Contemporary issues in the implementation of lung cancer screening

Lung cancer screening with low-dose computed tomography can reduce death from lung cancer by 20–24% in high-risk smokers. National lung cancer screening programmes have been implemented in the USA and Korea and are being implemented in Europe, Canada and other countries. Lung cancer screening is a process, not a test. It requires an organised programmatic approach to replicate the lung cancer mortality reduction and safety of pivotal clinical trials. Cost-effectiveness of a screening programme is strongly influenced by screening sensitivity and specificity, age to stop screening, integration of smoking cessation intervention for current smokers, screening uptake, nodule management and treatment costs. Appropriate management of screen-detected lung nodules has significant implications for healthcare resource utilisation and minimising harm from radiation exposure related to imaging studies, invasive procedures and clinically significant distress. This review focuses on selected contemporary issues in the path to implement a cost-effective lung cancer screening at the population level. The future impact of emerging technologies such as deep learning and biomarkers are also discussed.

Improved X-ray baggage screening sensitivity with ‘targetless’ search training

When searching for a known target, mental representations of target features, or templates, guide attention towards matching objects and facilitate recognition. When only distractor features are known, distractor templates allow irrelevant objects to be recognised and attention to be shifted away. This is particularly true in X-ray baggage search, a challenging real-world visual search task with implications for public safety, where targets may be unknown, difficult to predict and concealed by an adversary, but distractors are typically benign and easier to identify. In the present study, we draw on basic principles of distractor suppression and rejection to investigate a counterintuitive ‘targetless’ approach to training baggage search. In a simulated X-ray baggage search task, we observed significant benefits to target detection sensitivity (d′) for targetless relative to target-based training, but no effects of performance-contingent rewards or the inclusion of superordinate semantic categories during training. The benefits of targetless search training were most apparent for stimuli involving less spatial overlap (occlusion), which likely represents the difficulty and greater individual variation involved in searching more visually complex images. Together, these results demonstrate the effectiveness of a counterintuitive targetless approach to training target detection in X-ray baggage search, based on basic principles of distractor suppression and rejection, with potential for use as a real-world training tool.

Use of Low-Dose Tamoxifen to Increase Mammographic Screening Sensitivity in Premenopausal Women

Increased breast density decreases mammographic sensitivity due to masking of cancers by dense tissue. Tamoxifen exposure reduces mammographic density and, therefore, should improve screening sensitivity. We modelled how low-dose tamoxifen exposure could be used to increase mammographic sensitivity. Mammographic sensitivity was calculated using the KARMA prospective screening cohort. Two models were fitted to estimate screening sensitivity and detected tumor size based on baseline mammographic density. BI-RADS-dependent sensitivity was estimated. The results of the 2.5 mg tamoxifen arm of the KARISMA trial were used to define expected changes in mammographic density after six months exposure and to predict changes in mammographic screening sensitivity and detected tumor size. Rates of interval cancers and detection of invasive tumors were estimated for women with mammographic density relative decreases by 10–50%. In all, 517 cancers in premenopausal women were diagnosed in KARMA: 287 (56%) screen-detected and 230 (44%) interval cancers. Screening sensitivities prior to tamoxifen, were 76%, 69%, 53%, and 46% for BI-RADS density categories A, B, C, and D, respectively. After exposure to tamoxifen, modelled screening sensitivities were estimated to increase by 0% (p = 0.35), 2% (p < 0.01), 5% (p < 0.01), and 5% (p < 0.01), respectively. An estimated relative density decrease by ≥20% resulted in an estimated reduction of interval cancers by 24% (p < 0.01) and reduction in tumors >20 mm at detection by 4% (p < 0.01). Low-dose tamoxifen has the potential to increase mammographic screening sensitivity and thereby reduce the proportion of interval cancers and larger screen-detected cancers.

