Overdiagnosis In Screening Research Articles

Overdiagnosis and overtreatment of ground-glass nodule-like lung cancer.

Lung cancer has had one of the highest incidences and mortality in the world over the last few decades, which has aided in the promotion and popularization of screening for lung ground-glass nodules (GGNs). People have great psychological anxiety about GGN because of the chance that it will develop into lung cancer, which makes clinical treatment of GGN a generally excessive phenomenon. Overdiagnosis in screening has recently been mentioned in the literature. An important research emphasis of screening is how to reduce the incidence of overdiagnosis and overtreatment. This paper discusses from different aspects how to characterize the occurrence of overdiagnosis and overtreatment, how to reduce overdiagnosis and overtreatment, and future screening, follow-up, and treatment approaches.

Do doctors and other healthcare professionals know overdiagnosis in screening and how are they dealing with it? A protocol for a mixed methods systematic review

IntroductionOverdiagnosis is the diagnosis of a disease that would never have caused any symptom or problem. It is a harmful side effect of screening and may lead to unnecessary treatment,...

Estimation of overdiagnosis by detection to incidence ratio in cancer screening.

Objective We aimed to introduce a concept of overdiagnosis with actual formulae. In screening for invasive cancer, the detection proportion to incidence rate (D/I) ratio is used as an intermediate indicator of effect. D is the detection rate (proportion) at screen and I is the background risk (i.e. the expected incidence rate if there were no screening). We sought to determine a proper use of the D/I ratio in the estimation of overdiagnosis in screening. Methods We propose the difference between the D/I ratio per year and incidence-based sensitivity as an estimate of overdiagnosis. As an example to evaluate this, we used screening for colorectal cancer, run as a randomized public health policy in Finland. Conclusion The use of the D/I ratio is inappropriate in predicting effect, and we recommend that the D/I ratio be used as a component in the estimation of overdiagnosis in screening for invasive cancer.

The Barrier to Informed Choice in Cancer Screening: Statistical Illiteracy in Physicians and Patients.

An efficient health care requires both informed doctors and patients. Our current healthcare system falls short on both counts. Most doctors and patients do not understand the available medical evidence. To illustrate the extent of the problem in the setting of cancer screening: In a representative sample of some 5000 women in nine European countries, 92% overestimated the reduction of breast cancer mortality by mammography by a factor of 10-200, or did not know. For a similar sample of about 5000 men with respect to PSA screening, this number was 89%. Of more than 300 US citizens who regularly attended one or more cancer screening test, more than 90% had never been informed about the biggest harms of screening-overdiagnosis and overtreatment-by their physicians. Among 160 German gynecologists, some 80% did not understand the positive predictive value of a positive mammogram, with estimates varying between 1 and 90%. In a national sample of 412 US primary care physicians, 47% mistakenly believed that if more cancers are detected by a screening test, this proves that the test saves lives, and 76% wrongly thought that if screen-detected cancers have better 5-year survival rates than cancers detected by symptoms, this would prove that the screening test saves lives. And of 20 German gynecologists, not a single one provided a woman with all information on the benefits and harms of cancer screening required in order to make an informed choice. Why is risk literacy so scarce in health care? One frequently discussed explanation assumes that people suffer from cognitive deficits that make them predictably irrational and basically hopeless at dealing with risks, so that they need to be "nudged" into healthy behavior. Yet research has demonstrated that the problem lies less in stable cognitive deficits than in how information is presented to physicians and patients. This includes biased reporting in medical journals, brochures, and the media that uses relative risks and other misleading statistics, motivated by conflicts of interest and defensive medicine that do not promote informed physicians and patients. What can be done? Every medical school should teach its students how to understand evidence in general and health statistics in particular. To cultivate informed patients, elementary and high schools should start teaching the mathematics of uncertainty-statistical thinking. Guidelines about complete and transparent reporting in journals, brochures, and the media need to be better enforced, and laws need to be changed in order to protect patients and doctors alike against the practice of defensive medicine instead of encouraging it. A critical mass of informed citizens will not resolve all healthcare problems, but it can constitute a major triggering factor for better care.

The role of pre-invasive disease in overdiagnosis: A microsimulation study comparing mass screening for breast cancer and cervical cancer.

