Population Screening for Lung Cancer

Lung Cancer is now the commonest cause of premature death in our industrial conurbations. It presents late and tends to be investigated on prolonged pathways, often with a stage shift along the way. Survival rates are closely related to stage at diagnosis, leading to a number of approaches to early diagnosis, most of which have not been validated as population screening tools. Most early screening trials used imaging, sometimes supplemented by sputum cytology, and achieved improved survival but did not reduce overall mortality, a rigorous benchmark that avoids the pitfalls of lead-time bias and overdiagnosis. The landmark National Lung Cancer Screening Study (NLST) a targeted screening study now nearly a decade old, achieved a 20% mortality improvement but this did not lead to the clinical implementation of screening programs in Europe or in the UK, where there is still an unaccountable scepticism, despite recent confirmatory evidence that the targeted screening of highrisk populations can save many lives. The Manchester implementation pilot used community-based health-checks and CT scans to access a very deprived population, detecting one lung cancer for every 23 scans, most at early stage and nearly all suitable for curative-intent treatments, with the almost complete avoidance of inappropriate interventions for non-malignant disease. Substantial numbers of non-malignant respiratory and cardiac conditions were also identified and referred for treatment. The programme is now being rolled out across the Greater Manchester conurbation and has been incorporated into the NHS Long-term Plan. It is to be hoped that the implementation of targeted screening, together with a step-change in the pace of diagnostic and treatment pathways, will start to make a real difference, assisted by a reinvigoration of evidence-based smoking cessation programmes for this uniquely preventable disease.

Keywords: Cytology, DNA biomarkers, Fluorescence bronchoscopy, Lung cancer, Mortality, NHS plan, Risk-assessment, Screening, Stage-shift, VOC’s.