Study on the views and methods of ultrasonic screening and diagnosis for abnormal aortic arch in infants

Background The purpose of this study was to explore echocardiographic views and methods of aortic arch anomalies in infants, so as to improve the screening sensitivity and diagnostic accuracy. Methods 140 children with abnormal aortic arch diagnosed by ultrasound in Children’s Hospital of Hebei Province from January 2014 to December 2019 were selected for retrospective analysis. All were confirmed by surgery or/and computerized tomography angiography. Series of views for aortic arch (the three-vessel and tracheal view, aortic arch short axis view, left aortic arch long axis view, aortic arch long axis continuous scan views) were performed in all cases on the basis of the routine views of echocardiography. The screening sensitivity and diagnostic coincidence rate of different echocardiographic views for aortic arch anomalies were analyzed. Results Among the 140 infants, right aortic arch were 21 cases (6/21 were accompanied by mirror branch and 15/21 were with aberrant left subclavian artery). Left aortic arch with aberrant right subclavian artery were 2 cases, and double aortic arch with both arches open were 20 cases. Double aortic arch with left arch atresia were 2 cases, and atresia of the proximal aorta with aortic arch dysplasia was 1 case. Coarctation of the aorta were 67 cases, and interruption of aortic arch were 27 cases. All the patients were correctly diagnosed except that 2 infants with interruption of aortic arch were incorrectly diagnosed as coarctation of the aorta, and 1 infant with coarctation of the aorta was misdiagnosed as interruption of aortic arch by echocardiography. The screening sensitivities of four views and four-view combination for abnormal aortic arch were 99.3, 73.6, 87.1, 99.3, and 100%; the diagnostic coincidence rates were 85.7, 27.1,66.4, 95.0%, and 97.9% respectively. On the basis of traditional left aortic long axis view, other three views had their own advantages. The screening sensitivity and diagnostic coincidence rate of four-view combination were significantly improved. Conclusions The three-vessel trachea view is simple and feasible, which is suitable for screening abnormal aortic arch. The combination of four views conduces to improving screening sensitivity and diagnostic accuracy of aortic arch abnormalities.

Assessment of the Utility of Plusoptix A09 Handheld Photo-refractometer in Screening Refractory Errors and Amblyopia in Children

The aim of this study is to find out the frequency of anisometropic amblyopia in children and to increase awareness about this disease. All children between the ages of 4 and 10 years who were attending 11 kindergarten and primary schools determined by provincial directorate for national education in the center of Malatya were included. A screening team including interns and a resident from the Department of Pediatrics have used Plusoptix A09 handheld photo-refractometer device for detecting amblyopia and its reasons. A total of 7,000 students were screened. The mean age of the students was 7.4 ± 2 years. Amblyopia was suspected in 357 cases with the Plusoptix S09 screening. After eye examinations performed by an ophthalmologist, 303 cases were found to have pathologic eye examination. Amblyopia was found in 67 (18.8%) of the 303 cases, and anisometropic amblyopia was found in 59 of 67 cases. As a result of the screening, sensitivity of Plusoptix A09 was found to be 88.1%, while its specificity was found to be 88.6%. Its positive predictive value was found to be 64.0% and its negative predictive value was found to be 97.0%. We believe that with screenings performed by health professionals who are given short-term training by using a device that can conduct remote measurements, detection of anisometropic amblyopia, which is the most frequent reason for amblyopia, can be done in a fast and relatively less expensive way and with the minimum number of specialist physician required. This way, children with amblyopia can reach the ophthalmologist earlier for treatment.

Co-Testing

The dramatic decline in cervical cancer in women is attributable first to screening with the Papanicolaou (Pap) test, followed later by the addition of the Human Papilloma Virus (HPV) test, which enhanced screening sensitivity. In association with this excellent performance record, resulting from the combination of Pap Test and HPV Test, known also as Co-Testing, the current standard of care for cervical cancer screening for most women (those over 30) is Co-Testing with Pap + HPV tests, as currently recommended by U.S. guidelines. The challenge is to improve screening cost-effectiveness without compromising efficacy. The notion that screening with one test may be more cost-effective than two tests seems reasonable upon first consideration, but closer examination may dispute this assumption. The chapter aims to analyze costs and benefits regarding optimal screening method for daily clinical practice.