Although early detection of cancer through screening can prevent cancer deaths, a drawback of screening is overdiagnosis. Overdiagnosis has been much debated in breast cancer screening, but less so in cervical cancer screening. We examined the impact of overdiagnosis by comparing two screening programmes in the Netherlands. We estimated overdiagnosis rates by microsimulation for breast cancer screening and cervical cancer screening, using a cohort of women born in 1982 with lifelong follow-up. Overdiagnosis estimates were made analogous to two definitions formed by the UK 2012 breast screening review. Pre-invasive disease was included in both definitions. Screening prevented 921 cervical cancers (-55%) and 378 cervical cancer deaths (-59%), and 169 (-1.3%) breast cancer cases and 970 breast cancer deaths (-21%). The cervical cancer overdiagnosis rate was 74.8% (including pre-invasive disease). Breast cancer overdiagnosis was estimated at 2.5% (including pre-invasive disease). For women of all ages in breast cancer screening, an excess of 207 diagnoses/100,000 women was found, compared with an excess of 3999 diagnoses/100,000 women in cervical cancer screening. For breast cancer, the frequency of overdiagnosis in screening is relatively low, but consequences are evident. For cervical cancer, the frequency of overdiagnosis in screening is high, because of detection of pre-invasive disease, but the consequences per case are relatively small due to less invasive treatment. This illustrates that it is necessary to present overdiagnosis in relation to disease stage and consequences.

Sensitivity, effect and overdiagnosis in screening for cancers with detectable pre-invasive phase.

Studies on cancer screening often evaluate the performance by indirect indicators. In case the screening detects pre-invasive lesions, they may be a mixture of benefit of sensitivity and effect as well as of harm of overdiagnosis. Here, we develop the formulae for the sensitivity, the effect and overdiagnosis in screening for pre-invasive lesions of cancer. Sensitivity is the ability of screening to identify a progressive lesion at the level of test (relevant for the laboratory), episode (relevant in the clinic) and programme (relevant at the population level). Effect is reduction of cancer incidence in those screened (efficacy) and in the target population (effectiveness). The sensitivity is estimated by interval cancers between two consecutive screens (incidence method) and the effect by interval cancers and cancers detected at the subsequent screen. Overdiagnosis is estimated as the detection rate of pre-invasive lesions minus the rate of invasive cancer prevented by screening in one screening round. All the indicators are corrected for nonattendance and selective attendance by disease risk. The population to be followed and the period of follow-up are defined for each indicator separately. Data on cervix cancer screening with Papnet® automation device are given as an example. Estimation of sensitivity and effect are consistent with the purpose of the screening to prevent invasive disease. We further define the purpose at the level of laboratory, clinical medicine and public health and derive six estimators corresponding to the specific purposes considered in our article.

Quantification of harms in cancer screening trials: literature review

Objectives To assess how often harm is quantified in randomised trials of cancer screening.Design Two authors independently extracted data on harms from randomised cancer screening trials. Binary outcomes were described...

Overdiagnosis in screening mammography in Denmark: population based cohort study

Objective To use data from two longstanding, population based screening programmes to study overdiagnosis in screening mammography.Design Population based cohort study.Setting Copenhagen municipality (from 1991) and Funen County (from 1993),...

A population-based cohort study of chest x-ray screening in smokers: lung cancer detection findings and follow-up.

