation of the benefit-to-harm ratio. Future reviews are unlikely to clarify the discrepancies unless new original studies are published.
| S-EPMC6619055 | biostudies-literature
Project description:BackgroundCancer screening should be recommended only when the balance between benefits and harms is favorable. This review evaluated how U.S. cancer screening guidelines reported harms, within and across organ-specific processes to screen for cancer.ObjectiveTo describe current reporting practices and identify opportunities for improvement.DesignReview of guidelines.SettingUnited States.PatientsPatients eligible for screening for breast, cervical, colorectal, lung, or prostate cancer according to U.S. guidelines.MeasurementsInformation was abstracted on reporting of patient-level harms associated with screening, diagnostic follow-up, and treatment. The authors classified harms reporting as not mentioned, conceptual, qualitative, or quantitative and noted whether literature was cited when harms were described. Frequency of harms reporting was summarized by organ type.ResultsHarms reporting was inconsistent across organ types and at each step of the cancer screening process. Guidelines did not report all harms for any specific organ type or for any category of harm across organ types. The most complete harms reporting was for prostate cancer screening guidelines and the least complete for colorectal cancer screening guidelines. Conceptualization of harms and use of quantitative evidence also differed by organ type.LimitationsThis review considers only patient-level harms. The authors did not verify accuracy of harms information presented in the guidelines.ConclusionThe review identified opportunities for improving conceptualization, assessment, and reporting of screening process-related harms in guidelines. Future work should consider nuances associated with each organ-specific process to screen for cancer, including which harms are most salient and where evidence gaps exist, and explicitly explore how to optimally weigh available evidence in determining net screening benefit. Improved harms reporting could aid informed decision making, ultimately improving cancer screening delivery.Primary funding sourceNational Cancer Institute.
| S-EPMC9903969 | biostudies-literature
Project description:ObjectivesTo assess how often harm is quantified in randomised trials of cancer screening.DesignTwo authors independently extracted data on harms from randomised cancer screening trials. Binary outcomes were described as proportions and continuous outcomes with medians and interquartile ranges.Data sourcesFor cancer screening previously assessed in a Cochrane review, we identified trials from their reference lists and updated the search in CENTRAL. For cancer screening not assessed in a Cochrane review, we searched CENTRAL, Medline, and Embase.Eligibility criteria for selecting studiesRandomised trials that assessed the efficacy of cancer screening for reducing incidence of cancer, cancer specific mortality, and/or all cause mortality.Data extractionTwo reviewers independently assessed articles for eligibility. Two reviewers, who were blinded to the identity of the study's authors, assessed whether absolute numbers or incidence rates of outcomes related to harm were provided separately for the screening and control groups. The outcomes were false positive findings, overdiagnosis, negative psychosocial consequences, somatic complications, invasive follow-up procedures, all cause mortality, and withdrawals because of adverse events.ResultsOut of 4590 articles assessed, 198 (57 trials, 10 screening technologies) matched the inclusion criteria. False positive findings were quantified in two of 57 trials (4%, 95% confidence interval 0% to 12%), overdiagnosis in four (7%, 2% to 18%), negative psychosocial consequences in five (9%, 3% to 20%), somatic complications in 11 (19%, 10% to 32%), use of invasive follow-up procedures in 27 (47%, 34% to 61%), all cause mortality in 34 (60%, 46% to 72%), and withdrawals because of adverse effects in one trial (2%, 0% to 11%). The median percentage of space in the results section that reported harms was 12% (interquartile range 2-19%).ConclusionsCancer screening trials seldom quantify the harms of screening. Of the 57 cancer screening trials examined, the most important harms of screening--overdiagnosis and false positive findings--were quantified in only 7% and 4%, respectively.
| S-EPMC4793399 | biostudies-literature
Project description:BACKGROUND:The Australian National Bowel Cancer Screening Programme (NBCSP) was introduced in 2006. When fully implemented, the programme will invite people aged 50 to 74 to complete an immunochemical faecal occult blood test (iFOBT) every 2 years. METHODS AND FINDINGS:To investigate colorectal cancer (CRC) screening occurring outside of the NBCSP, we classified participants (n = 2,480) in the Australasian Colorectal Cancer Family Registry (ACCFR) into 3 risk categories (average, moderately increased, and potentially high) based on CRC family history and assessed their screening practices according to national guidelines. We developed a microsimulation to compare hypothetical screening scenarios (70% and 100% uptake) to current participation levels (baseline) and evaluated clinical outcomes and cost for each risk category. The 2 main limitations of this study are as follows: first, the fact that our cost-effectiveness analysis was performed from a third-party payer perspective, which does not include indirect costs and results in overestimated cost-effectiveness ratios, and second, that our natural history model of CRC does not include polyp sojourn time, which determines the rate of cancerous transformation. Screening uptake was low across all family history risk categories (64%-56% reported no screening). For participants at average risk, 18% reported overscreening, while 37% of those in the highest risk categories screened according to guidelines. Higher screening levels would substantially reduce CRC mortality across all risk categories (95 to 305 fewer deaths per 100,000 persons in the 70% scenario versus baseline). For those at average risk, a fully implemented NBCSP represented the most cost-effective approach to prevent CRC deaths (AUS$13,000-16,000 per quality-adjusted life year [QALY]). For those at moderately increased risk, higher adherence to recommended screening was also highly cost-effective (AUS$19,000-24,000 per QALY). CONCLUSION:Investing in public health strategies to increase adherence to appropriate CRC screening will save lives and deliver high value for money.
| S-EPMC6095490 | biostudies-literature