BackgroundCase-control studies of mass screening for lung cancer (LC) by chest x-rays (CXR) performed in the 1990s in scarcely defined Japanese target populations indicated significant mortality reductions, but these results are yet to be confirmed in western countries. To ascertain whether CXR screening decreases LC mortality at community level, we studied a clearly defined population-based cohort of smokers invited to screening. We present here the LC detection results and the 10-year survival rates.MethodsThe cohort of all smokers of > 10 pack-years resident in 50 communities of Varese, screening-eligible (n = 5,815), in July 1997 was invited to nonrandomized CXR screening. Self-selected participants (21% of cohort) underwent screening in addition to usual care; nonparticipants received usual care. The cohort was followed-up until December 2010. Kaplan-Meier LC-specific survival was estimated in participants, in nonparticipants, in the whole cohort, and in an uninvited, unscreened population (control group).ResultsOver the initial 9.5 years of study, 67 LCs were diagnosed in screening participants (51% were screen-detected) and 178 in nonparticipants. The rates of stage I LC, resectability and 5-year survival were nearly twice as high in participants (32% stage I; 48% resected; 30.5% 5-year survival) as in nonparticipants (17% stage I; 27% resected; 13.5% 5-year survival). There were no bronchioloalveolar carcinomas among screen-detected cancers, and median volume doubling time of incidence screen-detected LCs was 80 days (range, 44-318), suggesting that screening overdiagnosis was minimal. The 10-year LC-specific survival was greater in screening participants than in nonparticipants (log-rank, p = 0.005), and greater in the whole cohort invited to screening than in the control group (log-rank, p = 0.001). This favourable long-term effect was independently related to CXR screening exposure.ConclusionIn the setting of CXR screening offered to a population-based cohort of smokers, screening participants who were diagnosed with LC had more frequently early-stage resectable disease and significantly enhanced long-term LC survival. These results translated into enhanced 10-year LC survival, independently related to CXR screening exposure, in the entire population-based cohort. Whether increased long-term LC-specific survival in the cohort corresponds to mortality reduction remains to be evaluated.Trial registration numberISRCTN90639073

Over-diagnosis in screening by mammography: A follow-up of the Malmö Mammographic Screening Trial, MMST

Breast screening with full-field digital mammography (FFDM) fails to detect 15–30% of cancers. This figure is higher for women with dense breasts. A new tomographic technique in mammography has been developed — digital breast tomosynthesis (DBT) — which allows images to be viewed in sections through the breast and has the potential to improve cancer detection rates. Results from retrospective reading studies comparing DBT with FFDM have been largely favourable with improvement in sensitivity and specificity. Increases in diagnostic accuracy have been reported as being independent of breast density; however there are mixed reports regarding the detection of microcalcification. Prospective screening studies using DBT with FFDM have demonstrated increased rates in cancer detection compared with FFDM alone. A reduction in false-positive recall rates has also been shown. Screening with the addition of DBT would approximately double radiation dose; however a simulated FFDM image can be generated from a DBT scan. The combination of simulated FFDM images and DBT is being evaluated within several studies and some positive results have been published. Interval cancer rates for the UK National Health Service Breast Screening Programme (NHSBSP) demonstrate the limited sensitivity of FFDM in cancer detection. DBT has the potential to increase sensitivity and decrease false-positive recall rates. It has approval for screening and diagnostics in several countries; however, there are issues with DBT as a screening tool including additional reading time, IT storage and connectivity, over-diagnosis, and cost effectiveness. Feasibility and cost-effectiveness trials are needed before the implementation of DBT in NHSBSP can be considered.

Overdiagnosis in screening: is the increase in breast cancer incidence rates a cause for concern?

Overdiagnosis in screening: is the increase in breast cancer incidence rates a cause for concern?

Overdiagnosis in screening: is the increase in breast cancer incidence rates a cause for concern?

To estimate the degree of overdiagnosis of breast cancer in a mammographic screening programme. A mammography service screening programme in Florence, Italy. We studied the incidence of breast cancer in Florence between 1990 and 1999, following the introduction of screening in 1990. Incidence of breast cancer in this period was compared with incidence between 1985 and 1989, before the introduction of screening. It was necessary to estimate the number of cancers that would have arisen in the absence of screening, but after the end of followup (31 December 1999), so that these were not misclassified as overdiagnosed tumours. Around 60,000 women aged 50-69 were invited for screening during the period of study. There were 2780 breast cancers diagnosed during the period of study (2626 were invasive). There was no significant evidence of overdiagnosis of invasive cancers. When invasive and in situ cancers were considered together, around 5% of cases were overdiagnosed. There is a small amount of overdiagnosis of ductal carcinoma in situ in mammography screening; however, this should not deter women from being screened. Training and practice in mammographic screening should emphasise detection of small, invasive lesions. Research into the natural history and treatment of the disease should aim at minimising overtreatment of those in situ lesions that are less likely to progress to invasive disease.